Ringed Seal (Pusa hispida): COSEWIC assessment and status report 2019

Official title: COSEWIC Assessment and Status Report on the Ringed Seal (Pusa hispida) in Canada 2019

Committee on the status of Endangered Wildlife in Canada (COSEWIC)
Préoccupante 2019

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Cover photo
Ringed Seal
Long description 

COSEWIC status reports are working documents used in assigning the status of wildlife species suspected of being at risk. This report may be cited as follows:

COSEWIC. 2019. COSEWIC assessment and status report on the Ringed Seal Pusa hispida in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xii + 82 pp. (Species at risk public registry).

Previous report(s):

Kingsley, Michael C.S. 1989. COSEWIC status report on the Ringed Seal Pusa hispida in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. 27 pp.

Production note: COSEWIC would like to acknowledge Jeff W. Higdon, Stephen D. Petersen, and Meagan Hainstock for writing the status report on Ringed Seal, Pusa hispida, in Canada, prepared under contract with Environment and Climate Change Canada. This report was overseen and edited by David Lee, Co-chair of the COSEWIC Marine Mammals Specialist Subcommittee.

For additional copies contact:

COSEWIC Secretariat
c/o Canadian Wildlife Service
Environment and Climate Change Canada
Ottawa ON K1A 0H3

Tel.: 819-938-4125
Fax: 819-938-3984
E-mail: ec.cosepac-cosewic.ec@canada.ca
www.cosewic.ca

Également disponible en français sous le titre Évaluation et Rapport de situation du COSEPAC sur le Phoque annelé (Pusa hispida) au Canada.

Cover illustration/photo: Ringed Seal on spring ice near Churchill, Manitoba – Photo by S.D. Petersen.

COSEWIC assessment summary

Assessment Summary – November 2019

Common name: Ringed Seal

Scientific name: Pusa hispida

Status: Special Concern

Reason for designation: This small seal needs sea ice to thrive. It is wide-ranging and is the most abundant marine mammal in the Canadian Arctic. It is an important species for Inuit and is the primary prey of Polar Bear. Its population levels and trends are uncertain, although the total population is about 2 million individuals. Aboriginal Traditional Knowledge from local communities across the species’ range suggests that its population status varies regionally, but is generally considered stable. Reductions in the area and duration of sea ice due to climate warming in the Canadian Arctic, with consequent reductions in suitable pupping habitat due to loss of stable ice and a lower spring snow depth, are the primary threats to this species. The Canadian population is predicted to decline over the next three generations, and may become Threatened due to extensive and ongoing changes in sea ice and snow cover in a rapidly warming Arctic.

Occurrence: Manitoba, Ontario, Québec, Newfoundland and Labrador, Yukon, Northwest Territories, Nunavut, Pacific Ocean, Arctic Ocean, Atlantic Ocean

Status history: Designated Not at Risk in April 1989. Status re-examined and designated Special Concern in November 2019.

COSEWIC executive summary

Ringed Seal
Pusa hispida

Wildlife Species Description and Significance

Ringed Seal is a phocid seal with five subspecies, one of which occurs in Canada: Arctic Ringed Seal (Pusa hispida hispida). They are one of the smallest pinnipeds, with average adults being 1.5 m long and weighing 70 kg—males being slightly larger than females. Ringed Seal is important both economically and culturally to northern peoples and are important prey for the Polar Bear (Ursus maritimus).

Distribution

Ringed Seal has a circumpolar distribution over Arctic and subarctic waters, relying on sea ice as habitat. Their Canadian distribution ranges from Yukon in the west to southern Labrador in the east, with occasional sightings of vagrants south of the seasonal ice zone in both Pacific and Atlantic Oceans.

Habitat

Ringed Seal is strongly ice-adapted. Their habitat requirements follow the annual cryogenic cycle, with adults establishing territories during fall freeze-up. Prime breeding habitats occur on stable ice, which tends to be landfast ice occurring over relatively shallow waters (< 150 m). Breeding also occurs on mobile pack ice. Ringed Seal moults on sea ice in late spring and is widely distributed over waters of varying depths during the open-water season, presumably in response to prey distribution. Ringed Seal can be negatively affected by both extreme heavy-ice years (longer ice seasons) and extreme low-ice years (short spring ice seasons).

Biology

The Ringed Seal mating system is thought to be one of weak polygyny, but observations suggest that alternative strategies exist depending on region. Gestation (10–11 months) is divided into ~2–3 months of embryonic diapause and ~8 months of fetal growth. Pups are born in spring, in subnivean birth lairs, and are nursed for 5–8 weeks. Females mate near the end of lactation or directly after. Age at maturity is variable, but is 6 years on average, with males entering the breeding population later than females. Maximum life span has been recorded at 45 years, but average adult life span is likely about 20 years.

During the open-water season, they feed on a wide variety of pelagic and benthic prey to build up blubber reserves. The most common prey across their range are pelagic schooling fish such as Arctic Cod (Boreogadus saida), Sand Lance (Ammodytes spp.) and Capelin (Mallotus villosus), as well as amphipods, euphausiids, shrimp and other crustaceans.

Individual movements are variable across the range and are dictated by prey distribution. Movements can be extensive during the open-water season, and likely consist of both seasonal migrations and dispersal events for subadults. At freeze-up, when adults move into breeding areas and establish territories, subadults are either driven out or choose areas of mobile ice and polynyas where the costs of maintaining breathing holes are lower. Adults have been shown to exhibit breeding site fidelity.

Ringed Seal is the primary prey for the Polar Bear but is also preyed upon by Killer Whales (Orcinus orca), Walruses (Odobenus rosmarus), Greenland Sharks (Somniosus microcephalus), and humans. The Arctic Fox (Vulpes lagopus) can also be important predators on pups, particularly when snow cover is very low.

Population Sizes and Trends

Most information on Ringed Seal population size comes from aerial surveys, which are conducted when seals are hauled out on ice to moult. Because these surveys are sporadic and localized, estimates are uncertain and dated. However, species abundance is thought to be high, with an estimated 2.3 million seals (1.15 million mature individuals) in Canada and adjacent waters (West Greenland, Alaska, Russian Federation).

Threats and limiting factors

The Arctic has undergone substantial climatic change since the late 1970s: annual, perennial, and multi-year Arctic sea ice extent, as well as Arctic sea ice thickness and volume, have decreased while the Arctic ice-free season has lengthened. Over the 1967-2012 period, Northern Hemisphere snow cover extent also decreased in all months and especially during spring. For ice-dependent Arctic marine mammals such as Ringed Seal, these extensive unidirectional changes in sea ice and snow cover can equate to habitat loss and cascading ecological impacts. For example, a very warm year in 2010 resulted in poor Ringed Seal body condition in Hudson Bay. Seals experienced increased stress, giving birth to fewer pups in the following years. In the long term, the loss of habitat due to climate change poses the most significant threat. Decreases in sea ice extent also increase opportunities for commercial shipping, tourism and industrial development, which could increase disturbance, habitat modification and pollutants. Predation by the Polar Bear is the most significant mortality source. Hunting by humans may also be a limiting factor, but removal rates are likely an order of magnitude lower than those for Polar Bear. Pollutant levels are variable amongst regions, with some levels of increase having known effects on Polar Bear but unknown effects on seals.

Protection, Status and Ranks

There are no international agreements or conventions specifically intended to protect Ringed Seal, but the International Agreement on the Conservation of Polar Bears and their Habitat provides some measure of protection. Ringed Seal is not listed on any appendices of the Convention on International Trade in Endangered Species, and they are “Least Concern” on the International Union for the Conservation of Nature (IUCN) Red List (as both species and Arctic subspecies). They are ranked “N5B, N5N, N5M” in the latest Wild Species (General Status) Report (CESCC 2016). COSEWIC assessed the species as Special Concern in November 2019; it was previously assessed as “Not at Risk” in 1989, and they are currently not listed under the Species at Risk Act. The Arctic subspecies is listed as threatened under the United States Endangered Species Act. Ringed Seal is ranked as Least Concern in Greenland, Vulnerable in Norway (Svalbard), and is not listed in Russia.

In Canada, Ringed Seal is managed under the authority of the Marine Mammal Regulations (SOR/93-56) of the Fisheries Act. Seal hunting in marine waters of the Northwest Territories, Nunavut, Nunavik and Labrador are co-managed by various wildlife management boards, with scientific advice from the Department of Fisheries and Oceans. Existing national parks, national wildlife areas and other lands owned and managed by the Government of Canada afford little habitat protection. Existing and proposed marine protected areas and national marine conservation areas potentially afford some protection.

Technical summary

Pusa hispida

Ringed Seal

Phoque annelé

Netsik, netsuk

Range of occurrence in Canada: Manitoba, Ontario, Québec, New Brunswick (occasional), Nova Scotia (occasional), Prince Edward Island (occasional), Newfoundland and Labrador, Yukon, Northwest Territories, Nunavut, Pacific Ocean, Arctic Ocean, Atlantic Ocean

Demographic Information
Summary items Information

Generation time (usually average age of parents in the population; indicate if another method of estimating generation time indicated in the IUCN guidelines (2011) is being used)

13 years, based on age of first reproduction = 6, and assuming an average lifespan of 20 years.

Is there an [observed, inferred, or projected] continuing decline in number of mature individuals?

Unknown

Estimated percent of continuing decline in total number of mature individuals within [5 years or 2 generations]

Unknown

[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over the last [10 years, or 3 generations].

Unknown

[Projected or suspected] percent [reduction or increase] in total number of mature individuals over the next [10 years, or 3 generations].

Reduction expected but uncertainty exists on quantifying the reduction.

Unknown

[Observed, estimated, inferred, or suspected] percent [reduction or increase] in total number of mature individuals over any [10 years, or 3 generations] period, over a time period including both the past and the future.

Unknown

Are the causes of the decline a. clearly reversible and b. understood and c. ceased?

Not applicable

Are there extreme fluctuations in number of mature individuals?

No

Extent and Occupancy Information
Summary items Information

Estimated extent of occurrence (EOO)

4,403,651 km2 (8,146,022 km2 w/ land included)

Index of area of occupancy (IAO)

(Always report 2x2 grid value).

3,984,076 km2 (996,019 grid cells)

Is the population “severely fragmented” i.e., is >50% of its total area of occupancy in habitat patches that are (a) smaller than would be required to support a viable population, and (b) separated from other habitat patches by a distance larger than the species can be expected to disperse?

a. No

b. No

Number of “locations”*(use plausible range to reflect uncertainty if appropriate)

Unknown

Is there an [observed, inferred, or projected] decline in extent of occurrence?

Yes – Projected retraction in southern range due to habitat deterioration

Is there an [observed, inferred, or projected] decline in index of area of occupancy?

Yes – Projected retraction in southern range due to habitat deterioration

Is there an [observed, inferred, or projected] decline in number of subpopulations?

Unknown

Is there an [observed, inferred, or projected] decline in number of “locations”*?

Unknown

Is there an [observed, inferred, or projected] decline in [area, extent and/or quality] of habitat?

Yes – Observed decline in sea ice area, extent, quality and persistence. Projected loss of sea ice due to climate change.

Are there extreme fluctuations in number of subpopulations?

Unknown

Are there extreme fluctuations in number of “locations”?

N/A

Are there extreme fluctuations in extent of occurrence?

No

Are there extreme fluctuations in index of area of occupancy?

No – There is some annual variation in extent and distribution of sea ice that could influence distribution of breeding habitat

* See definitions and abbreviations on COSEWIC website and International Union for Conservation of Nature (IUCN) (Feb 2014) for more information on this term.

Number of Mature Individuals (in each subpopulation)
Subpopulations (give plausible ranges) N Mature Individuals

Total

1.15 million

(assuming 50% adults as per IUCN)

One large population - entire Canadian range and also shared with Greenland, United States (Alaska), and Russian Federation. No complete comprehensive population survey has ever been undertaken.

Total

1.15 million

Quantitative Analysis
Is the probability of extinction in the wild at least [20% within 20 years or 5 generations, or 10% within 100 years]? Unknown; data for quantitative analysis lacking

Threats (direct, from highest impact to least, as per IUCN Threats Calculator)

Was a threats calculator completed for this species? Yes

i. High impact threat – Habitat loss caused by human-induced climate change

ii. Negligible impact threats – Energy production and mining, Transportation and service corridors, Biological resource use, Natural systems modifications

Limiting factors – Predation

Rescue effect (immigration from outside Canada)
Summary items Information

Status of outside population(s) most likely to provide immigrants to Canada.

USA – Threatened

Greenland – Least Concern

Russia – no listing

Is immigration known or possible?

Yes. Animals presently migrate between countries.

Would immigrants be adapted to survive in Canada?

Yes

Is there sufficient habitat for immigrants in Canada?

Yes

Are conditions deteriorating in Canada?+

Changes in sea ice conditions in the short term are subject to high spatiotemporal variability but long term trend is decline in sea ice conditions.

Uncertain

Are conditions for the source (i.e., outside) population deteriorating?

Uncertain

Is the Canadian population considered to be a sink1?

No

Is rescue from outside populations likely?

Yes

+ See Table 3 (Guidelines for modifying status assessment based on rescue effect).

Data Sensitive Species

Is this a data sensitive species? No

Status History

COSEWIC: Designated Not at Risk in April 1989. Status re-examined and designated Special Concern in November 2019.

Status and Reasons for Designation:

Status: Special Concern

Alpha-numeric codes: Not applicable

Reasons for designation: This small seal needs sea ice to thrive. It is wide-ranging and is the most abundant marine mammal in the Canadian Arctic. It is an important species for Inuit and is the primary prey of Polar Bear. Its population levels and trends are uncertain, although the total population is about 2 million individuals. Aboriginal Traditional Knowledge from local communities across the species’ range suggests that its population status varies regionally, but is generally considered stable. Reductions in the area and duration of sea ice due to climate warming in the Canadian Arctic, with consequent reductions in suitable pupping habitat due to loss of stable ice and a lower spring snow depth, are the primary threats to this species. The Canadian population is predicted to decline over the next three generations, and may become Threatened due to extensive and ongoing changes in sea ice and snow cover in a rapidly warming Arctic.

Applicability of Criteria

Criterion A (Decline in Total Number of Mature Individuals): Not applicable. Population is likely near 2.3 million individuals. A decline is projected due to loss of suitable habitat in three generations but there remains uncertainty over the actual population response which negates a quantification of that decline.

Criterion B (Small Distribution Range and Decline or Fluctuation): Not applicable. Range greatly exceeds thresholds; population is not fragmented and does not undergo extreme fluctuations. Decline is projected in quality of habitat.

Criterion C (Small and Declining Number of Mature Individuals): Not applicable. A continuing decline is projected, and the population exists as one subpopulation but likely near 1.15 million mature individuals.

Criterion D (Very Small or Restricted Population): Not applicable. Population size and range exceed thresholds.

Criterion E (Quantitative Analysis): Not applicable.

Preface

Canadian Ringed Seal populations were last assessed by COSEWIC as Not at Risk in April 1989 (Kingsley 1990). Much has been learned about Ringed Seal biology since they were last assessed, but there remain large gaps in our knowledge of the species.

Although Ringed Seal is now placed in a different genus than it was in the last assessment, this has more to do with the taxonomy of Grey Seals than a change that would have implications for the assessment process. Several population genetics studies reveal an overall pattern of isolation by distance, but none suggests that multiple designatable units are present.

Challenges in surveying Ringed Seal remain because they are difficult to detect in water during summer and may be hidden under sea ice and snow in winter. Aerial surveys are timed for the spring, when much of the population is hauled out on the ice to moult. The percentage of animals hauled out at any one time changes over the season and fluctuates during the day based on weather conditions—leading to uncertainty in seal estimates for most areas. This challenge, coupled with the very large range over which Ringed Seal is found, means that only a very small portion of their range has been surveyed and even less of their range is surveyed on a regular basis. These factors have led to the generation of a conservative estimate of population size (2.3 million) and very few areas with data to determine trend.

Community-based harvest monitoring has shown large fluctuations in pup production over time, relating to both exceptionally heavy and light ice years (shorter or longer open-water seasons). This connection between ice and snow conditions and Ringed Seal productivity is problematic because reductions in ice extent and ice cover duration, as well as increased ice mobility, are current trends being observed. Additional changes in the timing and amount of precipitation may be having, or will have, significant effects on Ringed Seal habitat. Currently, there are no strong indications that Ringed Seal numbers are declining in Canada, except in western Hudson Bay where estimated numbers have been declining since the 1990s, but surveys are increasingly difficult to undertake due to changing environmental conditions (e.g., early break-up and increased fog).

Ringed Seal is ubiquitous in the Arctic and subarctic, where they are economically and culturally important for northern peoples and are the major prey of Polar Bear. Climate change-induced habitat loss will significantly impact distribution and numbers. For this reason, other jurisdictions outside Canada have listed Ringed Seal as a species at risk.

Detailed reviews are available for Ringed Seal (e.g., Reeves 1998; Kelly et al. 2010a; Kovacs 2014; Lowry 2016) and for the Arctic subspecies (e.g., Kingsley 1990; Boveng 2016a).

COSEWIC history

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) was created in 1977 as a result of a recommendation at the Federal-Provincial Wildlife Conference held in 1976. It arose from the need for a single, official, scientifically sound, national listing of wildlife species at risk. In 1978, COSEWIC designated its first species and produced its first list of Canadian species at risk. Species designated at meetings of the full committee are added to the list. On June 5, 2003, the Species at Risk Act (SARA) was proclaimed. SARA establishes COSEWIC as an advisory body ensuring that species will continue to be assessed under a rigorous and independent scientific process.

COSEWIC mandate

The Committee on the Status of Endangered Wildlife in Canada (COSEWIC) assesses the national status of wild species, subspecies, varieties, or other designatable units that are considered to be at risk in Canada. Designations are made on native species for the following taxonomic groups: mammals, birds, reptiles, amphibians, fishes, arthropods, molluscs, vascular plants, mosses, and lichens.

COSEWIC membership

COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Department of Fisheries and Oceans, and the Federal Biodiversity Information Partnership, chaired by the Canadian Museum of Nature), three non-government science members and the co-chairs of the species specialist subcommittees and the Aboriginal Traditional Knowledge subcommittee. The Committee meets to consider status reports on candidate species.

Definitions (2019)

Wildlife species
A species, subspecies, variety, or geographically or genetically distinct population of animal, plant or other organism, other than a bacterium or virus, that is wild by nature and is either native to Canada or has extended its range into Canada without human intervention and has been present in Canada for at least 50 years.
Extinct (X)
A wildlife species that no longer exists.
Extirpated (XT)
A wildlife species no longer existing in the wild in Canada, but occurring elsewhere.
Endangered (E)
A wildlife species facing imminent extirpation or extinction.
Threatened (T)
A wildlife species likely to become endangered if limiting factors are not reversed.
Special concern (SC)
(Note: Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.)
A wildlife species that may become a threatened or an endangered species because of a combination of biological characteristics and identified threats.
Not at risk (NAR)
(Note: Formerly described as “Not In Any Category”, or “No Designation Required.”)
A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.
Data deficient (DD)
(Note: Formerly described as “Indeterminate” from 1994 to 1999 or “ISIBD” [insufficient scientific information on which to base a designation] prior to 1994. Definition of the [DD] category revised in 2006.)
A category that applies when the available information is insufficient (a) to resolve a species’ eligibility for assessment or (b) to permit an assessment of the species’ risk of extinction.

The Canadian Wildlife Service, Environment and Climate Change Canada, provides full administrative and financial support to the COSEWIC Secretariat.

Wildlife species description and significance

Name and classification

Ringed Seal, Pusa hispida (Schreber, 1775) (Class: Mammalia, Order: Carnivora, Family: Phocidae, Subfamily: Phocinae), is a small earless (phocid) seal found throughout the Arctic and subarctic. Five subspecies are recognized, one of which, P. h. hispida, occurs in Canada (Rice 1998; Committee on Taxonomy 2014; Boveng 2016a; Lowry 2016). Common names for the species include the following: Ringed Seal, Arctic Ringed Seal, jar seal, fiord seal and common seal (English); phoque annelé and phoque marbré (French); Netsik (Inuit/Labrador); Nattiq (Inuit/North and East Baffin); Natiinat (Inuit); Natchiq, Natchiit and Natik (Inuit/North Slope); Natsiq/Natsik (Inuit/Nunavik and Nunavut); Natseq (Western Greenland); Ringsæl or netside (Danish); Norppa (Finnish); Ringsel (Norwegian); Ладожская нерпа (Russian); and Vikare (Swedish).

Ringed Seal is named in English and French for the ringed pattern that is visible on their coats.

The genus name for Ringed Seal has shifted back and forth between Pusa and Phoca in recent decades, with Pusa generally in favour at the current time (e.g., Rice 1998; Committee on Taxonomy 2014). Much of the debate has revolved around difficulties in reconciling molecular and morphological relationships between the Grey Seal (Halichoerus grypus) and Phoca/Pusa species (Rice 1998; Committee on Taxonomy 2014; Boveng 2016a; Lowry 2016). Several recent studies have grouped Halichoerus as a sister species to Pusa caspica (Caspian Seal) (i.e., a paraphyletic Pusa genus) (e.g., Árnason et al. 2006; Higdon et al. 2007; Nyakatura and Bininda-Emonds 2012), but other studies (e.g., Fulton and Strobeck 2010) have resolved Halichoerus as sister to the remaining members of the Phoca/Pusa species complex. The nomenclature for the species name (hispida) for the Arctic Ringed Seal has been widely accepted (Rice 1998; Boveng 2016a; Lowry 2016).

Throughout this document, unless otherwise indicated, Ringed Seal refers to Arctic Ringed Seal (Pusa hispida hispida).

Morphological description

Ringed Seal is one of the smallest true (or earless) seals, with typical adult body sizes of roughly 1.5 m in length and 70 kg in weight (Kelly et al. 2010a). At birth, Ringed Seal is about 60-65 cm in length and 4.5-5.0 kg in weight, with some variation between study areas (e.g., McLaren 1958a; Smith and Stirling 1975; Lydersen et al. 1992). Ringed Seal pups grow quickly, reaching four times their birth weight at weaning (Hammill and Smith 1991; Lydersen et al. 1992), and then lose weight for several months after weaning (Smith 1987). There is some slight sexual dimorphism. McLaren (1958a) sampled 24 one-year-old seals from the Canadian Arctic, reporting average lengths of 103 cm and 94 cm for males and females, respectively, which is longer than one-year-old seals measured in the Beaufort and Chukchi Seas (Frost and Lowry 1981).

Ringed Seal is dimorphic in pelage, with light and dark phases (McLaren 1966; Kelly 1981). Light-phase seals have a dark grey saddle with superimposed light rings and lightly coloured lateral and ventral surfaces, while dark-phase seals have a dark background with light rings overall (Kelly et al. 2010a). Head and flippers (fore and hind) are generally dark grey to black (Rice 1998).

Pups are born with a natal coat of white hair (lanugo), which is shed after 4-6 weeks before the pup is weaned. First-year animals are uniformly silver grey with faint rings (the “silver jar” of the fur trade) (McLaren 1958a; Smith and Taylor 1977), which become more obvious with age.

Population spatial structure and variability

Ringed Seal is distributed throughout the circumpolar Arctic and subarctic, where there is seasonal sea ice habitat. Throughout their range, several subspecies have been identified (see Taxonomy ), with the Arctic subspecies being the most broadly distributed and abundant.

Several studies have examined the population genetic structure of Ringed Seal using neutral nuclear microsatellite markers (Palo et al. 2001; Davis et al. 2008; Petersen 2008; Nyman et al. 2014; Hudson 2016) or using both mitochondrial and nuclear markers (Martinez-Bakker et al. 2013). These studies have included relatively few sample sites that are widely dispersed over the range. Current studies also use different combinations of microsatellite markers; therefore, differentiation is reported here in general terms rather than specific FST values. Measures of genetic differentiation are affected by the number and types of genetic markers used; thus, most studies are not directly comparable. However, all population genetic studies are broadly concordant in finding low levels of genetic differentiation across the entire range (Palo et al. 2001; Davis et al. 2008; Martinez-Bakker et al. 2013).

Palo et al. (2001) compared three locations, none within Canada, and found weak differentiation between Svalbard and the Baltic Sea. Similarly, when Davis et al. (2008) compared eight sites, including four in Canadian waters, they found little genetic differentiation over most of the range. Although samples from the White Sea on the northwest coast of Russia showed a low but significant FST difference compared to other sites, STRUCTURE (Pritchard et al. 2000) analysis (a Bayesian individual-based, rather than location-based analysis) failed to detect population structure (Davis et al. 2008).

Martinez-Bakker et al. (2013) noted that samples should ideally be taken during the breeding season to detect population structure because of the high mobility and movement patterns of Ringed Seal during the open-water season. When they examined samples from 11 sites across the range, including four Canadian sites in the Eastern Beaufort Sea, they observed high gene flow (low differentiation) among breeding locations and no differentiation among Eastern Beaufort Sea samples. When examining Ringed Seal from 12 communities in the Eastern Canadian Arctic, Petersen (2008) found low levels of genetic differentiation and no population genetic structure. Moreover, Hudson (2016) found no significant differentiation among 17 Canadian sites.

Sampling for population genetics has not been uniform across Ringed Seal’s Canadian or global range. Available samples tend to be collected near communities as part of community-based harvest monitoring (Petersen 2008), which leaves large portions of the Arctic unsampled. However, given that Ringed Seal have high genetic diversity, high mobility and long generation times, there is little expectation that gene flow is disrupted across the range (Petersen et al. 2010). Several papers with samples at various scales have also not detected high differentiation (Palo et al. 2001; Davis et al. 2008; Petersen 2008; Martinez-Bakker et al. 2013; Hudson 2016). This suggests that despite the gaps in sampling it is unlikely that genetic structure has gone undetected in the Canadian Arctic.

Designatable units

Designatable units can be defined within a species in Canada if there are recognized subspecies or varieties or if there is an argument for discrete units that are evolutionarily significant (COSEWIC 2014). To date, there is no evidence to suggest that Ringed Seal in Canada should be assessed as more than one designatable unit. A number of additional subspecies have been suggested in the past for Canada, including P. h. beaufortiana in the Beaufort Sea and P. h. soperi in Foxe Basin and on the west coast of Baffin Island (Anderson 1946; Hall and Kelson 1959; Amano et al. 2002). However, none of these has been further supported, and all are considered synonymous with P. h. hispida (Frost and Lowry 1981; Rice 1998; Amano et al. 2002).

Some authors have considered regions separately and thus implied some level of management unit division (Reeves 1998). For example, McLaren (1962) treated different Hudson Bay Trading posts independently in his analyses. In practice, Ringed Seal in the Western Arctic (NWT and Yukon) have been treated separately from the Eastern Arctic and Hudson Bay (Nunavut) but this is less of a management strategy and more a logistic one; monitoring methods are similar between regions (Ferguson pers. comm. 2017). Yurkowski et al. (2016a) compiled telemetry data from Ringed Seal throughout the Canadian Arctic, noting a westward movement of animals tagged in the Amundsen Gulf towards the Chukchi Sea and an eastward movement of seals tagged from Resolute Bay to Baffin Bay. However, Hudson (2016) did not detect significant genetic differentiation between Ringed Seal sampled in Ulukhaktok, the Northwest Territories (NWT) and Hudson Bay. Similarly, Beaufort Sea, Svalbard and Baltic Sea samples were not significantly differentiated (Martinez-Bakker et al. 2013).

Finley et al. (1983) suggested a reproductively isolated population of Ringed Seal inhabiting the pack ice of Baffin Bay. They observed morphological differences (pack ice seals were smaller) and gut parasite differences (pack ice seals had lower parasite loads) but could not genetically differentiate the two populations using isozymes (Finley et al. 1983). Although they noted that some differences could be due to differences in diet (i.e., a fish-based diet could lead to high parasite loads), they still proposed the offshore Baffin Bay area as a separate population. Inuit in Baffin Bay and the Labrador Sea have also identified physical differences between Ringed Seal in coastal versus pack ice regions (e.g., Williamson 1997; Rosing-Asvid 2010). Although there has been no subsequent study in this area, western Arctic research examining the distribution of Polar Bear (Ursus maritimus) predation on Ringed Seal suggests that competition for landfast ice habitat may force smaller adults to breed in offshore sub-optimal habitat (Pilfold et al. 2014).

There have been suggestions that differences in morphology, as well as clinal variations in size (i.e., larger seals at higher latitudes; Soper 1944, McLaren 1958a), could warrant population status (Fedoseev 1975; Finley et al. 1983). However, these differences are not supported by patterns of genetic differentiation at neutral genetic loci (Petersen 2008; Hudson 2016) and may be the result of differing areas having a longer duration of spring stable ice (McLaren 1958a) or higher productivity (Yurkowski et al. 2016c). Shorter nursing times may result in smaller animals at weaning, as well as smaller adults (McLaren 1958a).

Inland populations of Ringed Seal have been noted in Nettilling Lake (Baffin Island, Nunavut) and Lake Melville (Labrador, Newfoundland and Labrador) (Reeves 1998), but there are no genetic data to evaluate whether they represent unique populations. Overall, given the current state of information about Ringed Seal populations, there is no evidence to indicate that those in Canada should be assessed as more than one designatable unit.

Special significance

Ringed Seal is a very important food source for Inuit and their dogs, although their use as a source of fuel (oil) and clothing (furs) has declined (Kingsley 1990).

Seal pelts are still an important source of income for Inuit harvesters throughout the Canadian Arctic and subarctic. Seal hunting remains an important socio-economic activity (McLaren 1958b; Wenzel 1987; Pelly 2001; Furgal et al. 2002) even though sales of pelts to the Government of Nunavut Department of Environment’s Fur and Seal Program have declined (Ghazal pers. comm. 2017).

Ringed Seal is also the primary food source for Polar Bear, and access to seals is of critical importance to bear populations (Stirling and Archibald 1977; Smith 1980; Stirling and Derocher 1993) (see Interspecific interactions ). Ringed Seal is highly adapted to life in the Arctic marine environment (e.g., using breathing holes and snow lairs) (Smith and Stirling 1975; Smith 1976; Lydersen and Smith 1989) (see Physiology and adaptability ), and are considered an important indicator species for climate change effects (Laidre et al. 2008; Kovacs 2014) (see Threats and limiting factors ).

Distribution

Global range

Ringed Seal has a circumpolar distribution (Figure 1, from Kelly et al. 2010a) and are strongly ice associated throughout their range. Maximal winter sea-ice cover in the Arctic roughly defines the global range of Ringed Seal, although vagrants are sometimes observed farther south where sea ice does not occur (e.g., Sable Island and Gulf of Maine; Lucas and McAlpine 2002; Waring et al. 2004). The following countries have Ringed Seal in their territorial waters: Canada, Greenland, Norway, Russia, United States of America and the Baltic Sea states. They occur in the Bering, Chukchi, Beaufort, Barents, White, Kara, Laptev and East Siberian seas, as well as the Canadian Arctic Archipelago, Hudson Bay, Hudson Strait, Davis Strait, Baffin Bay and Labrador Sea (Boveng 2016a), in addition to occupying some lake and river systems in Canada.

Figure 1, read long description

Figure 1. Global range of the five Ringed Seal (Pusa hispida) subspecies, data from Kelly et al. (2010a). Only one subspecies, P. h. hispida (Arctic Ringed Seal), occurs in Canadian waters (map projection: North Pole Stereographic).

Long description 

Map showing the global ranges of the five Ringed Seal subspecies, only one of which, Pusa hispida hispida or Arctic Ringed Seal, occurs in Canadian waters.

Canadian range

Ringed Seal is widely distributed in Arctic and subarctic Canada, ranging from the Yukon North Slope (and into Alaska and Russia as a contiguous population) in the west and south and east to southern Labrador (Figure 2, from Kelly et al. 2010a). Their distribution ranges throughout the Arctic Ocean, north of Canada’s Arctic Islands, and into Greenland waters in eastern Baffin Bay and Davis Strait.

Figure 2, read long description

Figure 2. Geographic range of Ringed Seal (P. hispida hispida subspecies) in Canadian waters and adjacent areas. Ringed Seal is also found along the northern coastline of Newfoundland, and sporadic records exist for the other Atlantic provinces, but breeding range is limited by the availability of sea ice for pupping. Dotted black line shows limits of Canada’s Exclusive Economic Zone (EEZ). Data from Kelly et al. (2010a) (map projection: Canada Lambert Conformal Conic).

Long description 

Map of the geographic range of Ringed Seal, hispida subspecies, in Canadian waters and adjacent areas. The limits of Canada’s Exclusive Economic Zone are also shown.

Figure 2 shows Ringed Seal ranging south to southern Labrador. The area around Lake Melville, or slightly south along the coast, is thought to be a typical southern limit for pupping (due to ice availability) (Stenson pers. comm. 2017), but Ringed Seal is found all the way down the Labrador coast.

In winter, Ringed Seal move south with the ice and are hunted on Newfoundland’s northern peninsula and northeast coast. They are not as abundant as on the Labrador coast, but some are collected every year (Stenson pers. comm. 2017). Ringed Seal also occur, at least sporadically, on Québec’s lower north shore, east of Anticosti, but there is little information available and collections have not been made in many years (Hammill pers. comm. 2017). They have also been recorded on Sable Island (Lucas and McAlpine 2002). Some range maps exclude James Bay, but Ringed Seal is known to occur throughout the area (Smith 1975; Gosselin pers. comm. 2017).

Extent of occurrence and area of occupancy

Ringed Seal has an extent of occurrence (EOO) of 8,146,022 km2, including land, in Canada (4,403,651 km2 with land excluded, i.e., ca. 45% land within the minimum convex polygon (MCP)), and an index of area of occupancy (IAO) of 996,019 2 km by 2 km grid cells = 3,984,076 km2. Values for EOO and IAO were not reported in the last COSEWIC assessment (Kingsley 1990), but the geographic range of Ringed Seal in Canada has not changed significantly since that time. Calculations were made using the range map in Kelly et al. (2010a), which was clipped to include the species’ range within the Canadian Exclusive Economic Zone only.

Ringed Seal moves from Canadian waters into adjacent jurisdictions (Greenland, Alaska and Russia; see Dispersal and migration ), but the boundaries of any population are uncertain. Information on the distribution of the species’ most limiting habitat (e.g., pupping areas, critical habitat, etc.) is not known, so IAO was calculated as the number of cells over species observation/distribution records. The IAO calculation reported here uses the full Canadian range. Landfast ice could be considered the most limiting habitat for Ringed Seal because birth lairs are usually found in this habitat, but Ringed Seal also gives birth in pack ice habitat, which is widespread (see Habitat ). Birth lairs are presumed to occur at a much lower density in the pack ice, but this habitat is still used for critical life history functions (see Life cycle and reproduction and Dispersal and migration). Using a reduced range (e.g., landfast ice only) would result in a smaller IAO but it would still be much larger than the threshold of Criteria B for Endangered and Threatened species (>500 km2 and >2 000 km2, respectively).

All GIS-based analyses and calculations were completed using a Canada Albers Equal-Area projection in ArcView 3.3 (ESRI Inc., Redlands, CA) and QGIS 2.16.3.

Search effort

The distribution maps for Ringed Seal were developed based on a shapefile made available by Kelly et al. (2010a). The shapefile includes the global geographic ranges of the five Pusa subspecies, and was created based on an extensive literature review. The range map (Kelly et al. 2010a) was compared to other sources (e.g., Reidman 1990; Jefferson et al. 1993; Hammill 2009) to look for potential errors or omissions. Its accuracy for eastern Canada, along the southern limit, was confirmed through discussion with regional experts (Gosselin pers. comm. 2017; Hammill pers. comm. 2017; Stenson pers. comm. 2017).

Habitat

Habitat requirements

Ringed Seal is a marine species that is adapted to living in close association with sea ice and, as such, is a pagophilic (ice-loving) species. Their presence and density are variable throughout their range, presumably in response to prey availability and distribution (Reeves 1998). Sea ice is used as a platform to raise pups, rest and moult (Frost and Lowry 1981; Kingsley 1990; Reeves 1998).

Because habitat use can change with ice concentration and time of year, this document will summarize information from the open-water and ice-covered seasons. It should be noted that most information is derived from studies of Ringed Seal that occupy near-shore areas and their behaviour may differ from those occupying offshore areas (Finley et al. 1983). Most of the published studies of ice habitat have also been conducted close to shore and may be similarly biased (Reeves 1998).

Open-water season

During the open-water season, Ringed Seal are not constrained in their movements and often travel long distances (see Dispersal and migration ). Travelling individuals utilize a variety of ocean depths, and foraging can be inferred because most satellite telemetry tags used on Ringed Seal also collect dive information (Yurkowski et al. 2016a).

Habitat use is variable among regions, age classes and size classes. Yurkowski et al. (2016a) identified a latitudinal gradient in movement ecology, with seals at higher latitudes spending less time in a resident behavioural state compared to seals at lower latitudes where the ice-free season is longer. In Hudson Bay, Luque et al. (2014) found that both adults and subadults travel more and move through deeper water depths during the open-water season. In Baffin Bay, on the Greenland coast, Born et al. (2004) found that adult seals were more likely to dive deeply than subadult seals. In the North Water region, Teilmann et al. (1999) found that smaller seals used the top 50 m of the water column while larger seals dove deeper, but all the seals they tracked made at least occasional dives to >250 m. Crawford et al. (2012) tracked adult and subadult Ringed Seal off the coast of Alaska and found differences in habitat use between the two groups during all seasons, with subadults occupying areas in deeper water and at a greater distance from the edge of the permanent ice pack in the open-water season (Crawford et al. 2012). More information about diving and movement is available in the Physiology and adaptability and Dispersal and migration sections, respectively.

Ice-Covered season

The ice-covered season imposes different constraints on different segments of the population. Younger animals tend not to be found on landfast ice, either because they are pushed out by breeding-aged territory holders (Stirling 1973; Smith 1987) or because they can save energy reserves by not maintaining breathing holes over the winter (Crawford et al. 2012). In the Beaufort, Chukchi and Bering seas, subadults are found on pack ice or at the ice edge as it grows over the winter and retreats in the spring (Crawford et al. 2012). Ringed Seal also tends to be found on heavier ice than other ice-adapted seals (Simpkins et al. 2003). McLaren (1958b) observed that adult seals made up most, if not all, of the animals harvested on the landfast ice of southwestern Baffin Island and that subadult animals occupied the offshore areas. Subadult Ringed Seal tagged near Resolute, Nunavut, migrated to Baffin Bay (Yurkowski et al. 2016a), but it has also been suggested that the offshore pack ice of Baffin Bay contains more than just subadults and constitutes a separate population of Ringed Seal (Finley et al. 1983).

Sea ice is also used by all +1 age classes for moulting during the spring. While hauled out on the ice, Ringed Seal engages in various antipredator behaviours that include hauling out away from the ice edge (i.e., at the centre of larger ice floes in the pack ice or at cracks in landfast ice), by orienting themselves with their head towards their escape route (ice hole or crack) and by positioning their head to be downwind (Kingsley and Stirling 1991; see more about vigilance behaviours in Physiology and adaptability). Landfast ice, in general, has higher densities of hauled-out seals compared to pack ice (Kingsley et al. 1985). Kingsley et al. (1985) and Stirling et al. (1982) found a preference for basking seals to be hauled out over shallower waters (<150 m and <100 m, respectively) in the Beaufort Sea, although this may be related to a preference for landfast ice.

Breeding habitat

If a critical habitat could be argued for Ringed Seal, it would be the sea ice habitat used for parturition and lactation (Hammill and Smith 1989, 1991; Furgal et al. 1996). In the fall, as the sea ice forms, adult Ringed Seal set up territories in the best habitats (Smith and Stirling 1975). These areas consist of places with good snow coverage and where stable landfast ice will form (McLaren 1958a; Smith and Stirling 1975; Cleator 2001). These tend to be areas where the ice forms pressure ridges, with plates of ice being forced up out of the plane of the water surface. This protruding ice will then catch blowing snow and form drifts on the windward and lee side of the ridge, in which a den or lair can be dug (Smith and Stirling 1975). In a similar situation, the ice in fiords with glaciers can provide habitat as the bergs from the glacier freeze into the ice and likewise collect snow (Lydersen and Ryg 1991). Aboriginal Traditional Knowledge sources and scientific researchers identify a number of den types that serve as areas for resting, suckling, birth and escape (Smith and Stirling 1975, 1978; Cleator 2001; Furgal et al. 2002). For more discussion of lairs, see Physiology and adaptability .

Snow cover has also been identified as important to the formation of drifts for denning and to overall pup production (Smith 1987; Ferguson et al. 2005; Iacozza and Ferguson 2014). Birth lairs tend to be larger, with more snow cover over them, compared to lairs used by rutting males (Lydersen and Gjertz 1986). Ferguson et al. (2005) found that snow depths of less than 32 cm were correlated with reduced recruitment in western Hudson Bay. Hezel et al. (2012) considered 50 cm of accumulated snow in drifts next to pressure ridges to be the minimum requirement for denning, and used a remotely sensed snow cover depth of 20 cm on level ice as a model threshold that would result in an appropriate snow depth for denning in drift areas.

On a broad scale, it has been noted that complex coastlines are especially productive because they have abundant stable ice habitat (McLaren 1958a). However, pack ice has also been identified as breeding habitat in Baffin Bay (Finley et al. 1983), the Barents Sea (Wiig et al. 1999) and the Okhotsk Sea (Fedoseev and Yablokov 1964 in Wiig et al. 1999). These areas may represent a source of many seals. Indeed, Stirling and Øritsland (1995) suggest that in some areas the population of Ringed Seal required to support the estimated Polar Bear population cannot be filled by the estimated productivity of landfast ice habitat alone. This could indicate that suitable breeding habitat can exist where the pack ice is relatively stable and, like landfast ice, accumulates snow drifts suitable for birth lairs. Unfortunately, little research is conducted in these habitats due to the logistical challenges they present.

Habitat trends

Ringed Seal is an ice-adapted species. Therefore, the loss of sea ice is a loss of habitat for this species. They are adapted to seasonal sea ice (which forms and melts annually) and, within that, to a relatively narrow range of sea ice conditions. Throughout most of the Arctic, Ringed Seal recruitment and abundance are related to both ice and snow conditions (Harwood et al. 2000; Ferguson et al. 2005; Harwood et al. 2012b; Iacozza and Ferguson 2014). Extreme heavy ice years or extreme late break-up can have negative demographic effects (Harwood et al. 2012b).

Trends in sea ice

Arctic sea ice has changed significantly in the last 30 years (IPCC 2013). In much of the Ringed Seal’s range, the length of the ice-covered season has declined (Parkinson 2014; Laidre et al. 2015). This has been due to both earlier spring break-up and later fall freeze-up (Parkinson and Cavalieri 2002; Gagnon and Gough 2005; Howell et al. 2009; Galley et al. 2012; Stern and Laidre 2016). There have also been changes in ice types, in the form of a reduction in multi-year ice (ice that lasts for more than one year), as well as a correlated reduction in ice thickness (Kwok et al. 2009; Stroeve et al. 2012; Meier et al. 2014). A shift from multi-year to annual ice in some regions (e.g., Canadian Arctic Archipelago) may improve Ringed Seal habitat, but overall trends in habitat quality and availability are expected to be negative.

Aboriginal Traditional Knowledge holders throughout the species’ range in Canada and adjacent jurisdictions (Alaska, Greenland) have observed changes in sea ice. Observed changes include later freeze-up and earlier break-up (a longer open-water season), thinner ice, a reduction in both multi-year ice and landfast ice, and fewer icebergs and pressure ridges. These trends have been reported from west to east: in Alaska (e.g., Voorhees et al. 2014; Huntington et al. 2016, 2017); the Canadian Beaufort Sea (e.g., Slavik 2013; Joint Secretariat 2015); the central Arctic (e.g., Keith et al. 2005; Keith 2009); Foxe Basin, Hudson Bay, and Hudson Strait (e.g., the Communities of Ivujivik, Puvirnituq and Kangiqsujuaq et al. 2005; Laidler 2006; Ford et al. 2009; Laidler et al. 2009; Shannon and Freeman 2009); Davis Strait and Baffin Bay (e.g., Dowsley 2005, 2007; Kotierk 2010); northern Labrador (York et al. 2015); and West Greenland (e.g., Born et al. 2011).

The abovementioned changes are linked to global atmospheric and oceanic temperatures, which are increasing due to greenhouse gas emissions (IPCC 2013), and they are predicted to continue in the same direction into the foreseeable future (Kelly et al. 2010a). Estimates of an ice-free summer in the Arctic vary, but could be as soon as 2020 to 2050 (Serreze et al. 2007; Overland and Wang 2013). Explicit modelling of trends in sea ice to 2100 were conducted by Kelly et al. (2010a) for the US ESA listing process, with simulations showing trends to earlier spring break-up, later fall freeze-up, and summer retraction of sea ice to core areas, such as the central Canadian Archipelago. They also examined regional differences in sea ice trends and found similar results, albeit with more model uncertainty (Kelly et al. 2010a).

In Svalbard, models indicate that if ice retreats more than 600-700 km from the coast of Svalbard, it will become energetically unprofitable for seals pupping in this area to use that sea ice for foraging (Freitas et al. 2008b). Recent ice loss near Svalbard has shifted summer marginal ice edges over less productive deeper waters, with a resulting increase in energetic costs to seals (Hamilton et al. 2015). Observed shifts in the increased use of terrestrial haul-out sites for resting have been documented coincident with sea ice loss (Lydersen et al. 2017). In the Baltic Sea, loss of sea ice for pupping is predicted to reduce the population to 16% of historical numbers by 2100 (Sundqvist et al. 2012).

Trends in snow cover

Snow cover on sea ice is important for thermal protection and predator avoidance for Ringed Seal pups (Smith and Stirling 1975; Lydersen and Smith 1989; Kelly and Quakenbush 1990; Smith and Lydersen 1991). Ferguson et al. (2005) noted a reduction in snow depth in western Hudson Bay, and Aboriginal Traditional Knowledge holders have also observed reductions in the snow cover needed for birth lairs (e.g., Keith et al. 2005; Joint Secretariat 2015). Although it is predicted that precipitation will increase with a warming climate (Walsh 2008; IPCC 2013), this precipitation must occur at the appropriate air temperature in order to fall as snow on ice, and it is predicted that snow accumulation on ice will decrease (Kelly et al. 2010a). Reduced snow accumulation will reduce the available habitat for building subnivean lairs and will also melt sooner in the spring, leaving Ringed Seal pups exposed to the elements and predators (Kelly et al. 2010a). Hezel et al. (2012) predicted that snow accumulation will be delayed in projected models, resulting in decreases in spring snow depth. Similarly, snow depth is projected to decline in Hudson Bay, with direct effects on Ringed Seal recruitment expected (Iacozza and Ferguson 2014). Ultimately, climate change models predict a similar fate for the Ringed Seal as for Polar Bear: that breeding habitat will not be available in the southern portions of their range because the ice season will be too short (Castro de la Guardia et al. 2013; Hamilton et al. 2014).

Trends in ocean productivity

Arctic ecosystems and species have adapted to the presence of ice and, as a consequence, changes in ice will have broad impacts on the entire ecosystem of which Ringed Seal is a part. Changes that have already been observed in other Arctic species include: mismatches in prey availability (Gaston et al. 2005), northward range expansions of predators (Higdon and Ferguson 2009), and changes in community structure (Grebmeier et al. 2006; Post et al. 2009; Marcoux et al. 2012; also see Threats and limiting factors section).

For further discussion of the impacts of trends described above, particularly climate change, see Threats and limiting factors .

Biology

Information on the biology of Ringed Seal in Canada comes from a combination of research and Aboriginal Traditional Knowledge from all parts of their global range. There is no evidence that the biology differs fundamentally among regions except as it relates to the productivity of the system and the dynamics of the subpopulation.

Life cycle and reproduction

The following section refers primarily to studies of the life cycle of Ringed Seal within their Canadian range unless otherwise indicated. Variations in life history parameters relating to Habitat, Physiology and adaptability and Threats and limiting factors are discussed in corresponding sections.

Single Ringed Seal pups are born between March and May, in a birth lair that has been excavated by their mother, above a breathing hole in a snowdrift (Smith and Stirling 1975; see Habitat section). Pups nurse for 5 to 8 weeks in stable, landfast ice (McLaren 1958a; Smith 1973; Hammill et al. 1991; Lydersen and Hammill 1993a) or as little as 3 in moving pack ice (Burns 1970), before being weaned and abandoned around the time of ice break-up (Hammill and Smith 1991). An earlier weaning period, between mid-April and mid-May, has been observed in lower latitudes such as Hudson Bay, which may ensure an uninterrupted lactation period in an area with earlier spring break-up (Harwood et al. 2000; Chambellant et al. 2012).

Before weaning, pups spend half of their time making short feeding dives under the ice (Lydersen and Hammill 1993b; Furgal et al. 1996; Lydersen 1998). Weights of lactating females can decline by an estimated 32% (Hammill et al. 1991), which is offset by drawing on fat reserves as well as active supplementation via feeding under the ice (Hammill 1987; Kingsley 1990; Kelly and Wartzok 1996).

After weaning their young, female Ringed Seals spend the majority of their time hauled out on the sea ice to moult (Kelly et al. 2010b). For both sexes, the moulting season occurs from late March until July, peaking in June (Frost and Lowry 1981). During this season, individuals haul out onto ice along cracks or leads to bask in the sun (McLaren 1958a; Smith 1973), presumably to raise skin temperature for proper hair regrowth (Feltz and Fay 1966; Boily 1995; Paterson et al. 2012), which is energetically expensive (Boily 1995; see Physiology and adaptability ). The amount of time spent basking increases over the course of the moulting season, and non-breeding seals moult earlier than breeding adults (Vibe 1950).

Following ice break-up, Ringed Seal maximizes energy and reserves by feeding intensively during the open-water season (Young and Ferguson 2013a). Overall, Ringed Seal shows a high degree of diet variability depending on the availability of different prey species in the area. Across their range, Ringed Seal feeds on a wide variety of pelagic and benthic prey. However, at finer geographic scales they tend to focus on 2-4 species (McLaren 1958a; Johnson et al. 1966; Weslawski 1994; Siegstad et al. 1998; Yurkowski et al. 2016c), the most common of which are pelagic schooling fish such as Arctic Cod (Boreogadus saida), as well as amphipods, euphausiids, shrimp and other crustaceans (Chambellant 2010; Cleator 2001).

Diet composition varies by latitude (McLaren 1958a; Yurkowski et al. 2016b,c).  Sand Lance (Ammodytes spp.) and Capelin (Mallotus villosus) dominate the diets of Ringed Seal in the southern range such as western Hudson Bay (Chambellant 2010; Chambellant et al. 2013), southeast Hudson Bay (Breton-Provencher 1979; Young and Ferguson 2013b), Ungava Bay and northern Labrador (McLaren 1958a), whereas Arctic Cod is the main prey item for Ringed Seal in northern areas, such as the western Canadian Arctic (Smith 1987), the high Canadian Arctic (Bradstreet and Finley 1983), northern Foxe Basin, southwest Baffin Island (McLaren 1958a), northern Baffin Island (Holst et al. 2001) and Resolute Bay (Matley et al. 2015; Yurkowski et al. 2016a). Yurkowski et al. (2016b,c) observed latitudinal patterns in diet and attributed them to differences in prey availability.

In studies of Ringed Seal diet, three additional forms of variation have been explored—age class, seasonal and interannual variation—the latter two of which are discussed in the Habitat and Physiology and adaptability sections. Some studies have reported that pups feed more on invertebrates than adults (Lowry et al. 1980; Bradstreet and Finley 1983; Smith 1987; Holst et al. 2001; Crawford et al. 2015), although others have not found a biologically significant difference (McLaren 1958a; Holst et al. 2001; Chambellant et al. 2013). For their first year, pups appear to be limited to feeding in shallow depths due to their size (Kelly and Wartzok 1996).

The sex ratio between male and female pups is 1:1, and this pattern persists into adulthood (McLaren 1958a; Smith 1973; Breton-Provencher 1979; Smith 1987; Holst et al. 1999; Chambellant 2010). Mean age at maturity has been shown to vary with the productivity of the environment (Holst and Stirling 2002; Krafft et al. 2006). In most areas, both sexes reach sexual maturity between 4 and 7 years of age (McLaren 1958a; Mansfield 1967; Tikhomirov 1968; Smith 1973, 1987; Holst et al. 1999; Holst and Stirling 2002), although some female Ringed Seals can reach maturity at three years (Krafft et al. 2006) or as late as 9 years (Kingsley and Byers 1998). Maturity and ovulation are related to body condition, and ovulating females tend to be in better body condition than non-ovulating females (Harwood et al. 2000, 2012b). Although females forage during lactation to support the energetic cost, body condition declines during this period (Lydersen 1995; Lydersen and Kovacs 1999). Nguyen et al. (2017) suggest caution when using ovulation rate as an absolute indicator of reproductive output for Ringed Seal. For example, in Hudson Bay, no relationship was found between ovulation rate, pregnancy and percentage of pups in the fall harvest (Chambellant et al. 2012; Young et al. 2015).

The breeding system of Ringed Seal has not been resolved conclusively. Some believe them to have a weakly polygynous, resource-defence mating system (Smith and Hammill 1981; Kingsley 1990; Yurkowski et al. 2011) while some have suggested a monogamous or mixed breeding system rather than polygyny (Kelly et al. 2010b). Arguments for limited polygyny have been based on several observations: aggressive behaviour and bite wounds on adult and subadult males (Smith and Hammill 1981; Smith 1987; Smith et al. 1991; but see Kelly et al. 2010b; Crawford et al. 2015); segregation between age classes and disparate sex ratios in landfast ice breeding areas (Smith 1987); increased underwater vocalizations during the breeding season (Stirling et al. 1983; but see Richardson et al. 1995); restricted diving (Kelly and Wartzok 1996); restricted movements by males during the breeding season; and scent marking by males (Smith 1987; Hardy et al. 1991; Ryg et al. 1992), which could indicate that they guard the primary breathing hole of one post-parturient female until she is receptive (Kelly et al. 2010b). Kelly et al. (2010b) also argue that the necessity of maintaining breathing holes constrains polygyny in Ringed Seal, and that males may employ mixed strategies, as Hooded Seals (Cystophora cristata) have (Kovacs 1990).

At freeze-up, adults and maturing subadults move into breeding areas and attempt to establish territories, with some showing signs of site fidelity during the winter and spring (McLaren 1958a; Smith and Hammill 1981; Kelly and Quakenbush 1990; Kraftt et al. 2007; Kelly et al. 2010b). Sexually mature adults tend to occupy the prime, stable pack ice habitat suitable for birth lairs (McLaren 1958a; Smith 1973; Smith and Hammill 1981). Some subadults have been observed being driven away from prime breeding areas by adults (Stirling 1973; Smith 1987), and most spend the winter months along the ice edge, leads or polynyas (McLaren 1958a; Stirling et al. 1981; Krafft et al. 2007; Crawford et al. 2012; see more about subadult dispersal in Dispersal and migration).

Peak spermatogenetic activity and maximum testes size occur when males are in rut from March to mid-May (McLaren 1958a; Johnson et al. 1966) and they emit strong-smelling facial secretions from sebaceous and apocrine glands (Smith and Stirling 1975; Hardy et al. 1991). Some believe this scent is used as a territorial marker or an attractant that induces oestrus in females within the territory (Hardy et al. 1991; Ryg et al. 1992). Aboriginal Traditional Knowledge from the Admiralty Inlet area of Nunavut indicates that adult males begin to secrete this odour from shortly after ice consolidation until Ringed Seal basks on top of the ice prior to and during the moult in June (Furgal et al. 2002), which is a longer period than has been reported in the scientific literature in the past (Hardy et al. 1991; Ryg et al. 1992).

Females ovulate towards the end of lactation (Smith 1987), and mating is thought to occur underwater around the time pups are weaned in mid- to late May (Smith 1987; Lydersen 1995). Gestation (typically 10–11 months) is divided into ~2–3 months of delayed implantation and ~8 months of active gestation (McLaren 1958a; Smith 1987; Hammill and Smith 1989), which is longer than for many other pinnipeds. Heavy ice years have been associated with several reproductive declines since the 1970s (Smith 1987; Kingsley and Byers 1998; Harwood et al. 2000, 2012b; Stirling 2002; Nguyen et al. 2017). Light ice years can also negatively impact reproduction (Ferguson et al. 2017; additional details are discussed in Habitat and Threats and limiting factors).

Ringed Seal is relatively long-lived, with a maximum age of 43-45 years being recorded (McLaren 1958a; Lydersen and Gjertz 1986). However, relatively few seals over 20 years of age are observed in the wild (Lydersen and Gjertz 1986; Smith 1987; Holst et al. 1999) and the average age for females is higher than for males (Lydersen and Gjertz 1986). Overall, the average lifespan has been estimated at 15–­­­­20 years (Frost and Lowry 1981) to 25–30 years (Kovacs 2014). Causes of death are discussed in Interspecific interactions and Threats and limiting factors.

The generation time of Ringed Seal, measured based on the average age of parents in the population, is uncertain. There are gaps in knowledge of population demographics, survival rates, relative numbers of adult females of a given age, and the age of the oldest reproducing female. All these factors also vary spatiotemporally (Holst and Stirling 2002; Krafft et al. 2006). Lacking strong empirical data, a precautionary generation time value was estimated using the third calculation method recommended by the IUCN (2013), where:

Generation time = age of first reproduction + z (length of the reproductive period)

When z = 0.5 is used in the absence of empirical data on survivorship and the relative fecundity of young versus old individuals in the population, the resulting estimate = 6 + 0.5 (14) = 13 years, assuming that most seals do not live past 20 (see above). The same estimate is generated using the approach Pianka (1988) suggested to obtain a rough estimate, namely:

Generation time = (age of first reproduction + age at last reproduction) / 2

The value calculated here, 13 years, lies between other estimates of a 18.6-year generation length (Lowry 2016) or 11 years suggested by Smith (1973) and Palo et al. (2001). Kelly et al. (2010a) stated that Ringed Seal has a “long generation time” but did not report any empirical values.

Physiology and adaptability

Ringed Seal is the most widely distributed seal in the Arctic (Allen 1880; Chapskii 1940; King 1983), first adapting to the extremes of the Arctic and then, more recently, to surface predators (Smith and Stirling 1975; Smith 1976; Kingsley 1990; Stirling et al. 1991; Stirling and Øritsland 1995). Having evolved in challenging habitats characterized by long periods of cold temperatures and ice cover, Ringed Seal is uniquely adapted to maintain breathing holes by scratching sea ice with the claws of their fore flippers (Stirling 1974, 1977; Smith and Stirling 1975). They are also adapted to variable food availability as well as predictable periods of positive and negative energy balance (Harington 2008).

Blubber

Ringed Seal has evolved a body type built for Arctic waters. Blubber is distributed consistently over the body, maximizing its availability for insulation, except in its hind section, which is described as “overinsulated” because it has a higher thickness-to-radius ratio. Ryg et al. (1988) described this blubber distribution, reporting that fat is lost most quickly from the overinsulated region during periods of mass loss (e.g., during moult, when seals can lose 30-35% of their blubber stores (Ryg et al. 1990)), thus reducing the negative thermal effects of the fat loss. Ryg et al. (1988) also suggested that this blubber distribution pattern could reflect a compromise between insulation and the streamlining required for water resistance while Ringed Seal is swimming. Heat stress during the hyperphagic period has been suggested as a threat if Ringed Seal becomes overinsulated while water temperatures remain high (Ferguson et al. 2017).

Diving

Three-dimensional tracking models have categorized Ringed Seal dives as either for travel, exploration or foraging/socialization, and they indicate that individuals can switch between these behaviours several times during a dive (Simpkins et al. 2001).

Ringed Seal can dive deeper than 250 m and remain submerged for over 20 min, although dives of less than 10 min long are most common (Lydersen 1991; Kelly and Wartzok 1996; Teilmann et al. 1999; Gjertz et al. 2000; Born et al. 2004; Crawford et al. 2019). Diving capacity varies by body mass, with larger individuals being capable of diving deeper and longer (Kelly and Wartzok 1996; Kelly 1997; Teilmann et al. 1999; Kunnasranta et al. 2002). Diving behaviour also differs by sex (Kelly and Wartzok 1996; Teilmann et al. 1999, Harwood et al. 2015). In winter, females make more dives that are deeper and longer lasting compared to males and subadults, presumably to meet energetic demands of upcoming pupping and nursing (Harwood et al. 2015).

Ringed Seal dive mostly during the day in late summer, fall and winter, and dive mostly at night during the spring to early summer breeding and moulting periods (Kelly and Quakenbush 1990; Lydersen 1991; Teilmann et al. 1999; Kunnasranta et al. 2002; Carlens et al. 2006; Kelly et al. 2010b). In order to dive and feed throughout the year, including periods of darkness (Johnson et al. 1966), Ringed Seal can navigate in the absence of light (Hyvärinen 1989; Wartzok et al. 1992). Captive experiments indicate that they largely use vision to locate breathing holes from under the ice, followed by auditory and vibrissal (touch via whiskers) senses for short-range navigation (Elsner et al. 1989).

Whiskers (vibrissae) appear to be important for spatial adjustment in diving mammals lacking sonar systems, and seals have a high number of nerve fibres penetrating each of their vibrissa follicles relative to other mammals. Hyvärinen and Katajisto (1984) hypothesized that this enables them to 1) sustain sensory functions in cold water (with glycogen serving as an energy source in anaerobic diving conditions) and 2) hunt by sensing turbulent wakes from their prey (Beem and Triantafyllou 2015).

Lairs

One evolutionary trade-off of having a blubber-rich body streamlined for diving is that it makes Ringed Seal less mobile on hard surfaces, making them more vulnerable to surface predators. Smith et al. (1991) hypothesized that these two selective pressures forced Ringed Seal into a different evolutionary strategy than its larger Antarctic counterpart, the Weddell Seal (Leptonychotes weddellii), which pups on the ice. Ringed Seal builds subnivean (below the snow) lairs on the ice so the pups are protected.

Subnivean lairs are generally of two types—birth (or birthing) lairs and resting (or haul-out) lairs—and are built in complexes that allow Ringed Seal to escape predators (Smith and Stirling 1975; see more about lairs in Habitat). Birth lairs provide both physical and thermal protections that are important for the survival of neonates. Although pups are protected from dry cold by their natal lanugo (Øritsland and Ronald 1973, 1978; see Morphological description ), they are prone to irreversible hypothermia when wet and exposed to the elements (Smith et al. 1991). Thus, they rely on regaining thermoneutrality within their insulating birth lairs, which can be 15–27˚ C warmer than ambient temperatures (Kelly and Quakenbush 1990; Smith et al. 1991).

Although most occurrences of pups entering the water are feeding bouts, they can be forced to submerge by approaching predators, in which case the presence of a complex of alternative lairs (Smith and Stirling 1975; Smith and Stirling 1978; Smith and Hammill 1981) becomes important. The relatively low success rate of Polar Bear predation attempts at lairs (Smith 1980; Hammill and Smith 1990, 1991) attests to the efficiency of the birth lair complex at protecting Ringed Seal from bear predation. Resting lairs are assumed to provide subadults and adults with similar protections, although few studies have been conducted on the mechanisms involved (Taugbøl 1984; Smith et al. 1991). One study (Kelly and Quakenbush 1990) suggested that complexes of closely spaced lairs are the work of multiple seals that accrue a “predator swamping” advantage in areas of heavy predation. However, it is also possible that they provide other advantages in this poorly understood social system.

Vocalizations

Several studies have analyzed vocalizations of wild Ringed Seal in the Canadian Arctic (Stirling 1973; Smith and Stirling 1978; Stirling et al. 1983; Calvert and Stirling 1985; Jones et al. 2014). Described call types include yelps, barks, growls and woofs, most of which are less than 0.5 s long. Little interannual or geographic variation has been found, but seasonal differences have been detected, with fewer calls occurring during open-water periods (Jones et al. 2014).

Ringed Seal has a reduced vocal repertoire, quiet volume and lack of geographic variation in acoustic behaviour that is consistent with the hypothesis that there is strong selective pressure to avoid detection under ice (Stirling 1973; Stirling et al. 1983; Stirling and Thomas 2003), as is the observation that the range of best hearing in Ringed Seal is over three octaves above their upper limit of dominant vocal energy (Sills et al. 2015). Ringed Seal also likely relies, to some degree, on acoustic cues for detecting prey, navigating through Arctic waters and avoiding predators—particularly in a lair, where approaching predators cannot be detected by sight (Schusterman et al. 2000).

Parental care

Ringed Seal pups grow relatively slowly compared to other northern phocids, and have a relatively long lactation period, which requires a significant time and energetic investment from females (McLaren 1958a; Smith 1987; Hammill et al. 1991). However, this appears to be a better adaptation than the alternate strategy, employed by other species, of assuming the high energetic costs of building fat reserves (Smith et al. 1991). Females also appear to actively supplement any weight lost during lactation by feeding beneath the ice (Hammill 1987; Hammill et al. 1991; Smith et al. 1991).

Vigilance

Although comprehensive behavioural studies are problematic for a species that spends the majority of its time in subnivean lairs or in water, Ringed Seal appears to invest heavily in vigilance behaviours while hauled out on ice, scanning their surroundings before emerging from the water, re-entering the water then re-emerging several times before settling on the ice and lifting their heads periodically while basking (Smith and Hammill 1981). They appear to use sight, smell and hearing to detect potential threats. Presumably, this is an important adaptation under selection pressure from surface predators (Stirling 1977; Smith and Hammill 1981; predators are also discussed in the Interspecific interactions). Vigilance behaviours vary significantly among individuals, which could be further evidence for a co-evolutionary strategy given that predators could increase their success based on consistent patterns (Stirling 1974; Smith and Hammill 1981). Additional information about vigilance behaviour is presented in Habitat.

Dispersal and migration

Ringed Seal is distributed on a pan-Arctic scale and tracking studies have revealed seasonal and latitudinal differences in dispersal and migration patterns. Although movement can be limited during the winter, likely in relation to sea ice conditions, some subadults and adults migrate long distances during the summer months when sea ice extent is minimal (Kelly and Quakenbush 1990; Teilmann et al. 1999; Gjertz et al. 2000; Born et al. 2004; Harwood et al. 2007, 2012a, 2015; Freitas et al. 2008a; Kelly et al. 2010b; Crawford et al. 2012; Yurkowski et al. 2016a).

Because no studies have followed individual seals for multiple years, there are only snapshots available to characterize home range size. During the ice-covered season home ranges tend to be smaller, when ice limits movement, and more so when territories are being held in landfast ice. At the same time of year, home ranges can be much larger when animals are in mobile ice or near polynas. During break-up and the open-water season, and/or for juveniles and subadults, home ranges can be broad. Several studies have recorded adults and subadults moving extensively (Smith 1987; Heide-Jørgensen et al. 1992a; Kapel et al. 1998; Gjertz et al. 2000; Freitas et al. 2008a; Kelly et al. 2010b; Crawford et al. 2012; Luque et al. 2014; Yurkowski et al. 2016b).

Home range sizes of individuals can vary widely but are generally smaller for adults compared to sub-adults (Luque et al. 2014). Home ranges of 10,300-18,500 km2 have been recorded in the North Water area (Teilmann et al. 1999; Born et al. 2004), and 90% volume contours averaged 21,649 km2 for adult males, 76,658 km2 for adult females and 122,854 km2 for subadults in the Prince Albert Sound and eastern Amundsen Gulf regions, compared to winter ranges, which were on average 15% smaller (Harwood et al. 2015). Similarly, although open-water ranges were smaller for Ringed Seal in the Canadian Beaufort Sea (<1-13.9 km2 for males and <1-27.9 km2 for females), and were possibly underestimated, some individuals moved up to 1,800 km from their winter/spring home ranges in summer and then returned to the same 1–2 km2 sites in the winter (Kelly et al. 2010b).

There is growing evidence that adults are philopatric, returning annually to the same wintering and breeding sites in the landfast ice in the fall (Smith and Hammill 1981; Kelly et al. 2010b), possibly following a similar pattern to their Antarctic counterparts, Weddell Seals, whose site fidelity increases with age and to sites where breeding has been successful (Cameron et al. 2007).

When adults start to establish territories in prime breeding areas prior to freeze-up, some subadults embark on long-distance migrations (Smith 1987; Heide-Jørgensen et al. 1992a; Teilmann et al. 1999; Freitas et al. 2008a; Harwood et al. 2012a). Some travel thousands of kilometres to areas of high prey abundance (Kapel et al. 1998; Freitas et al. 2008a; Kelly et al. 2010b; Crawford et al. 2012; Harwood et al. 2012a), likely as an adaptation to reduce competition with adults for resources (McLaren 1958a; Smith and Hammill 1981; Smith 1987; Hammill and Smith 1989; Freitas et al. 2008a; Crawford et al. 2012). In other areas, their migrations have been linked to advancing and retreating ice (e.g., Crawford et al. 2012).

While migrating, subadult travel rates vary. Some of the highest rates (0.9 m/s) have been recorded in the western Canadian Arctic, where travelling distances of 2,138 km between the Canadian Beaufort Sea and Chukchi Sea have been recorded (Harwood et al. 2012b). These individuals travelled within 100 km of shore, over the continental shelf or slope, and they moved through three international jurisdictions.

Interspecific interactions

Predators

Polar Bear, Arctic Fox (Vulpes lagopus) and humans are Ringed Seal’s most significant predators. Insights into these predator-prey dynamics in Canada have come from scientific studies, as well as Aboriginal Traditional Knowledge studies such as Cleator (2001), Furgal et al. (2002), Keith et al. (2005) and Joint Secretariat (2015). Human uses of Ringed Seal, including hunting, are discussed in Special significance and Threats and limiting factors. Other predators include Walrus (Odobenus rosmarus), Greenland Shark (Somniosus microcephalus), Killer Whale (Orcinus orca), and occasionally Common Raven (Corvus corax), gulls (family Laridae), Red Fox (Vulpes vulpes), Gray Wolf (Canis lupus) and Wolverine (Gulo gulo) (Kingsley 1990; Reeves 1998; Ridoux et al. 1998; Kelly et al. 2010a; Lowry 2016).

The Polar Bear’s diet mostly comprises Ringed Seal and Bearded Seal (Erignathus barbatus), with some regional and temporal variation (Stirling and Archibald 1977; Smith 1980; Stirling and Øritsland 1995; Derocher et al. 2002, 2004; Thiemann et al. 2008; Galicia et al. 2016). When the Ringed Seal pupping season begins in late spring, Polar Bear enters a period of intense feeding that continues into early summer to replenish depleted fat reserves (Stirling and McEwan 1975; Stirling and Archibald 1977; Smith 1980; Ramsay and Stirling 1988). They primarily kill newborn pups, by breaking through the birth lair roof, and will attempt to catch the mother seal when she returns for her pup (Stirling and McEwan 1975; Smith 1980; Kelly et al. 2010a; Joint Secretariat 2015). Polar Bear predation increases significantly when pups are prematurely exposed as a consequence of unseasonably warm conditions or when snow depths decrease (Hammill and Smith 1991).

Hunting bears will usually open more than one birth lair in their attempt to kill a seal. Interannual variations in snow conditions may affect the bear’s ability to detect and break into lairs (Ramsay and Stirling 1988), and pups in thin-roofed lairs are more vulnerable to predators than those in thick-roofed lairs (Smith and Stirling 1975; Hammill and Smith 1991; Furgal et al. 1996; Joint Secretariat 2015). Polar Bear has been observed bypassing non-birth subnivean lairs occupied by adults, and they appear to selectively avoid lairs of rutting males (Smith 1980). Smith (1980) suggested that the strong odour associated with mature males made the meat less palatable.

Polar Bear also stalks seals lying on the ice or at their breathing holes (Kumlien 1879; Freuchen 1935), particularly during the late-spring / early-summer moult when bears are still accumulating fat reserves to last through the ice-free period. They also hunt Ringed Seal in the winter, at which time they are most successful in ice-edge and shear-zone areas inhabited by subadults and less successful at catching breeding adults in the landfast ice (Kingsley 1990). There are accounts of Polar Bear preying on Ringed Seal while swimming (Furnell and Oolooyuk 1980), but these are rare.

Although not to the same degree as Polar Bear, the Arctic Fox is also an important predator of Ringed Seal (Smith et al. 1991). Foxes kill newborn seal pups by digging into their birth lairs (Kumlien 1879; Degerbøl and Freuchen 1935; Smith 1976), but only appear capable of killing newborn pups (Smith et al. 1991). Predation on a Ringed Seal pup by a Red Fox has also been reported (Andriashek and Spencer 1989).

Atlantic (Odobenus rosmarus rosmarus) and Pacific (O. r. divergens) Walrus prey on Ringed Seal (Vibe 1950; Mansfield 1958; Fay 1960; Lowry and Fay 1984). Most seal-eating by Pacific Walruses is predation, rather than scavenging (Lowry and Fay 1984), and the presence of Atlantic Walruses tends to drive Ringed Seal away from an area (Reeves 1998).

Greenland Shark is common throughout much of the Arctic, and Ringed Seal may comprise a significant portion of their diet (Fisk et al. 2002; McMeans et al. 2010; Leclerc et al. 2012), although the overall frequency of predation by this species is unknown (Kelly et al. 2010a).

Killer Whale prey on Ringed Seal in open water, along ice margins or in areas with low ice concentration, but the whales are limited by their inability to penetrate far into pack ice (Kelly et al. 2010a).

Other predators of Ringed Seal pups include Wolves, dogs, Wolverine and Common Raven (Kumlien 1879; Burns 1970; Lydersen and Smith 1989; Kingsley 1990; Burns et al. 1998; Reeves 1998). Smith et al. (1991) suggested that predation by Glaucous Gull (Larus hyperboreus) may be one of the important factors limiting the southern range of Ringed Seal. Predation on newborn pups by surface predators other than Polar Bear and Arctic Fox is typically prevented by the pups’ concealment in lairs (see Physiology and adaptability , and discussion of the implications of climate change in Threats and limiting factors).

Non-predators

Although Ringed Seal occupies areas of sea ice that are impenetrable by other Arctic species in the winter, they encounter a wide range of species during the open-water season and in areas of pack ice. Where Ringed Seal diets overlap with those of these species, competition may be a factor affecting their distribution and abundance in some circumstances (Kovacs 2014).

Potentially competing species include sea birds, fishes and other marine mammals, including other pinnipeds such as Atlantic Walrus, Bearded Seal, Harp Seal (Pagophilus groenlandicus), Harbour Seal (Phoca vitulina) and Hooded Seal, although few have explored these competitive relationships. Wathne et al. (2000) found 100% niche overlap in the diets of Ringed Seal and Harp Seal in the Barents Sea; however, they also found niche separation, with Harp Seal preying on larger fish than Ringed Seal. Harp Seal migrates into the Arctic during the summer and could be a significant seasonal competitor. There is some indication that Harbour Seal is increasing in Hudson Bay (Florko et al. 2018) and has been shown to have some overlap in diet (Young et al. 2010).

Ringed Seal ranges also overlap with those of Arctic cetaceans such as Beluga Whale (Delphinapterus leucas), Narwhal (Monodon monoceros) and Bowhead Whale (Balaena mysticetus). Ringed Seal favours some of the same geographic areas that Bowhead Whale and Beluga Whale use for feeding during late summer, presumably because they are highly productive areas (Harwood 1989; Harwood and Stirling 1992; Harwood et al. 2015). This overlap may also lead to competition for food resources, especially between Ringed Seal and Beluga (Yurkowski et al. 2016b).

Population sizes and trends

Sampling effort and methods

A variety of techniques have been used to survey Ringed Seal, across multiple spatial scales, including ship surveys (e.g., McLaren 1958b,1962; Diemer et al. 2011), crewed aerial surveys of seals and seal holes (and with various detection methods including visual, photographic and infra-red; e.g., Burns and Harbo 1972; Stirling et al. 1982; Lunn et al. 1997; Chambellant et al. 2012; Young et al. 2015), and on-ice searches for holes or lairs using trained detection dogs (Smith and Stirling 1978; Hammill and Smith 1990; Williams et al. 2006).

Most available abundance or density estimates come from aerial surveys, which are usually conducted during the spring basking period, when the greatest numbers of seals are expected to be hauled out to moult. The number of seals on the ice is sometimes multiplied by a correction factor to estimate population size, or the hauled-out numbers are used as a population index. Environmental conditions can influence haul-out patterns, and the timing of annual snow and ice melt varies widely from one year to another (reviewed by Kelly et al. 2010a). Unless surveys are designed to coincide with similar ice and weather conditions, comparisons between years can be erroneous, even if surveys were conducted during the same time of year (Kelly et al. 2010a).

Abundance and trends in Ringed Seal populations are difficult to accurately assess due to factors such as the large extent and remoteness of their range, the variable and constantly changing nature of their sea-ice habitat, seasonal and interannual movements and time spent under water/ice, all of which make surveys expensive and logistically challenging (Kelly et al. 2010a). There has also been limited international cooperation to conduct large-scale surveys across political boundaries (Kelly et al. 2010a). That said, large scale collaborative surveys for Arctic seals have occurred between US and Russian scientists in recent years (Conn et al. 2014; Muto et al. 2017). Indigenous harvesters also note that it is hard to monitor long-term changes in the abundance of species like Ringed Seal because they are highly mobile and go through cycles in terms of their local abundance (e.g., Berger 1976; Slavik 2013; Joint Secretariat 2015).

Abundance

Global population estimates

Estimates of global abundance range from 2.5 million (Miyazaki 2002) to 6-7 million (Stirling and Calvert 1979). Reeves (1998) suggested a world population of no less than a few million animals. Hammill (2009) estimated a “very crude” global population size of the Arctic subspecies to be between 2.8 and 5.1 million seals.

In their assessment of global status of the subspecies, Kelly et al. (2010a) divided the range into four regions: Greenland Sea and Baffin Bay; Hudson Bay; Beaufort and Chukchi Seas; and the White, Barents and Kara Seas (a reflection of the geographical groupings of published research studies and not any population structure). They estimated a total population of 2,060,400 individuals, which was conservative because some estimates were not corrected for seals in the water (basking population only) and the full subspecies distribution was not included because data were not available for parts of the Russian Arctic coast and the Canadian Arctic Archipelago.

A recent review compiled regional estimates from a large portion of the hispida subspecies’ range, totalling about 2.9 million individuals (Laidre et al. 2015), which was used by IUCN in 2016 to estimate the global population of mature individuals to be 1,450,000 animals (Boveng 2016a). An accurate worldwide population estimate is made difficult by the fact that large areas of the species’ range have not been surveyed, and by uncertainty regarding the relationship between observed numbers and actual population sizes (Frost and Lowry 1981; Reeves 1998; Kelly et al. 2010a).

Canadian (and Adjacent Areas) Population Estimates

The total Ringed Seal population in Canada and adjacent waters (West Greenland, Alaska and Russia) is estimated as 2.3 million seals, with low confidence, because some areas are lacking information (Table 1). Some areas of the Canadian range have no comprehensive estimates. For example, there have been limited surveys in the Canadian Arctic Archipelago (e.g., Kingsley et al. 1985; Kelly et al. 2010a) and there is insufficient information to estimate regional abundance.

Table 1. Estimated size of Ringed Seal population in Canada and adjacent waters. Portions of the Canadian range are included based on data availability.
Region (Jurisdiction(s)) Estimate Source(s) Comments

Baffin Bay (Canada, Greenland)

787,000

Finley et al. 1983

Aerial surveys in 1979. Considered by both Kelly et al. (2010a) and Laidre et al. (2015) to be best available estimate. Trend unknown, possibly stable (based on Greenland harvests). Alternate model-based estimates (Polar Bear energetic model and sea ice and density models) suggested Baffin Bay population size of 1,200,000 seals (Kingsley 1998).

Hudson Bay, James Bay (Canada)

516,000

Smith (1975)

1974 aerial surveys, densities extrapolated to entire region based on the distribution of ice types. Includes 61,000 seals in James Bay (considered an underestimate due to the advanced break-up of the ice at time of the survey and subsequent low density estimates). Laidre et al. (2015) used this estimate in their assessment, with an unknown trend. Recent surveys suggest that abundance (density) follows a cyclical pattern (Young et al. 2015). This estimate does not include Foxe Basin.

Beaufort and Chukchi Seas (Canada, USA, Russian Federation)

1,000,000

Frost et al. (2004); Bengtson et al. (2005)

Kelly et al. (2010a) (and Laidre et al. 2015) considered 1,000,000 seals a “reasonable estimate” for the total population, including at least 50,000 in Canadian waters, with an unknown trend.

Total

2,303,000

Not applicable

Negatively biased - excludes areas of Ringed Seal range in Canada, e.g., central Arctic Archipelago, Labrador coast.

Numerous surveys have been conducted in relatively small study areas, but it is difficult to extrapolate to regional-scale estimates. There are also no estimates available for Ringed Seal abundance along the Labrador coast (although local Inuit reported that the population was increasing in the mid-1990s, chiefly due to a decline in harvesting, Williamson 1997). It must also be noted that much of the information used to generate the total population estimate is dated; however, the sources used, and alternate sources and estimates, are discussed below for each region. A total population of 2.3 million Ringed Seal translates to 1,150,000 mature individuals, assuming 50% adults as per the IUCN assessment (Boveng 2016a).

Baffin bay region population estimates

Surveys in 1979 covered northeast Baffin Island landfast ice and Baffin Bay pack ice habitats (Finley et al. 1983). More than 67,000 seals were estimated for the landfast ice areas, with another 417,000 in the Baffin Bay pack ice. The estimate was corrected to a total of 787,000 seals in Baffin Bay (Canada and Greenland) once seals missed during the surveys were accounted for (Finley et al. 1983). Miller et al. (1982) reported on surveys of West Greenland landfast ice that were also conducted in 1979, estimating 97,800 Ringed Seal for that region of eastern Baffin Bay. They also estimated an additional 15,500 seals in the landfast ice along the east coast of Devon Island and north to 80° latitude (Miller et al. 1982).

Kelly et al. (2010a) used the estimate of 787,000 by Finley (1983) as the only comprehensive estimate available for the region, and they considered the relative consistency of Greenland harvests over time (Kapel and Rosing-Asvid 1996) to provide some confidence that the population has not significantly changed. Laidre et al. (2015) also used the 1979 estimate of 787,000 seals in Baffin Bay (Finley et al. 1983) in their assessment but considered the trend to be unknown.

Kingsley (1998) estimated the size of the Baffin Bay Ringed Seal population using two methods, one based on Polar Bear energetic models and another using published density data and estimates of ice areas. He used linked models of Polar Bear growth and energy needs, Polar Bear population structure and Ringed Seal energetic yield to estimate that a standing population of 1.2 million Ringed Seal would be needed to sustain Polar Bear predation levels and a human harvest of 100,000 seals per year (and assuming that the entire population is accessible to harvest/predation; the standing population would be higher if it was partly inaccessible). The estimate based on sea ice type and availability and estimated Ringed Seal density was 697,200 hauled out (“sightable”) seals, which would yield a similar population estimate as the Polar Bear predation model (1.2 million seals) (Kingsley 1998).

Hudson Bay region population estimates

The earliest population estimate for Ringed Seal in this region was 218,300 in the 1950s, based on density estimates in different types of landfast ice and the amounts of those ice types available (McLaren 1958b). In 1974, Smith (1975) conducted aerial surveys throughout much of western Hudson Bay. Flight tracks were categorized by ice type, and survey densities were extrapolated to the entire region based on the distribution of ice types, resulting in an estimate (rounded to the nearest 1,000) of 455,000 Ringed Seal in Hudson Bay. This estimate was much larger than the 1950s estimate, but Smith (1975) included pack ice habitats in his calculations, which McLaren (1958b) did not. Smith (1975) estimated an additional 61,000 seals in James Bay, and considered this to probably be an underestimate due to the advanced break-up of the ice at the time of the survey and subsequent low density estimates. Laidre et al. (2015) used this combined estimate of 516,000 seals in Hudson and James bays in 1974 (Smith 1975) in their assessment, with an unknown trend.

More recent aerial survey estimates are available, but they are limited to western Hudson Bay and have generally reported on hauled-out abundance (a population index, and not a population estimate). Young et al. (2015) report on data from systematic aerial strip transect surveys flown in western Hudson Bay in late May to early June of 1995-1997, 1999, 2000, 2007-2010 and 2013 (also see Lunn et al. (1997) and Chambellant et al. (2012)). Each survey attempted to replicate the same 10 transects from the Hudson Bay shoreline in the west to the 89° W longitude line in the east, and from Churchill, Manitoba in the south to Arviat, Nunavut in the north—a study area originally designed by Lunn et al. (1997) to cover the winter and spring hunting habitat of the Western Hudson Bay Polar Bear population (Stirling and Derocher 1993). The density of hauled out Ringed Seal ranged from 1.22 seals/km2 in 1995 (population index = 104,162 seals) to 0.20 seals/km2 in 2013 (population index = 16,746 seals). Density estimates varied significantly and followed a cyclical pattern with the exception of 2013 (Young et al. 2015; Ferguson et al. 2017). There was an overall negative trend over time, but a multiple linear regression weighted by survey effort showed no significant trend in density. The authors suggested that the low density estimate in 2013 might indicate that population changes unrelated to a natural cycle are taking place (Young et al. 2015).

Ferguson et al. (2017) compared environmental patterns to Ringed Seal reproduction, body condition, recruitment and stress in Hudson Bay from 2003 to 2013, linking longer open-water periods to decreased body condition and increased stress (cortisol). During this period, the year 2010 was the earliest spring break-up and the latest ice formation in Hudson Bay, which coincided with high cortisol levels and declines in reproductive rates. Ferguson et al. (2017) concluded that while negative demographic responses were gradually occurring with sea ice declines in Hudson Bay, an episodic environmental event had likely played a significant role in a punctuated decline in Ringed Seal abundance.

Ringed Seal is also found throughout Foxe Basin, north of Hudson Bay. McLaren (1958b) also estimated the number of seals in this region (ca. 100,000 seals), using the same methods described above, but no recent data are available except some limited industry-sponsored surveys (e.g., BIMC 2012). No Foxe Basin abundance estimates are reported here.

Beaufort and chukchi seas population estimates

Most population assessments in the Beaufort and Chukchi Seas are confined to Canadian and U.S. waters, and there are few data for animals in the Russian sector (Kelly et al. 2010a). Surveys were conducted in 2012 and 2013 but have not been fully analyzed (Conn et al. 2014; Muto et al. 2017). Based on aerial surveys in 1985-1987, Frost (1985) derived estimates of 250,000 Ringed Seal in the Alaskan landfast ice of the Chukchi and Beaufort Seas, with a total of 1-1.5 million when seals in pack ice habitats were included. The most recent Bering Sea estimate is 170,000 seals (Conn et al. 2014).

In western Canadian Arctic waters, surveys in some areas were first flown in the early 1970s (Smith 1987), and extensive surveys were flown in the early 1980s (Kingsley and Lunn 1983). The 1981 and 1982 surveys of the eastern Beaufort and Amundsen Gulf regions were the most comprehensive. Kingsley and Lunn (1983) estimated the number of hauled-out Ringed Seal in the eastern Beaufort at 5,400-5,500 and the number in Amundsen Gulf as 30,900 in 1981 and 70,500 in 1982. This wide interannual variability is similar to other regions (e.g., western Hudson Bay; Lunn et al. 1997) and highlights the need for a better understanding of the relationships between Ringed Seal behaviour, environmental conditions and survey methods (Kelly et al. 2010a). Surveys in the southern Canadian Beaufort Sea have revealed decadal-scale fluctuations in Ringed Seal abundance (Stirling et al. 1977, 1982; Smith 1987; Harwood and Stirling 1992), and it is suggested that these changes mainly relate to environmental variation, particularly changes in the sea ice regime (Stirling et al. 1977; Smith 1987).

Kelly et al. (2010a) summarized the available data (e.g., Frost et al. 2004; Bengtson et al. 2005) for the Beaufort and Chukchi Seas in their status assessment, and they considered a “reasonable estimate” for the total population to be 1,000,000 seals (not assigned to any particular year(s)), including at least 50,000 in Canadian waters (eastern Beaufort Sea and Amundsen Gulf). Laidre et al. (2015) used the Kelly et al. (2010a) estimate in their summary, with an unknown population trend. Hammill (2009) suggested total of 1-1.5 million seals for Alaska.

Fluctuations and trends

There are no data available for a wide-ranging population assessment, and there is insufficient information on trends at the level of the designatable unit (i.e., the entire range in Canada and adjacent areas) and limited data at the regional (or smaller) level. This adds substantial uncertainty to any status assessment. For example, Kelly et al. (2010a) assumed that seal numbers in Baffin Bay were stable because Greenland harvests have remained relatively consistent over time, but this assumption has not been tested. Surveys for Ringed Seal abundance generally occur at smaller spatial scales than the regions discussed above, and it is difficult to extrapolate results to larger regions (see Abundance ). Surveys in the southern Beaufort Sea (Stirling et al. 1977, 1982; Smith 1987; Harwood and Stirling 1992) and western Hudson Bay (Young et al. 2015) have revealed decadal-scale fluctuations in Ringed Seal abundance that are thought to be related to environmental variation, particularly changes in the sea ice regime (Stirling et al. 1977; Smith 1987; Ferguson et al. 2017). In western Hudson Bay, there has been an overall negative trend in density over time, but the decline is not statistically significant.

Some harvesters believe seals are travelling to places where there are better ice conditions, but that their numbers have not declined (e.g., Slavik 2013). Hunters in Alaska have described some local reductions in seal abundance due to changing ice conditions, but they note that Ringed Seal remains abundant and that the overall population is stable (Voorhees et al. 2014; Huntington et al. 2016, 2017). The degree of interchange between these seals and those in western Canadian waters is unknown.

Inuit in the central Arctic community of Gjoa Haven, Nunavut have indicated that the population of Ringed Seal in the area is healthy (Keith et al. 2005; Government of Nunavut 2012). In Taloyoak, Nunavut, hunter observations have been variable and contradictory, with some saying Ringed Seal numbers have decreased over time and others suggesting they have increased over time (Government of Nunavut 2015). Hunters in Grise Fiord, Nunavut have observed a decrease in the number of Ringed Seal in their area (Government of Nunavut 2013). Baffin Bay harvesters who were interviewed about Polar Bear provided little information on Ringed Seal abundance, with one Qikiqtarjuaq, Nunavut interviewee saying that changing ice conditions were making it harder for bears to find seals, but noting that the seal population was unchanged (Dowsley 2005, 2007). Pangnirtung, Nunavut Inuit have reported seeing fewer Ringed Seal in Cumberland Sound, noting a suspicion that this is related to increased human activities and noise pollution in addition to increased predation from a growing Polar Bear population (Government of Nunavut 2014). Some Aboriginal Traditional Knowledge holders in southern Davis Strait reported that seal numbers were low from 2005 to 2010, and that a larger proportion of seals were adults, possibly due to climate change impacts on pups (Kotierk 2010). Hunters in Chesterfield Inlet, Nunavut (western Hudson Bay) have reported that Ringed Seal is decreasing in number (Government of Nunavut 2010). Overall, there are reports of declines in some areas, but information is not available across the entire species range. It is also unknown whether local changes represent declines or distribution shifts with sea ice changes (Slavik 2013).

Ringed Seal recruitment and abundance are related to both ice and snow conditions (Harwood et al. 2000, 2012b; Ferguson et al. 2005; Iacozza and Ferguson 2014; see Habitat ). Environmental extremes, including both heavy-ice years and years with early break-up, can have negative demographic effects (Harwood et al. 2012b; Ferguson et al. 2017). Arctic sea ice has changed significantly in the last 30 years and there has been an increase in the length of the open-water season, due to both earlier spring break-up and later fall freeze-up (Parkinson and Cavalieri 2002; Gagnon and Gough 2005; Parkinson 2014; Laidre et al. 2015). Snow cover on sea ice is a critical component of pupping habitat (Smith and Stirling 1975; Lydersen and Smith 1989; Kelly and Quakenbush 1990; Smith and Lydersen 1991). Spring snow depth has been declining in western Hudson Bay, with negative impacts on Ringed Seal (Ferguson et al. 2005). Models predict continued declines in spring snow depth, with direct effects on Ringed Seal recruitment (Hezel et al. 2012; Iacozza and Ferguson 2014).

Rescue effect

Ringed Seal has a high dispersal ability (see Dispersal and migration ), and genetic analysis has not identified major constrictions to gene flow across their circumpolar range (see Population spatial structure and variability ). As such, the Canadian Ringed Seal population is fully connected to Ringed Seal in other Arctic regions (e.g., western Greenland/ eastern Baffin Bay, Alaskan and Russian Beaufort/Chukchi Seas) that could provide immigrants adapted to live in Canadian waters.

Threats and limiting factors

Threats

Direct threats faced by Ringed Seal assessed in this report were organized and evaluated based on the IUCN-CMP (World Conservation Union-Conservation Measures Partnership) unified threats classification system (Master et al. 2012). Threats were defined as the proximate activities or processes that directly and negatively impact Ringed Seal. These were assessed for the one DU, with results on the impact, scope, severity, and timing presented in tabular form in Appendix 1.

The overall calculated and assigned threat impact is High to Low. The greatest potential anthropogenic threat to Ringed Seal is projected habitat loss due to climate change. The other threats of Energy Production & Mining, Transportation & Service Corridors, and Biological Resource Use were considered negligible.

Climate change & severe weather [iucn threats #11.1 – habitat shifting & alteration] – high to low

Although some benefits (e.g., shifts from multi-year to annual ice in the Canadian Arctic Archipelago) may occur in the short-term and in some areas, loss of habitat due to climate change is a major threat in the medium (next three generations) to long term for Ringed Seal. Estimates of the time until an ice-free summer occurs in the Arctic vary, but this could occur as early as 2020-2050 (Serreze et al. 2007; Overland and Wang 2013) and significant ice reductions in southern areas of the range could occur much sooner (Castro de la Guardia et al. 2013). A study on the demography of Ringed Seal in Amundsen Gulf and Prince Albert Sound projected declines in Ringed Seal population size in all but the most optimistic climate change scenarios (Reimer et al. 2019).

Loss in snow cover is expected to increase susceptibility of Ringed Seal to predation (NOAA 2012). Loss of sea ice could have direct effects on Ringed Seal populations by reducing pup survival, increasing the energetic costs of moulting and reducing haul-out sites important for resting (see Habitat ). Where sea ice loss causes the ice to retreat over deep, unproductive waters, Ringed Seal travels farther, dives longer and spends less time hauled out on ice—suggesting that they are expending more energy to forage than in the past (Hamilton et al. 2015). Indirect effects include shifts in ecosystem composition and function (see Habitat ), access by novel predators and competitors (see Interspecific interactions ) and increased anthropogenic activity.

Inuvialuit harvesters indicate that Ringed Seal needs the type of environmental conditions that are good for ice algae accumulation, because Arctic cod feed on the algae and seals eat the cod (Joint Secretariat 2015). New scientific research supports these observations and shows that ice algae are a critical component of the Arctic marine food web through all trophic levels (Brown et al. 2018). Therefore, not only will declines in sea ice reduce physical habitats for Ringed Seal, but it will also potentially lead to changes in the supply of energy through the system.

Acidification

Warming ocean waters and higher atmospheric CO2 levels will cause increased acidification of the oceans (summarized in Kelly et al. 2010a). The effects of acidification are expected to be most significant in lower trophic levels, where they can affect the ability of some zooplankton to form calcium carbonate shells (Orr et al. 2005). Acidification may also affect the physiology of marine invertebrates and fish (Pörtner et al. 2004; Pörtner 2008). Recent rates of change in acidity have been 100 times faster than in the last 100,000 years (Raven et al. 2005). It is expected that these changes could have indirect effects on Ringed Seal if the ecosystem is restructured due to acidification (Kelly et al. 2010a).

Acidification has secondary impacts because a lowered pH reduces the absorption of low frequency sound (Brewer and Hester 2009). This will make the oceans noisier in the same range of frequencies important for some marine mammals. Although Ringed Seal is not thought to use sound to communicate in the same manner as other seals (e.g., Bearded Seals) and whales, increasing acoustic noise in the marine environment may have other unknown effects such as masking the approach of predators.

Invasive & other problematic species & genes (iucn threats #8.2 [problematic native species/diseases], 8.6 [diseases of unknown cause]) – unknown

Disease

Ringed Seal has co‐evolved with a variety of parasites and diseases. Information on pathologies is limited (Tryland et al. 1999), but some new information has become available in recent years. Antibodies for the morbillivirus phocine distemper virus (PDV) (Cosby et al. 1988), which is antigenically related to canine distemper (Liess et al. 1989), were found in Ringed Seal in eastern Canada in the 1980s and across Arctic Canada in the early 1990s (Osterhaus et al. 1988). The prevalence was highest in areas of the eastern Canadian Arctic, where Ringed Seal was sympatric with Harp Seal (Duignan et al. 1997), which have been implicated in a PDV epizootic in Harbour Seal populations in western Europe in 1998 (Heide-Jørgensen et al. 1992b). Overall, prevalence of PDV has been higher than expected in Ringed Seal considering their solitary and territorial behaviour, although transmission could occur among subadults aggregating in sub-optimal breeding habitat (Duignan et al. 1997).

The number of tumours reported in marine mammals has increased, including the first case of adenocarcinoma of the small intestine in Pinnipedia, which was reported for an 11-year old Ringed Seal in Hudson Bay (Mikaelian et al. 2001). This increase, however, may be more of an indication of the number of animals and pathogens being investigated than of actual prevalence. The same can be said for parasites. However, some potential expansions have been confirmed by Aboriginal Traditional Knowledge, such as the increase in the frequency of liver abnormalities Inuit hunters reported in their Ringed Seal catches in Admiralty Inlet, Nunavut (Furgal et al. 2002). The small white nodules and lesions may have been caused by an infection by a trematode, which had been previously reported in the livers and gall bladders of Ringed Seal (Dawes 1956), but the reason for the increased prevalence is unclear. An Inuit hunter from Clyde River also recently reported that the livers of some seals did not appear healthy (Dowsley 2005, 2007).

Since 2011, a novel ulcerative dermatitis disease has been reported in Ringed Seal from Northern Alaska (Stimmelmayr in Kovacs 2014). The disease is characterized by a variety of lesions on the eyes, snout, hind flippers, tail and trunk of all age classes. Affected individuals are lethargic and unusually approachable and have an increased tendency to haul out on land (Huntington et al. 2016, 2017). Inuvialuit hunters have also found dead seals on beaches, and with similar symptoms, in the Canadian Beaufort Sea (Joint Secretariat 2015). The disease appears to impact the lungs, liver and immune system, and results in some mortality (Kovacs 2014). Hunters in Davis Strait, Baffin Bay and eastern Hudson Bay have also observed hair loss in Ringed Seal (Dowsley 2005, 2007; Kotierk 2010; Government of Nunavut 2011). Nunavik hunters have expressed concern about the health of Ringed Seal in Hudson Bay, Ungava Bay and Hudson Strait, with observations of sick seals and changes in condition (seals sinking instead of floating) (Nunavik Marine Regional Wildlife Board, unpublished data).

Intracellular pathogens from the genus Brucella have also been detected in Ringed Seal. Forbes et al. (2000) were the first to find this organism in an individual from Pangnirtung in 1995, and this was the first confirmed case of brucellosis in marine mammals from Canada. Nielsen et al. (1996) found anti-Brucella antibodies in Ringed Seal through a serological survey of marine mammals from the Canadian Arctic. Although some hosts are asymptomatic, Brucellosis infections have been associated with placentitis/abortions, neonatal mortality, meningoencephalitis, abscesses and other syndromes in marine mammals. The Brucella bacteria is likely transmitted to Ringed Seal from enzootically infected animals such as the Arctic Fox (Nielsen et al. 1996, 2001; Tryland et al. 1999). In one study, the infection in true seals sampled in Alaska seems to be relatively common yet shown to be transient and decreasing with increasing age for Harbour Seal, becoming virtually absent at the age of sexual maturity. Similar patterns were present also for the other true seal species including Ringed Seal; however, firm conclusions could not be made due to sample size (Nymo et al. 2018). Quakenbush tested Ringed Seal sampled in Alaska between 2003 and 2014 and reported that 4 of 93 (4.3%) tested positive (Quakenbush 2015).

Ringed Seal is also an intermediate host of one of the most common parasites in the world (Tenter et al. 2000), the coccidian parasite Toxoplasma gondii, which is a cause of encephalitis in marine mammals (Dubey et al. 2003). In the first large-scale study of T. gondii in the Canadian Arctic, Simon et al. (2011) found that prevalence in Ringed Seal ranged from 2.4% in Chesterfield Inlet, to 5.8–7.9% in Ulukhaktok, Tuktoyaktuk, Sachs Harbour and Sanikiluaq, to 15.6% in Arviat and 23.1% in the Hall Beach area. They also found year-to-year variation in prevalence and reported that seroprevalence did not increase continuously with age (Simon et al. 2011). This latter pattern did not appear to be linked to morbidity or mortality rates of T. gondii infection (Gajadher et al. 2004), transplacental transmission (Miller et al. 2008; Dubey 2010) or spontaneous clearing of infection from adults (Gajadher et al. 2004; Dubey 2010), and the authors concluded that it likely indicates that Ringed Seal becomes infected at a young age (Simon et al. 2011). The behaviour(s) that subject young seals to higher rates of infection remains unclear, but diet likely plays a role (Born et al. 2004; Robertson 2007; Massie et al. 2010; Vincent-Chambellant 2010).

Wild and domestic felids are the only known definitive hosts of T. gondii (Measures et al. 2004; Dubey 2010), which appears to be transferred to marine environments via oocysts in surface run-off (Conrad et al. 2005; Miller et al. 2008). Fecal contamination of marine environments by terrestrial mammals is also a problem for other protozoan parasites such as Giardia and Cryptosporidium (Appelbee et al. 2005; Miller et al. 2010). Cysts from Giardia were found in Ringed Seal in the Ulukhaktok area of the Northwest Territories in 1997 (Olsen et al. 1997), which appears to be the first report of this infection in marine mammals. These seals were also tested for Cryptosporidium but were negative, although infections have been found in other Ringed Seal (Hughes-Hanks et al. 2005). Transmission from terrestrial and marine mammals could also be occurring with Neospora canium, the antibodies for which were first reported in Ringed Seal in Alaska, but the mode of transmission is unclear (Kovacs 2014).

The most abundant parasites hosted by Ringed Seal are helminths of the gut tract (Johansen et al. 2010), including nematodes that create some damage to the tissue of their intermediate and definitive hosts. Ringed Seal is often infected by anisakids, the adult and larval stages of which live in the gastric and intestinal parts of the digestive tract. Common species include Contacaecum osculatum, which is morphologically indistinguishable from another anisakid worm, its sister species Pseudoterranova decipiens (McClelland 1980; Brattey and Stenson 1993). P. bulbosa, a nematode previously only recorded in Bearded Seal, was also recently found, along with C. osculatum, in the stomach of a Ringed Seal in Arviat, Nunavut (Karpiej et al, 2014). Ringed Seal appears to be the definitive host for C. osculatum and P. decipiens, based on evidence of adult specimens in the stomachs of Ringed Seal from Arviat (Soltysiak et al. 2013). Both species have been associated with ulcerous gastric lesions and inflammation in the stomach (McClelland 1980), where the degree of pathological changes appears to be determined by proportion of each species, size of infection and host diet and immunity (Soltysiak et al. 2013).

The nematode Trichinella nativia has been found in Ringed Seal at low prevalences (Forbes 2000). A lower prevalence in Ringed Seal compared to Polar Bear, Walrus, and Arctic Fox could be because cannibalism is a primary means of infection for these hosts and Ringed Seal is only infrequently exposed to infected carcasses (Forbes 2000).

Ringed Seal is also host for three genera of lung nematodes: Otostrongylus sp., Dipetalonema sp. (Delyamure 1955) and Parafilaroides sp. (Delyamure and Alexiev 1966), two of which have been reported in Ringed Seal in the Amundsen Gulf. There, Parafilaroides hispidus caused no significant lesions but O. circumlitus caused extensive mucous production, mucosal hyperplasia, peribronchitis and endarteritis, mainly in young of the year, 28% of which had concurrent infections (Onderka 1989). The prevalence of the nematode is similar in the eastern Arctic (Bergeron et al. 1997), and it could also be impacting diving abilities, and ultimately survival (Bergeron et al. 1997; Gosselin et al. 1998). The heartworm Acanthocheilonema spirocauda (Measures et al. 1997) also infects Ringed Seal, particularly when they are young.

Pollution (IUCN Threats #9.1 [domestic & urban waste water], 9.2 [industrial and military effluents], 9.3 [agricultural and forestry effluents], 9.4 [garbage & solid waste], 9.5 [air-borne pollutants]) – unknown

Much of the work on pollutants and contaminants in Ringed Seal relate to human health concerns for northern people who consume marine mammals; secondarily, some research has also focused on the implications for Polar Bear and possible population effects of contaminants (Zhu et al. 1995; Dietz et al. 1998; Muir et al. 1999; Fisk et al. 2005; Letcher et al. 2010; AMAP 2018). Ringed Seal is one of the top predators in the Arctic food chain and, as such, can bioaccumulate these compounds. Tynan and DeMaster (1997) noted that climate change could increase the transport of pollutants into the Arctic from lower latitudes due to increased precipitation bringing more contaminated water to the Arctic.

Noise

Exploration and drilling activities, and the infrastructure needed to supply and maintain sites, can be a source of disturbance through direct displacement of animals from habitat. Noise has been identified as a potential source of disturbance for Ringed Seal in this context (Southall et al. 2007). Seismic surveys create a sound wave that is used to image the sea floor and subsurface layers. In recent years, for open-water surveys, the sound waves are created using compressed air (Harris et al. 2001). Using a mid-powered airgun array, Harris et al. (2001) noted some avoidance by Ringed Seal of areas within 150 m of operation but little change in behaviour farther from the ship. They did note the most common behaviours were diving and swimming away, but also noted that the observers were primarily tasked with detection of marine mammals within a defined radius and thus could not follow behaviours effectively. They observed seals close to the array when it was firing but overall seals were farther away (median distance 234 m) during operations compared to when the guns were not firing (median distance 144 m). Seismic exploration activities have been approved for the Canadian side of Baffin Bay but court challenges are ongoing (Skura 2016).

Ringed Seal is also susceptible to disturbance by noise during the ice-covered season when they are hauled out in dens or on the ice moulting. Kelly et al. (1986) documented Ringed Seal exiting their dens in response to a variety of anthropogenic activities from approaches by humans and dogs to snowmobiles and helicopters. In general, they found that mechanical noise caused a reaction at farther distances. They also observed that there were fewer active seal structures within 150 m of seismic lines and that Ringed Seal abandoned dens three times more frequently in areas of noise disturbance (Kelly et al. 1986). The energetic cost of abandoning a den is unknown but may be significant (Kelly et al. 2010a). Moulton et al. (2005) surveyed haul-out densities of Ringed Seal before, during, and after the construction of a gravel island and subsequent drilling operations. They concluded that there was no significant change in spring Ringed Seal density over this time period (1997 to 2001; Moulton et al. 2005). Similarly, Harwood et al. (2007) found no detectable effect of one season of drilling on Ringed Seal in the Beaufort Sea using a before – during study design. Using telemetry data, Cott et al. (2003) reported that seismic surveys in the Beaufort Sea did not appear to affect the timing or route of Ringed Seal migration.

Noise also could potentially cause physical damage to seals near the source. This could be in the form of hearing loss or auditory threshold shifts (Clark 1991). Although seals have been observed near sources of intense sound (e.g., seismic activity, blasting, pile driving) it is unknown if they incur hearing damage. Hastie et al. (2015) tracked Harbour Seals and predicted noise levels for each seal due to pile driving activities. They suggest that for half of the seals they tracked the sound exposure exceeded the estimated permanent auditory damage threshold. The noise impacts on Ringed Seal remain largely unknown.

Spills

Risk of harm to marine mammals from an oil spill has long been identified (Engelhardt 1983) and some oiling experiments have been conducted on Ringed Seal (Smith and Geraci 1975; Engelhardt et al. 1977). They may be at higher risk in the event of an oil spill when there is ice cover because the oil will concentrate in cracks and leads that seals are forced to use to breathe (Engelhardt 1983). Contact and ingestion can occur when compounds are inhaled or can occur when the oil adheres to the fur and is either absorbed through the skin or when it is groomed off (Smith and Geraci 1975). Engelhard (1983) noted that oiled seals passively cleaned their pelage within one day of swimming in clean water in contrast to Sea Otter (Enhydra lutris) and Polar Bear, which groomed the oil out of their pelage. However, kidney damage was noted along with potential liver involvement that could progress if the experiment was longer (7 days) (Engelhardt et al. 1977).

Smith and Geraci (1975) conducted field and laboratory oiling experiments and while seals oiled in the field recovered, all three laboratory-oiled seals died within 71 min of oiling. They noted that the laboratory animals likely had much higher levels of stress related to captivity that contributed to the outcome but also noted that oil spills in a year which seals were already stressed could have a magnified impact on the population (Smith and Geraci 1975). Eye damage has also been noted as a risk to Ringed Seal in oiled waters (Engelhardt 1983).

Direct exposure to crude oil damages Ringed Seal eyes and accumulates in some tissues, and prolonged exposure could be fatal, but the potential impacts of oil spills on Ringed Seal populations are unclear in expansive areas where seals can avoid the affected area (McLaren 1990). However, residues from the consumption of oiled fish can accumulate in tissues such as blubber, which compromises liver and kidney function when metabolized (Smith and Geraci 1975; Engelhardt 1983). In addition, the impacts of oil spills on Ringed Seal populations could be severe if they occurred close to breeding habitats (Smith 1987).

Persistent organic pollutants

Persistent organic pollutants (POPs) found in pesticides have been shown to accumulate in the fatty tissues of lower trophic levels and be transferred up the food chain to Ringed Seal (Muir et al. 1988, 1992, 1999; Letcher et al. 2010; AMAP 2017). In particular, organochlorine contaminants (OCs) have been a concern given the impacts on health and reproductive performance of seals (e.g., Helle et al. 1976; Helle 1980). While concentrations of “legacy” OCs in Ringed Seal have declined significantly in the Arctic (Addison and Smith 1974; Muir et al. 1999; Rigét et al. 2004, 2018), those of OCs such as chlorobenzenes and endosulfan have been increasing in the Canadian Arctic (Muir et al. 1999; Rigét et al. 2018), with higher concentrations observed in the west than in the east (e.g., Kucklick et al. 2006).

Several new classes of chemicals have been detected in Ringed Seal such as polybrominated diphenyl ethers (PBDEs), short chain chlorinated paraffins (SCCPs), polychlorinated naphthalenes (PCNs), perfluoro-octane sulfonic acids (PFOS) and perfluorocarboxylic acids (PFCAs) (Martin et al. 2004; Wolkers et al. 2004; Bossi et al. 2005; Braune et al. 2005; Quakenbush 2007; Quakenbush and Citta 2008). PBDEs are widely used as flame retardants and are known to accumulate in lipids (Hites 2004; AMAP 2017). Levels are increasing in humans and marine mammals with a doubling time of about 7 years for Canadian marine mammals (Hites 2004). However, research is only starting to emerge regarding levels, trends and effects for most compounds (Kovacs 2014).

Heavy metals

Important heavy metals studied in Ringed Seal include mercury, lead, cadmium, nickel, arsenic and selenium (see Wagemann and Muir 1984; Wagemann et al. 1996; Rigét and Dietz 2000; Dietz et al. 2013). Mercury and cadmium have been studied across the range of Ringed Seal and are variable among sites, with higher mercury concentrations in the liver in the western Canadian Arctic and higher cadmium levels in the eastern Canadian Arctic (Rigét et al. 2005). They also found that concentrations of both mercury and cadmium were higher in adult seals compared to subadults in all locations.

The long-term pattern in mercury concentration derived from teeth indicates that levels were low and stable in the western Canadian Arctic from pre-industrial times to the 19th century but then increased dramatically in the current era (Outridge et al. 2009). On a short-term scale, a pattern of higher muscle mercury levels in both shorter (heavier ice) and longer (light ice) open-water seasons compared to average years was detected in Ringed Seal from the Amundsen Gulf (Gaden et al. 2012). The authors attributed this to changes in the availability of prey (Arctic Cod) and thus mercury exposure.

Limiting factors

Predation

Ringed Seal is vitally important prey for Polar Bear, which typically consume one seal every few days when hunting on sea ice (Kovacs 2014). Bears hunt seals in moving, offshore ice, as well as along floe edges and on stable shorefast ice (Stirling and Archibald 1977; Stirling and Latour 1978; Smith 1980). In winter, they are most successful in ice-edge and shear-zone areas inhabited by naive subadult seals, and have less success catching breeding adults in the fast ice (Kingsley 1990; Keith et al. 2005; Joint Secretariat 2015).

Hammill and Smith (1991) estimated that 75-100% of Ringed Seal killed by Polar Bear were pups, and that bears removed from 8 to 44% of the annual pup production prior to weaning in Barrow Strait. However, they considered this a potential underestimate given that their study concluded 4-6 weeks prior to break-up, a period during which bears would have continued to feed heavily (Ramsay and Stirling 1988).

Stirling and Øritsland (1995) calculated that a population containing 1,800 Polar Bear would need ca. 77,400-80,293 Ringed Seal per year, and Kingsley (1998) estimated that the Polar Bear in Baffin Bay (N = ca. 4,000) would need to eat 120,000 to 160,000 Ringed Seal per year to sustain themselves. Across the entirety of the Canadian range, Kingsley (1990) estimated that 15,000-20,000 Polar Bear, each needing 40 seals/year, would kill 600,000-800,000 seals annually—an order of magnitude larger than the human harvest.

The global distributions of Arctic Fox and Ringed Seal overlap broadly (Hersteinsson and Macdonald 1992), and foxes spend considerable time on the sea ice (Smith 1976; Kingsley 1990; Roth 2002; Pamperin et al. 2008). In the western Canadian Arctic, Arctic Fox was the most frequent cause of death among young (< 1 year old) Ringed Seal, with 9-40% of the annual pup production killed (Smith 1976, 1987). Significant predation has also been documented in the southeast Baffin Island area (Smith 1976; Smith et al. 1979). In other regions, Arctic Fox entered 21% (Svalbard) and 13% (Alaskan Beaufort Sea) of lairs and killed 38% and 25% of the pups in those lairs, respectively (Lydersen and Gjertz 1986; Kelly and Quakenbush 1990). There are no estimates of the average or typical rates of fox-related mortality across the species’ range (Kingsley 1990). As with Polar Bear, interannual variation in Ringed Seal predation rates have been detected for Arctic Fox, with rates increasing in years when lemming (Lemmus trimucronatus and Dicrostonyx sp.) populations are low (Roth 2003).

There is no information on predation rates from Atlantic Walruses, but Inuit in eastern Canada note that it occurs most often in areas where deep water makes it harder for Walruses to access benthic prey (Gunn et al. 1988; Piugattuk 1990; Kappianaq 1992; Kappianaq 1997). Predation by Greenland Sharks similarly cannot be quantified (Kelly et al. 2010a).

Killer Whale observations are increasing in both the eastern Canadian Arctic and in Alaskan and Russian waters (the Beaufort and Chukchi seas; George and Suydam 1998; Melnikov et al. 2007; Higdon and Ferguson 2009; Higdon et al. 2012, 2014). Killer Whale Predation on Ringed Seal has been recorded in eastern Canada (Higdon 2007; Ferguson et al. 2012a,b). Killer Whale are occasionally seen in the Canadian Beaufort Sea, but predation on Ringed Seal has not been observed there (Higdon et al. 2013). Predation rates are unknown, and may be increasing, but overall are likely minor in relation to losses from Polar Bear and Arctic Fox.

Predation by other species (e.g., gulls, Common Raven, wolves) is negligible over most of the species’ range (Kelly et al. 2010a).

Number of locations

Habitat deterioration from sea-ice decline and lack of adequate snow cover associated with human-induced climate change is the most common plausible threat to the population, but there is considerable variation predicted in the severity and timing of change in ice conditions in the future over a very large area (Habitat trends section). Therefore, the number of locations is unknown, but considered to exceed thresholds.

Protection, status and ranks

Legal protection and status

There are no international agreements or conventions specifically intended to protect Ringed Seal, but the International Agreement on the Conservation of Polar Bears and their Habitat protects Polar Bear feeding areas, which implies a measure of protection for Ringed Seal and their habitat (Kingsley 1990). Ringed Seal is not listed on any appendix of CITES [Convention on International Trade in Endangered Species]. COSEWIC assessed the species as Special Concern in November 2019; it was previously assessed as “Not at Risk” in 1989, and it is currently not listed under the Species at Risk Act.

In December 2012, NOAA Fisheries announced that the Arctic, Baltic (P. h. botnica) and Okhotsk Sea (P. h. ochotensis) subspecies of Ringed Seal would be listed as Threatened under the United States Endangered Species Act (NOAA 2012). This listing was challenged in court and Ringed Seal was delisted (Muto et al. 2017); however, the ruling was reversed and Ringed Seal is currently listed as Threatened under the United States Endangered Species Act. The Arctic Ringed Seal that exist in U.S. waters were already protected under the Marine Mammal Protection Act (MMPA). Ringed Seal is ranked as Least Concern in Greenland (Boertmann 2007), Vulnerable in Norway (Svalbard) (Swenson et al. 2010) and are not listed in Russia (Red Data Book 2001).

In Canada, Ringed Seal, like all marine mammals, fall under the Marine Mammal Regulations (SOR/93-56) of the Fisheries Act (Government of Canada 2015). In 1980, the Seal Protection Regulations (C.R.C., c. 833) were enacted under the Fisheries Act, which permitted any resident to take seals for themselves, their family or dogs, or to sell or trade seal meat to a resident or a traveller for the same purpose (Department of Fisheries and Oceans 1978). These provisions placed no restrictions on the sale or barter of skins produced through the harvest (Kingsley 1990). In 1993, the Seal Protection Regulations were consolidated with those for other marine mammals in the Marine Mammal Regulations of the Fisheries Act. Seal hunting in the marine waters of the Northwest Territories, Nunavut, Nunavik and Labrador are co-managed by various wildlife management boards (Fisheries Joint Management Committee (FJMC) in the Inuvialuit Settlement Region (Northwest Territories), Nunavut Wildlife Management Board (NWMB) in the Nunavut Settlement Area, Nunavik Marine Region Wildlife Board (NMRWB) in the Nunavik Marine Region, and Torngat Joint Fisheries Board (TJFB) in the Labrador Inuit Settlement Area), under the applicable sections of their respective land claims agreements. The co-management process in two of these jurisdictions, Nunavut and Nunavik, is briefly described in COSEWIC (2017). Scientific advice is provided by the Department of Fisheries and Oceans, which manages Ringed Seal in other jurisdictions in cooperation with other agencies.

The Marine Mammal Regulations of the Fisheries Act also include a provision (MMR 4(1)) for a Marine Mammal Fishing Licence (MMFL) for Ringed Seal. Less than 100 of these licences were being sold per year in the 1980s (Kingsley 1990). In the most recent 10-year period, 2007 to 2016 inclusive, an average of 22 (median 21) licences were sold each year from the Iqaluit Fisheries and Oceans Canada office (range 4-51) (Hall pers. comm. 2017), most in relation to Walrus Sport Hunters who also request a seal licence (Young pers. comm. 2017). An MMFL for harvesting seal would only be issued to a non-resident who is visiting Nunavut. A small number of licences would also be issued by other agencies (e.g., Government of Nunavut Department of the Environment) in outlying communities, but annual totals for Nunavut are likely well below 100 (Young pers. comm. 2017; Hall pers. comm. 2017). Small numbers may be sold to visitors to other jurisdictions within the Ringed Seal range, which generally falls within Seal Hunting Areas 1 to 4. As specified in the Marine Mammal Regulations, a resident immediately adjacent to these areas may also hunt for seals without a licence for food purposes. All MMFLs include a condition to “Report harvest to local DFO office”, but it is very rare for DFO to receive a report on a seal harvesting (Young pers. comm. 2017).

Non-legal status and ranks

At the species level, Ringed Seal is “Least Concern” on the IUCN Red List (Lowry 2016), and the Arctic, Baltic, and Okhotsk Sea subspecies are similarly ranked (Boveng 2016a,b; Härkönen 2015). The other two subspecies are at risk; the Ladoga Ringed Seal, P. h. ladogensis being listed as Vulnerable (Sipilä 2016a) and the Saimaa Ringed Seal, P. h. saimensis being listed as Endangered (Sipilä 2016b).

Canadian wildlife species are assessed via the NatureServe ranking process through the Program on the General Status of Species in Canada, through which Ringed Seal is ranked “N5B, N5N, N5M” (Secure) at the national and sub-national (Western Arctic Ocean, Eastern Arctic Ocean, and Atlantic Ocean) scales (CESCC 2016).

Habitat protection and ownership

Existing and proposed protected areas such as national parks, national wildlife areas (NWAs), migratory bird sanctuaries, Oceans Act marine protected areas (MPAs), national marine conservation areas, Indian Reservations, and other lands owned and managed by the Government of Canada afford little protection to Ringed Seal habitat. Some seals use the sea ice adjacent to protected terrestrial areas, but these sites offer no specific protection of Ringed Seal habitat. The Ninginganiq NWA in northeast Baffin Island includes the shoreline and islands of Isabella Bay and adjacent ocean out to 12 nautical miles from shore, and thus directly protects some important fast ice habitat for Ringed Seal. Some habitat is also protected by MPAs in the Inuvialuit Settlement Region (Anguniaqvia Niqiqyuam, Tarium Niryutait) and southern Labrador (Gilbert Bay). The Lancaster Sound NMCA, once finalized, should offer additional protection. Inuit and Inuvialuit have the right to hunt in national parks and other conservation areas within the Inuvialuit Settlement Region, Nunavut, Nunavik, and Nunatsiavut.

Acknowledgements

This work benefited from discussions with numerous experts both within and outside COSEWIC. Within COSEWIC, information and advice were gratefully received from Alain Filion (distribution range mapping), Jenny Wu (GIS-based calculations), Neil Jones (ATK information), Hal Whitehead and David Lee (SSC Co-Chairs), and Karen Timm (assistance with organization and communications). At Fisheries and Oceans Canada, Steve Ferguson and Patt Hall in Winnipeg (Manitoba), Jean-François Gosselin and Mike Hammill in Mont-Joli (Québec), Garry Stenson in St. John’s (Newfoundland and Labrador), and Jeremiah Young in Iqaluit (Nunavut) provided information and assistance. All provided valuable contributions on Ringed Seal ecology, distribution, management, and conservation. Maha Ghazal (Government of Nunavut) provided information on sealing and sealskin sales in Nunavut, Kaitlin Breton-Honeyman (Nunavik Marine Region Wildlife Board) provided information on hunters concerned about Ringed Seal health in Nunavik, Jayko Alooloo (Pond Inlet) and Moshi Kotierk (Government of Nunavut) provided valuable perspective on potential impacts of cruise ship tourism in Nunavut, and Lori Quakenbush (Alaskan Department of Fish and Game) provided information on Alaskan Ringed Seal harvest levels. The draft report was greatly improved by reviews from numerous jurisdictions and boards.

Authorities contacted

Alooloo, J. pers. comm. 2013. Discussion with J.W. Higdon. October 2013. Pond Inlet, Nunavut..

Breton-Honeyman, K. pers. comm. 2018. Email correspondence to J.W. Higdon. March 2018. Director of Wildlife Management, Nunavik Marine Region Wildlife Board, Inukjuak, Quebec.

Ferguson, S.H. pers. comm. 2017. Email correspondence to J.W. Higdon and S.H. Petersen. January-August 2017. Research Scientist, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba.

Ghazal, M. pers. comm. 2017. Email correspondence to S.D. Petersen. April-August 2017. Marine Mammal Advisor, Government of Nunavut, Pangnirtung, Nunavut.

Gosselin, J-F. pers. comm. 2017. Email correspondence to J.W. Higdon. April 2017. Biologist, Maurice Lamontage Institute, Fisheries and Oceans Canada, P.O. Box 1000, 850 route de la Mer, Mont-Joli, Quebec.

Hall, P. 2017. pers. comm. Email correspondence to J.W. Higdon. April 2017. Regional Senior Officer, Fishery Management, Fisheries and Oceans Canada, 501 University Crescent, Winnipeg, Manitoba.

Hammill, M. pers. comm. 2017. Email correspondence to J.W. Higdon. April 2017. Research Scientist, Maurice Lamontage Institute, Fisheries and Oceans Canada, P.O. Box 1000, 850 route de la Mer, Mont-Joli, Quebec.

Kotierk, M. pers. comm. 2013. Discussion with J.W. Higdon. October 2013. Social Scientist Researcher, Department of Environment, Government of Nunavut, Igloolik, Nunavut.

Quakenbush, L. pers. comm. 2018. Review comments on draft report provided to J.W. Higdon, S.D. Petersen and M. Hainstock. February 2018. Arctic Marine Mammal Program, Alaska Department of Fish and Game, Fairbanks, Alaska.

Stenson, G. pers. comm. 2017. Email correspondence to J.W. Higdon. April 2017. Research Scientist and Head, Marine Mammal Section, Science Branch, Fisheries and Oceans, Canada, P.O. Box 5667, St. John’s, Newfoundland.

Young, J. pers. comm. 2017. Email correspondence to J.W. Higdon. April 2017. Fisheries Management Technician, Fisheries and Oceans Canada, P.O. Box 358, Iqaluit, Nunavut.

Information sources

ACIA. 2005. Arctic Climate Impact Assessment. Cambridge University Press, Cambridge, UK. 1042 p. Online: http://www.acia.uaf.edu.

Addison, R. F., and T. G. Smith. 1974. Organochlorine residue levels in Arctic ringed seals: variation with age and sex. Oikos 25:335–337.

Allen, J.A. 1880. History of North American pinnipeds. A monograph of the walruses, sea lions, sea bears, and seals of North America. U.S. Geol. Geogr. Surv. Terr. Misc. Publ. No. 12.

Allen, B. M., and Angliss, R. P. 2010. Alaska marine mammal stock assessments, 2009. U.S. Department of Commerce, NOAA Tech. Memo. NMFS-AFSC-206. 276 pp.

Amano, M., A. Hayano, and N. Miyazaki. 2002. Geographic variation in the skull of the ringed seal, Pusa hispida. J. of Mamm. 83:370–380.

AMAP. 2007. Arctic Oil and Gas 2007. Arctic Monitoring and Assessment Programme (AMAP).

AMAP. 2017. Chemicals of Emerging Arctic Concern. Arctic Monitoring and Assessment Programme (AMAP), Oslo, Norway.

AMAP. 2018. AMAP Assessment 2018: Biological Effects of Contaminants on Arctic Wildlife and Fish. Arctic Monitoring and Assessment Programme (AMAP), Tromso, Norway. xvi+353pp (ISBN – 978-82-7971-106-3).

Anderson, R. M. 1946. Catalogue of Canadian recent mammals. Ottawa, National Museum of Canada.

Andriashek, D., and C. Spencer. 1989. Predation on a ringed seal, Phoca hispida, pup by a red fox, Vulpes vulpes. Can. Field-Nat. 103:600.

Árnason, Ú., A. Gullberg, A. Janke, M. Kullberg, N. Lehman, E. A. Petrov, and R. Väinölä. 2006. Pinniped phylogeny and a new hypothesis for their origin and dispersal. Mol. Phylog. Evol. 41:345–354.

Appelbee, A. J., R. C. Thompson, and M. E. Olson. 2005. Giardia and Cryptosporidium in mammalian wildlife - current status and future needs. Trends Parasitol. 21:370–376.

Beem, H. R., and M. S. Triantafyllou. 2015. Wake-induced ‘slaloming’response explains exquisite sensitivity of seal whisker-like sensors. J. Fluid Mech. 783:306–322.

Belikov, S. E., and A. N. Boltunov. 1998. The ringed seal (Phoca hispida) in the western Russian Arctic. Pages 63–82 in M. P. Heide-Jørgensen and C. Lydersen, editors. Ringed Seals in the North Atlantic. NAMMCO Sci. Publ. Vol. 1. Tromsø, Norway.

Bengtson, J. L., L. M. Hiruki-Raring, M. A. Simpkins, and P. L. Boveng. 2005. Ringed and bearded seal densities in the eastern Chukchi Sea, 1999–2000. Polar Biol. 28:833–845.

Berger, T. 1976. Transcripts of the Proceedings at the Community Hearing of the Mackenzie Valley Pipeline Inquiry before the Honourable Mr. Justice Berger, Commissioner. Sachs Harbour, N.W.T. March 4, 1976. Volume 42. 2003 electronic version. Allwest Reporting Ltd., Vancouver, B.C. 122 pp.

Bergeron, E., L.N. Measures, and J. Huot. 1997. Lungworm (Otostrongylus circumlitus) infections in ringed seals (Phoca hispida) from eastern arctic Canada. Can. J. Fish. Aquat. Sci. 54: 2443–2448.

BIMC (Baffinland Iron Mines Corporation). 2012. Mary River Project Final Environmental Impact Statement, February 14, 2012. NIRB File No.: 08MN053. Nunavut Impact Review Board, Cambridge Bay, NU.

BIMC (Baffinland Iron Mines Corporation). 2013. Mary River Project, Addendum to Final Environmental Impact Statement, June 2013. Nunavut Impact Review Board, Cambridge Bay, NU.

Boertmann, D. 2007. Grønlands Rødliste – 2007 [Greenlands Redlist -2007]. Grønlands Hjemmestyre, Direktoratet for Miljø og Natur, Nuuk. In Danish.

Boertmann, D., A. Mosbech, D. Schiedek, and K. Johansen (eds). 2009. The eastern Baffin Bay. A preliminary strategic environmental impact assessment of hydrocarbon activities in the KANUMAS West area. National Environmental Research Institute, Aarhus University, Denmark. 238 pp. [NERI Technical report no. 720;].

Boertmann, D., A. Mosbech, D. Schiedek, and M. Dünweber (Eds.) 2013. Disko West. A strategic environmental impact assessment of hydrocarbon activities. Aarhus University, DCE – Danish Centre for Environment and Energy, 306 pp. [Scientific Report from DCE – Danish Centre for Environment and Energy No. 71.]

Boily, P. 1995. Theoretical heat flux in water and habitat selection of phocid seals and beluga whales during the annual molt. J. Theoret. Biol. 172:235–244.

Born, E. W., J. Teilmann, M. Acquarone, and F. F. Rigét. 2004. Habitat use of ringed seals (Phoca hispida) in the North Water area (North Baffin Bay). Arctic 57:129–142.

Born, E.W., A. Heilmann, L.K. Holm, and K.L. Laidre. 2011. Polar Bears in Northwest Greenland: An Interview Survey About the Catch and the Climate. Museum Tusculanum Press, Copenhagen, Denmark. Originally published in Danish and Greenlandic in 2008. Medd. om Grønland 351, Man & Society 41. 232 p.

Bossi, R., F. F. Rigét, and R. Dietz. 2005. Temporal and spatial trends of perfluorinated compounds in ringed seal (Phoca hispida) from Greenland. Environmental Science & Technology 39:7416–7422.

Boveng, P. 2016a. Pusa hispida hispida, Pages e.T61382318A61382321, The IUCN Red List of Threatened Species 2016.

Boveng, P. 2016b. Pusa hispida ssp. ochotensis, Pages e.T41677A66991702, The IUCN Red List of Threatened Species 2016.

Bradstreet, M. S. W., and K. J. Finley. 1983. Diet of ringed seals (Phoca hispida) in the Canadian High Arctic. LGL Limited Environmental Research Associates, Prepared for Petro-Canada Exploration Inc. by LGL Limited Environmental Research Associates. 36 p.

Brattey, J., and G. B. Stenson. 1993. Host specificity and abundance of parasitic nematodes (Ascxidoidea) from the stomachs of five phocid species from Newfoundland and Labrador. Can. J. Zool.71: 2156–2166.

Braune, B. M., P. M. Outridge, A. T. Fisk, D. C. G. Muir, P. A. Helm, K. Hobbs, P. F. Hoekstra et al. 2005. Persistent organic pollutants and mercury in marine biota of the Canadian Arctic: an overview of spatial and temporal trends. Sci. Total Environ. 351:4–56.

Breton-Provencher, M. 1979. Étude de la population de phoques annelés (Phoca hispida) et des autres pinnipèdes de la région de Poste-de-la-baleine (Nouveau-Québec), GIROQ, Rapport à l’hydro-Québec, Projet Grande-Baleine, Mandat d’avant-projet préliminaire OGB/76-1. 148 Pp.

Brewer, P. G., and K. Hester. 2009. Ocean acidification and the increasing transparency of the ocean to low-frequency sound. Oceanography 22:86–93.

Brooke, L. F., and W. B. Kemp. 1986. Marine resources harvest study 1985, Prepared for the Department of Fisheries and Oceans. Kuujjuaq, Nunvik, Makivik Corporation.

Brown, J., M. Dowdall, J. P. Gwynn, P. Børretzen, Ø. G. Selnæs, K. M. Kovacs, and C. Lydersen. 2006. Probabilistic biokinetic modelling of radiocaesium uptake in Arctic seal species: verification of modelled data with empirical observations. J. Environ. Radioactivity 88:289–305.

Brown, T.A., M.P. Galicia, G.W. Thiemann, S.T. Belt, D.J. Yurkowski, and M.G. Dyck. 2018. High contributions of sea ice derived carbon in polar bear (Ursus maritimus) tissue. PLoS ONE 13(1): e0191631.

Burns, J. J. 1970. Remarks on the distribution and natural history of pagophilic pinnipeds in the Bering and Chukchi Seas. J. of Mamm. 51:445–454.

Burns, J. J., and S. J. Harbo Jr. 1972. An aerial census of ringed seals, northern coast of Alaska. Arctic 25:279–290.

Calvert, W., and I. Stirling. 1985. Winter distribution of ringed seals (Phoca hispida) in the Barrow Strait area, Northwest Territories, determined by underwater vocalizations. Can. J. Fish. Aquat. Sci. 42:1238–1243.

Cameron, M. F., D. B. Siniff, K. M. Proffitt, and R. A. Garrott. 2007. Site fidelity of Weddell seals: the effects of sex and age. Ant. Sci. 19(2):149–155

CESCC (Canadian Endangered Species Conservation Council). 2016. Wild Species 2016: The General Status of Species in Canada. National General Status Working Group. Available at: https://wildspecies.ca/reports.

Carlens, H., C. Lydersen, B. A. Kraft, and K. M. Kovacs. 2006. Spring haul-out behavior of ringed seals (Pusa hispida) in Kongsfjorden, Svalbard. Mar. Mam. Sci. 22:379–393.

Castro de la Guardia, L., A. E. Derocher, P. G. Myers, A. D. Terwisscha van Scheltinga, and N. J. Lunn. 2013. Future sea ice conditions in Western Hudson Bay and consequences for polar bears in the 21st century. Glob. Change Biol. 19:2675–2687.

Chambellant, M. 2010. Hudson Bay ringed seal: ecology in a warming climate, Pages 137-158 in S. H. Ferguson, L. L. Loseto, and M. L. Mallory, eds. A Little Less Arctic, Springer.

Chambellant, M., N. J. Lunn, and S. H. Ferguson. 2012. Temporal variation in distribution and density of ice-obligated seals in western Hudson Bay, Canada. Polar Biol. 35:1105–1117.

Chambellant, M., I. Stirling, and S. H. Ferguson. 2013. Temporal variation in western Hudson Bay ringed seal Phoca hispida diet in relation to environment. Ma. Ecol. Prog. Ser. 481:269–287.

Chan, F. T., J. E. Bronnenhuber, J. N. Bradie, K. L. Howland, N. Simard, and S. A. Bailey. 2012. Risk assessment for ship-mediated introductions of aquatic nonindigenous species to the Canadian Arctic. Can. Sci. Advis. Sec. Res. Doc. 2011/105. vi + 93 p.

Chapskii, K. K. 1940. The ringed seal of western seas of the Soviet Arctic (The morphological characteristic, biology and hunting production). In N. A. Smirnov, editor. Proceedings of the Arctic Scientific Research Institute, Chief Administration of the Northern Sea Route. Izd. Glavsevmorputi, Leningrad, Moscow. (Translated from Russian by the Fisheries Research Board of Canada, Ottawa, Canada, Translation Series No. 1665, 147 p.).

Clark, W. W. 1991. Recent studies of temporary threshold shift (TTS) and permanent threshold shift (PTS) in animals. J. Acoust. Soc. Am. 90:155.

Cleator, H. 2001. Traditional knowledge study of ringed seals: a transcript of interviews with hunters from Chesterfield Inlet, Nunavut. Fisheries and Oceans Canada, Central and Arctic Region, Winnipeg, Manitoba, Canada. 108 pp.

Committee on Taxonomy. 2014. List of marine mammal species and subspecies. www.marinemammalscience.org, Society for Marine Mammalogy.

Communities of Ivujivik, Puvirnituq and Kangiqsujuaq, Furgal, C., Nickels, S., Kativik Regional Government – Environment Department. 2005. Unikkaaqatigiit: Putting the Human Face on Climate Change: Perspectives from Nunavik. Joint publication of Inuit Tapiriit Kanatimi, Nasivvik Centre for Inuit Health and Changing Environments at Université Laval and the Ajunnginiq Centre at the National Aboriginal Health Organization. Ottawa, ON.

Conrad, P. A., M. A. Miller, C. Kreuder, E. R. James, J. Mazet, H. Dabritz, D. A. Jessup, F. Gulland, and M. E. Grigg. 2005. Transmission of Toxoplasma: clues from the study of sea otters as sentinels of Toxoplasma gondii flow into the marine environment. Int. J. Parasit. 35: 1155–1168.

Conn, P. B., J. M. Ver Hoef, B. T. McClintock, E. E. Moreland, J. M. London, M. F. Cameron, S. P. Dahle, and P. L. Boveng. 2014. Estimating multispecies abundance using automated detection systems: ice-associated seals in the Bering Sea. Meth. Ecol. Evol. 5:1280–1293.

Cosby, S. L., S. McQuaid, N. Duffy, C. Lyons, B. K. Rima, G. M. Allan, S. J. McCullough, S. Kennedy, J. A. Smyth, F. McNeilly, and C. Craig. 1988. Characterization of a seal morbillivirus. Nature 336: 115–116.

COSEWIC (Committee on the Status of Endangered Species in Canada). 2014. Guidelines for Recognizing Designatable units. Committee on the Status of Endangered Wildlife in Canada. Ottawa.

COSEWIC (Committee on the Status of Endangered Species in Canada). 2017. COSEWIC assessment and status report on the Atlantic Walrus Odobenus rosmarus rosmarus, High Arctic population, Central-Low Arctic population and Nova Scotia-Newfoundland-Gulf of St. Lawrence population in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. xxi + 89 pp.

Cott, P. A., B. W. Hanna, and J. A. Dahl. 2003. Discussion on seismic exploration in the Northwest Territories, 2000–2003. Can. Man. Rep. Fish. Aquat. Sci. 2648: 42 pp.

Crawford, J. A., K. J. Frost, L. T. Quakenbush, and A. Whiting. 2012. Different habitat use strategies by subadult and adult ringed seals (Phoca hispida) in the Bering and Chukchi seas. Polar Biol. 35:241–255.

Crawford, J.A., Quakenbush, L.T., and J. Citta. 2015. A comparison of ringed and bearded seal diet, condition and productivity between historical (1975–1984) and recent (2003–2012) periods in the Alaskan Bering and Chukchi seas. Prog. Oceanogr. 136:133–150.

Crawford, J.A., K.J. Frost, L.T. Quakenbush, and A. Whiting. 2019. Seasonal and diel differences in dive and haul-out behavior of adult and subadult ringed seals (Pusa hispida) in the Bering and Chukchi seas. Polar Biology 42:65–80.

Davis, C. S., I. Stirling, C. Strobeck, and D. W. Coltman. 2008. Population structure of ice-breeding seals. Mol. Ecol. 17:3078–3094.

Dawes, B. 1956: The Trematoda, with special reference to British and other European forms. Cambridge University Press, London, UK.

Degerbøl, M., and P. Freuchen. 1935. Report of the mammals collected by the Fifth Thule Expedition to Arctic North America. Part I. Systematic notes, Pages 1–67, Report of the Fifth Thule Expedition.

Delyamure, S. L. 1955. Helminthofauna of marine mammals (Ecology and Phylogeny) [In Russian]. Ed. K. I. Skrjabin. Moscow: Izdatel’stvo Akademii Nauk SSR. [1968. Translated by Israel Program for Scientific Translations, Jerusalem, 522 pp.

Delyamure, S. L., and E. V. Alekseev. 1966. Parafilaroides arcticus n. sp. as parasites of the Chukotsk Sea ringed seal [In Russian]. Problemy Parazitologii 6: 11–15. [1992. Can. Trans. Fish. Aquat. Sci. 5564]

DFO (Department of Fisheries and Oceans). 1978. C.R.C. 1978: Seal Protection Regulations made under the Fisheries Act. Published by authority of the Minister, Department of Fisheries and Oceans, Ottawa, ON.

DFO (Department of Fisheries and Oceans). 2011. 2011–2015 Integrated Fisheries Management Plan for Atlantic Seals. Fisheries and Oceans Canada, ON. Website: http://www.dfo-mpo.gc.ca/fm-gp/seal-phoque/reports-rapports/mgtplan-planges20112015/mgtplan-planges20112015-eng.htm.

Derocher, A. E., N. J. Lunn, and I. Stirling. 2004. Polar bears in a warming climate. Int. Comp. Biol. 44:163-176.

Derocher, A. E., Ø. Wiig, and M. Andersen. 2002. Diet composition of polar bears in Svalbard and the western Barents Sea. Polar Biol. 25:448–452.

Diemer, K. M., M. J. Conroy, S. H. Ferguson, D. D. W. Hauser, A. Grgicak-Mannion, and A. T. Fisk. 2011. Marine mammal and seabird summer distribution and abundance in the fjords of northeast Cumberland Sound of Baffin Island, Nunavut, Canada. Polar Biol. 34:41–48.

Dietz, R., P. Paludan-Müller, C. T. Agger, and C. O. Nielsen. 1998. Cadmium, mercury, zinc and selenium in ringed seals (Phoca hispida) from Greenland and Svalbard, Pages 242–272 in M. P. Heide-Jørgensen, and C. Lydersen, eds. Ringed seals in the North Atlantic. Tromsø, Norway, NAMMCO Sci. Publ. Vol. 1.

Dietz, R., C. Sonne, N. Basu, B. Braune, T. O’Hara, R.J. Letcher, T. Scheuhammer, M. Andersen, C. Andreasen, D. Andriashek, G. Asmund, A. Aubail, H. Baagee, E.W. Born, H.M. Chan, A.E. Derocher, P. Grandjean, K. Knott, M. Kirkegaard, A. Krey, N. Lunn, F. Messier, M. Obbard, M.T. Olsen, S. Ostertag, E. Peacock, A. Renzoni, F.F. Riget and J.U. Skaare, 2013. What are the toxicological effects of mercury in Arctic biota? Science of the Total Environment, 443:775–790.

Dowsley, M. 2005. Inuit knowledge regarding climate change and the Baffin Bay polar bear population. Government of Nunavut, Department of Environment, Final Wildlife Report: 1. 43 pp.

Dowsley, M. 2007. Inuit perspectives on polar bears (Ursus maritimus) and climate change in Baffin Bay, Nunavut, Canada. Res. Prac. Social Sci. 2(2): 53–74.

Dubey, J. P. 2010. Toxoplasma gondii infections in chickens (Gallus domesticus): prevalence, clinical disease, diagnosis and public health significance. Zoon. Publ. Health 57(1): 60-73.

Dubey, J. P., R. Zarnke, N. J. Thomas, S. K. Wong, W. Van Bonn, M. Briggs, J. W. Davis, R. Ewing, M. Mense, O. C. H. Kwok, S. Romand, and P. Thulliez. 2003. Toxoplasma gondii, Neospora caninum, Sarcocystis neurona, and Sarcocystis canis-like infections in marine mammals. Vet. Parasit. 116: 275–296.

Duignan, P. J., O. Nielsen, C. House, K. M. Kovacs, N. Duffy, G. Early, S. Sadove, D. J. St. Aubin, B. K. Rima, and J. R. Geraci. 1997. Epizootiology of Morbillivirus infection in harp, hooded and ringed seals from the Canadian Arctic and western Atlantic. J. Wildl. Dis. 33(1): 7–19.

Elsner R., D. Wartzok, N. B. Sonofrank, and B. P. Kelly. 1989. Behavioral and physiological reaction of arctic seals during under-ice pilotage. Can. J. Zool. 67:2506-2513.

Engelhardt, F. R. 1983. Petroleum effects on marine mammals. Aquat. Toxicol. 4:199–217.

Engelhardt, F. R., J. R. Geraci, and T. G. Smith. 1977. Uptake and clearance of petroleum hydrocarbons in the ringed seal, Phoca hispida. J. Fish. Res. Board Can. 34:1143–1147.

Fay, F. H. 1960. Carnivorous walrus and some arctic zoonoses. Arctic 13:111–122.

Fedoseev, G. A. 1975. Ecotypes of the ringed seal (Pusa hispida Schreber, 1777) and their reproductive capabilities, Pages 156-160, Proceedings of a Symposium held in Guelph 14-17 August 1972. Guelph, Ontario, Rapports et Proces-verbaux des Reunions. Conseil International pour l’Exploration de la Mer.

Fedoseev, G. A. 1984. Population structure, current status, and perspective for utilization of the ice inhabiting forms of pinnipeds in the northern part of the Pacific Ocean. Pages 130–146 in A. V. Yablokov, editor. Marine Mammals. Nauka, Moscow, Russia. (Translated from Russian by F. H. Fay and B. A. Fay, 17 p.)

Fedoseev, G. A. 2000. Population biology of ice-associated forms of seals and their role in the northern Pacific ecosystems. Center for Russian Environmental Policy, Russian Marine Mammal Council, Moscow, Russia. 271 p. (Translated from Russian by I. E. Sidorova, 271 p.).

Feltz, E. T., and F. H. Fay. 1966. Thermal requirements in vitro of epidermal cells from seals. Cryobiol. 3:261–264.

Ferguson, S. H., J. W. Higdon, and K. H. Westdal. 2012a. Prey items and predation behavior of killer whales (Orcinus orca) in Nunavut, Canada based on Inuit hunter interviews. Aquat. Biosys. 8:3.

Ferguson, S.H., M.C.S. Kingsley, and J.W. Higdon. 2012b. Killer whale predation in a multi-prey system. Pop. Ecol. 54: 31–41.

Ferguson, S. H., I. Stirling, and P. D. McLoughlin. 2005. Climate change and ringed seal (Phoca hispida) recruitment in western Hudson Bay. Mar. Mam. Sci. 21:121–135.

Ferguson, S. H., B. G. Young, D. J. Yurkowski, R. Anderson, C. Willing, and O. Nielsen. 2017. Demographic, ecological, and physiological responses of ringed seals to an abrupt decline in sea ice availability. PeerJ 5:e2957.

Finley, K. J., G. W. Miller, R. A. Davis, and W. R. Koski. 1983. A distinctive large breeding population of ringed seals (Phoca hispida) inhabiting the Baffin Bay pack ice. Arctic 36:162–173.

Fisk, A. T., C. A. De Wit, M. Wayland, Z. Z. Kuzyk, N. Burgess, R. Letcher, B. Braune et al. 2005. An assessment of the toxicological significance of anthropogenic contaminants in Canadian arctic wildlife. Sci. Tot. Environ. 351:57–93.

Fisk, A. T., S. A. Tittlemier, J. L. Pranschke, and R. J. Norstrom. 2002. Using anthropogenic contaminants and stable isotopes to assess the feeding ecology of Greenland sharks. Ecology 83:2162–2172.

Florko, K. R. N., W. Bernhardt, C. C. Breiter, S. H. Ferguson, M. Hainstock, B. G. Young, and S. D. Petersen. 2018. Decreasing sea ice conditions in western Hudson Bay and an increase in abundance of harbour seals (Phoca vitulina) in the Churchill River. Polar Biol. (https://doi.org/10.1007/s00300-018-2277-6)

Forbes, L. B. 2000, The occurrence and ecology of Trichinella in marine mammals: Vet. Parasit. 93: 321–334.

Forbes, L. B., O. Nielsen, L. Measures, and D. R. Ewalt. 2000. Brucellosis in ringed seals and harp seals from Canada. J. Wildl. Dis. 36: 595–598.

Ford, J. D., W. A. Gough, G. J. Laidler, J. Macdonald, C. Irngaut, and K. Qrunnut. 2009. Sea ice, climate change, and community vulnerability in northern Foxe Basin, Canada. Climate Res. 38:137–154.

Frederiksen, M., D. Boertmann, F. Ugarte, and A. Mosbech (eds). 2012. South Greenland. A Strategic Environmental Impact Assessment of hydrocarbon activities in the Greenland sector of the Labrador Sea and the southeast Davis Strait. Aarhus University, DCE – Danish Centre for Environment and Energy, 220 pp. [Scientific Report from DCE – Danish Centre for Environment and Energy No. 23].

Freeland, J. R., S. D. Petersen, and H. Kirk. 2011. Molecular ecology. Wiley & Sons, Chichester, UK.

Freitas, C., K. M. Kovacs, R. A. Ims, M. A. Fedak, and C. Lydersen. 2008a. Ringed seal post-moulting movement tactics and habitat selection. Oecologia 155:193–204.

Freitas, C., K. M. Kovacs, R. A. Ims, and C. Lydersen. 2008b. Predicting habitat use by ringed seals (Phoca hispida) in a warming Arctic. Ecol. Model. 217:19–32.

Freuchen, P. 1935. Mammals. Part II. Field notes and biological observations, Pages 66-218 in M. Degerbol, and P. Freuchen, eds. Mammals. Copenhagen, Denmark, Gyldendalske Boghandel, Nordisk Forlag.

Frost, K. J. 1985. The ringed seal (Phoca hispida), Pages 79–87 in J. J. Burns, K. J. Frost, and L. F. Lowry, eds., Marine Mammals Species Accounts. Juneau, AK, Alaska Department Fish and Game.

Frost, K. J., and L. F. Lowry. 1981. Ringed, Baikal and Caspian seals, Pages 29–53 in S. H. Ridgway, and R. J. Harrison, eds. Handbook of Marine Mammals. Toronto, Academic Press.

Frost, K. J., L. F. Lowry, G. Pendleton, and H. R. Nute. 2004. Factors affecting the observed densities of ringed seals, Phoca hispida, in the Alaskan Beaufort Sea, 1996–99. Arctic 57:115–128.

Fulton, T. L., and C. Strobeck. 2010. Multiple fossil calibrations, nuclear loci and mitochondrial genomes provide new insight into biogeography and divergence timing for true seals (Phocidae, Pinnipedia). J. Biogeog. 37:814–829.

Furgal, C. M., S. Innes, and K. M. Kovacs. 1996. Characteristics of ringed seal, Phoca hispida, subnivean structures and breeding habitat and their effects on predation. Can. J. Zool. 74:858–874.

Furgal, C. M., S. Innes, and K. M. Kovacs. 2002. Inuit spring hunting techniques and local knowledge of the ringed seal in Arctic Bay (Ikpiarjuk), Nunavut. Polar Res. 21:1–16.

Furnell, D. J., and D. Oolooyuk. 1980. Polar bear predation on ringed seals in ice-free water. Can. Field-Nat. 94:88–89.

Gaden, A., S. H. Ferguson, L. A. Harwood, H. Melling, J. Alikamik, and G. A. Stern. 2012. Western Canadian Arctic ringed seal organic contaminant trends in relation to sea ice break-up. Environ. Sci. Tech. 46:4427–4433.

Gagnon, A. S., and W. A. Gough. 2005. Trends in the dates of freeze-up and breakup over Hudson Bay, Canada. Arctic 58:370–382.

Gajadhar, A. A., L. Measures, L. B. Forbes, C. Kapel, and J. P. Dubey. 2004. Experimental Toxoplasma gondii infection in grey seals (Halichoerus grypus). J. Parasit. 90: 255–259.

Galicia, M. P., G. W. Thiemann, M. G. Dyck, S. H. Ferguson, and J. W. Higdon. 2016. Dietary habits of polar bears in Foxe Basin, Canada: possible evidence of a trophic regime shift mediated by a new top predator. Ecol. Evol. 6:6005–6018.

Galley, R. J., B. G. T. Else, S. E. L. Howell, J. V. Lukovich, and D. G. Barber. 2012. Landfast sea ice conditions in the Canadian Arctic: 1983-2009. Arctic 65(2): 133–144.

Gaston, A. J., H. G. Gilchrist, and J. Hipfner. 2005. Climate change, ice conditions and reproduction in an Arctic nesting marine bird: Brunnich's guillemot (Uria lomvia L.). J. Anim. Ecol. 74:832-841.

Gavrilchuk, K. and V. Lesage. 2014. Large-scale marine development projects (mineral, oil and gas, infrastructure) proposed for Canada’s North. Can. Tech. Rep. Fish. Aquat. Sci. 3069: viii + 84 pp.

George, J. C., and R. Suydam. 1998. Observations of killer whale (Orcinus orca) predation in the northeastern Chukchi and western Beaufort Seas. Mar. Mam. Sci. 14:330–332.

Gjertz, I., K. M. Kovacs, C. Lydersen, and Ø. Wiig. 2000. Movements and diving of adult ringed seals (Phoca hispida) in Svalbard. Polar Biol. 23:651–656.

Gosselin, J.-F., L. N. Measures, and J. Huot. 1998. Lungworm (Nematoda: Metastrongyloidea) infections in Canadian phocids. Can. J. Fish. Aquat. Sci. 55: 825–834.

Government of Nunavut. 2010. Chesterfield Inlet Coastal Resource Inventory Report. Fisheries and Sealing Division, Department of Environment, Iqaluit, NU.

Government of Nunavut. 2011. Sanikiluaq Inlet Coastal Resource Inventory Report. Fisheries and Sealing Division, Department of Environment, Iqaluit, NU.

Government of Nunavut. 2012. Gjoa Haven Coastal Resource Inventory Report. Fisheries and Sealing Division, Department of Environment, Iqaluit, NU.

Government of Nunavut. 2013. Grise Fiord Coastal Resource Inventory Report. Fisheries and Sealing Division, Department of Environment, Iqaluit, NU.

Government of Nunavut. 2014. Pangnirtung Coastal Resource Inventory Report. Fisheries and Sealing Division, Department of Environment, Iqaluit, NU.

Government of Nunavut. 2015. Taloyoak Coastal Resource Inventory Report. Fisheries and Sealing Division, Department of Environment, Iqaluit, NU.

Grebmeier, J. M., J. E. Overland, S. E. Moore, E. V. Farley, E. C. Carmack, L. W. Cooper, K. E. Frey et al. 2006. A major ecosystem shift in the northern Bering Sea. Science 311:1461–1464.

Greenland Home Rule. 2009. Management and utilization of seals in Greenland. Department of Fisheries, Hunting and Agriculture. 24 p.

Government of Canada. 2015. Fisheries Act (R.S.C., 1985, c. F-14).

Gunn, A., G. Arlooktoo, and D. Kaomayok. 1988. The contribution of the ecological knowledge of Inuit to wildlife management in the Northwest Territories, Pages 22–30, Traditional knowledge and renewable resource management in northern regions. IUCN Commission on Ecology and the Boreal Institute for Northern Studies, Occasional Publication.

Hall, E. R., and K. R. Kelson. 1959. The Mammals of North America. Ronald Press, New York, NY.

Hamilton, S. G., L. C. de la Guardia, A. E. Derocher, V. Sahanatien, B. Tremblay, and D. Huard. 2014. Projected polar bear sea ice habitat in the Canadian Arctic Archipelago. PLoS ONE 9:e113746.

Hamilton, C. D., C. Lydersen, R. A. Ims, and K. M. Kovacs KM. 2015. Predictions replaced by facts: a keystone species’ behavioural responses to declining arctic sea-ice. Biology Letters 11: 20150803.

Hammill, M. O. 1987. Ecology of the ringed seal (Phoca hispida Schreber) in the fast-ice of Barrow Strait, Northwest Territories, McGill University, Montreal, Québec, Canada.

Hammill, M. O. 2009. Ringed Seal, Pusa hispida. Pages 972–974 in Encyclopedia of Marine Mammals, 2nd edition. Academic Press. 1352 pp., Pages 972–974 in W. F. Perrin, B. Würsig, and J. G. M. Thewissen, eds. Encyclopedia of Marine Mammals, Academic Press.

Hammill, M. O., C. Lydersen, M. S. Ryg, and T. G. Smith. 1991. Lactation in the ringed seal (Phoca hispida). Can. J. Fish. Aquat. Sci. 48:2471–2476.

Hammill, M. O., and T. G. Smith. 1989. Factors affecting the distribution and abundance of ringed seal structures in Barrow Strait, Northwest Territories. C. J. Zool. 67:2212–2219.

Hammill, M. O., and T. G. Smith. 1990. Application of removal sampling to estimate the density of ringed seals (Phoca hispida) in Barrow Strait, Northwest Territories. Can. J. Fish. Aquat. Sci. 47:244–250.

Hammill, M. O., and T. G. Smith. 1991. The role of predation in the ecology of the ringed seal in Barrow Strait, Northwest Territories, Canada. Mar. Mam. Sci. 7:123–135.

Harcourt, R. G., Hindell M. A., Bell D. G., Waas J. R. (2000) Three dimensional dive profiles of free-ranging Weddell seals. Polar Biol. 23:479–487

Hardy, M. H., E. Roff, T. G. Smith, and M. Ryg. 1991. Facial skin glands of ringed and grey seals, and their possible function as odoriferous organs. Can. J. Zool. 69:189–200.

Harington, C. R. 2008. The evolution of Arctic marine mammals. Ecol. Appl. 18:S23-S40.

Härkönen, T. 2015. Pusa hispida ssp. botnica, Pages e.T41673A66991604, The IUCN Red List of Threatened Species 2016.

Harris, R. E., G. W. Miller, and W. J. Richardson. 2001. Seal responses to airgun sounds during summer seismic surveys in the Alaskan Beaufort Sea. Mar. Mam. Sci. 17:795–812.

Harwood, L. A., T. G. Smith, and J. C. Auld. 2012a. Fall migration of ringed seals (Phoca hispida) through the Beaufort and Chukchi Seas, 2001–02. Arctic 65:35–44.

Harwood, L. A., T. G. Smith, J. C. George, S. J. Sandstrom, W. Walkusz, and G. J. Divoky. 2015. Change in the Beaufort Sea ecosystem: diverging trends in body condition and/or production in five marine vertebrate species. Prog. Oceanog. 136:263–273.

Harwood, L. A., T. G. Smith, and H. Melling. 2000. Variation in reproduction and body condition of the ringed seal (Phoca hispida) in western Prince Albert Sound, NT, Canada, as assessed through a harvest-based program. Arctic 53:422–431.

Harwood, L. A., T. G. Smith, and H. Melling. 2007. Assessing the potential effects of near shore hydrocarbon exploration on ringed seals in the Beaufort Sea region, 2003–2006, Pages 103, Environmental Research Studies Funds, Environmental Studies Research Funds.

Harwood, L. A., T. G. Smith, H. Melling, J. Alikamik, and M. C. Kingsley. 2012b. Ringed seals and sea ice in Canada's Western Arctic: Harvest-based monitoring 1992–2011. Arctic 65:377–390.

Harwood, L. A., and I. Stirling. 1992. Distribution of ringed seals in the southeastern Beaufort Sea during late summer. Can. J. Zool. 70:891–900.

Harwood, J., S. D. Carter, D. E. Hughes, S. C. Bell, J. R. Baker, and H. J. Cornwell. 1989. Seal disease predictions. Nature 339(6227): 670.

Hastie, G. D., D. J. F. Russell, B. McConnell, S. Moss, D. Thompson and V. M. Janik. 2015. Sound exposure in harbour seals during the installation of an offshore wind farm: predictions of auditory damage. J. Appl. Ecol. 52:631–640.

Heide-Jørgensen, M. P., B. S. Stewart, and S. Leatherwood. 1992a. Satellite tracking of ringed seals Phoca hispida off northwest Greenland. Ecography 15:56–61.

Heide-Jørgensen, M. P., T. Harkonen, T., R. Dietz, and P. M. Thompson. 1992b. Retrospective of the 1988 European seal epizootic. Dis. Aquat. Organisms 13(1): 37–62.

Helle, E. 1980. Lowered reproductive capacity in female ringed seals (Pusa hispida) in the Bothnian Bay, northern Baltic Sea, with special reference to uterine occlusions. Annals Zoologici Fennici 17:147–158.

Helle, E., M. Olsson, and S. Jensen. 1976. PCB levels correlated with pathological changes in seal uteri. Ambio 5:261–262.

Heptner, L. V. G., K. K. Chapskii, V. A. Arsen'ev, and V. T. Sokolov. 1976. Ringed seal. Phoca (Pusa) hispida Schreber, 1775. Pages 218-260 in L. V. G. Heptner, N. P. Naumov, and J. Mead, editors. Mammals of the Soviet Union. Volume II, Part 3‐‐Pinnipeds and Toothed Whales, Pinnipedia and Odontoceti. Vysshaya Shkola Publishers, Moscow, Russia. (Translated from Russian by P. M. Rao, 1996, Science Publishers, Inc., Lebanon, NH).

Hersteinsson, P., and D. W. Macdonald. 1992. Interspecific competition and the geographical distribution of red and Arctic Foxes Vulpes vulpes and Alopex lagopus. Oikos 64:505–515.

Hertz, O., and Kapel, F.O. 1986. Commercial and subsistence hunting of marine mammals. Ambio 15(3): 144–151.

Hezel, P. J., X. Zhang, C. M. Bitz, B. P. Kelly, and F. Massonnet. 2012. Projected decline in spring snow depth on Arctic sea ice caused by progressively later autumn open ocean freeze-up this century. Geophys. Res. Let. 39:L17505.

Higdon, J. W. 2007. Status of knowledge on killer whales (Orcinus orca) in the Canadian Arctic. DFO Can. Sci. Advis. Sec. Sci. Advis. Res. Doc. 2007/48: 41 pp.

Higdon, J. W., O. R. P. Bininda-Emonds, R. M. D. Beck, and S. H. Ferguson. 2007. Phylogeny and divergence of the pinnipeds (Carnivora: Mammalia) assessed using a multigene dataset. BMC Evol. Biol. 7:216.

Higdon, J.W., T. Byers, L. Brown, and S.H. Ferguson. 2013. Observations of killer whales (Orcinus orca) in the Canadian Beaufort Sea. Polar Rec. 49: 307–314.

Higdon, J. W., and S. H. Ferguson. 2009. Loss of Arctic sea ice causing punctuated change in sightings of killer whales (Orcinus orca) over the past century. Ecol. Appl. 19:1365–1375.

Higdon, J. W., D. D. W. Hauser, and S. H. Ferguson. 2012. Killer whales (Orcinus orca) in the Canadian Arctic: Distribution, prey items, group sizes, and seasonality. Mar. Mam. Sci. 28:E93-E109.

Higdon, J. W., K. H. Westdal, and S. H. Ferguson. 2014. Distribution and abundance of killer whales (Orcinus orca) in Nunavut, Canada—an Inuit knowledge survey. J. Mar. Biol. Assoc. UK 94:1293–1304.

Hites, R. A. 2004. Polybrominated diphenyl ethers in the environment and in people: a meta-analysis of concentrations. Environ. Sci. Tech. 38:945–956.

Holst, M., and I. Stirling. 2002. A comparison of ringed seal (Phoca hispida) biology on the east and west sides of the North Water Polynya, Baffin Bay. Aquat. Mamm. 28:221–230.

Holst, M., I. Stirling, and W. Calvert. 1999. Age structure and reproductive rates of ringed seals (Phoca hispida) on the northwestern coast of Hudson Bay in 1991 and 1992. Mar. Mam. Sci. 15:1357–1364.

Holst, M., I. Stirling, and K. A. Hobson. 2001. Diet of ringed seals (Phoca hispida) on the east and west sides of the North Water Polynya, northern Baffin Bay. Mar. Mam. Sci. 17:888–908.

Hovelsrud, G. K., M. McKenna, and H. P. Huntington. 2008. Marine mammal harvests and other interactions with humans. Ecol. Appl. 18: S135-S147.

Howell, S. E., C. R. Duguay, and T. Markus. 2009. Sea ice conditions and melt season duration variability within the Canadian Arctic Archipelago: 1979–2008. Geophys. Res. Let. 36:L10502.

Hudson, J. 2016. Landscape genetics of ringed seals (Pusa hispida) in the Canadian Arctic. BSc thesis, University of Winnipeg, Winnipeg, MB.

Hughes-Hanks, J. M., L. G. Rickard, C. Panuska, J. R. Sauciert, T. M. O'Harat, and L. Dehn. 2005. Prevalence of Cryptosporidium spp. and Giardia spp. in five marine mammal species. J. Parasit. 91: 1225–1228.

Huntington, H. P., Quakenbush, L. T., and Nelson, M. 2016. Effects of changing sea ice on marine mammals and subsistence hunters in northern Alaska from traditional knowledge interviews. Biol. Let. 12:20160198.

Huntington, H.P., Quakenbush, L.T., and Nelson, M. 2017. Evaluating the effects of climate change on Indigenous marine mammal hunting in northern and western Alaska using traditional knowledge. Front. Mar. Sci. 4: 319.

Hyvärinen, H. 1989. Diving in darkness: whiskers as sense organs of the ringed seal (Phoca hispida saimensis). J. Zool. 218:663–678.

Hyvärinen, H., and H. Katajisto. 1984. Functional structure of the vibrissae of the ringed seal (Phoca hispida Schr.). Acta Zool. Fenn. 171:27–30.

Iacozza, J., and S. H. Ferguson. 2014. Spatio-temporal variability of snow over sea ice in western Hudson Bay, with reference to ringed seal pup survival. Polar Biol. 37:817–832.

Ice Seal Committee. 2017. The subsistence harvest of ice seals in Alaska - A compilation of existing information, 19602015. In: Report to the Ice Seal Committee. Ice Seal Committee.

IPCC (Intergovernmental Panel on Climate Change). 2013. The Physical Basis. Contributions of Working Group 1 to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change, Pages 1535 pp. in T. F. Stocker, D. Qin, G.-K. Plattner, M. Tignor, S. K. Allen, J. Boschung, A. Nauels et al., eds. Cambridge, United Kingdom and New York, NY, USA, Cambridge University Press.

IUCN (International Union for the Conservation of Nature). 2013. Guidelines for Using the IUCN Red List Categories and Criteria. Version 10, Prepared by the Standards and Petitions Subcommittee.

Jefferson, T. A., S. Leatherwood, and M. A. Webber. 1993. FAO Species Identification Guide: Marine Mammals of the World. Food and Agriculture Organization of the United Nations, Rome.

Johansen, C. E., C. Lydersen, P. E. Aspholm, T. Haug, and K. M. Kovacs. 2010. Helminth parasites in ringed seals (Pusa hispida) from Svalbard, Norway with special emphasis on Nematodes: Variation with age, sex, diet, and location of host. J. Parasit. 96(5): 946–953.

Johnson, M.L., Fiscus, C.H., Ostenson, B.T. and Barbour, M.L. 1966. Marine mammals. Pp. 877–924 in: Environment of the Cape Thompson Region, Alaska / N.J. Wilimowsky and J.N. Wolfe (eds). Oak Ridge, TN: U.S. Atomic Energy Commission.

Joint Secretariat. 2003. Inuvialuit Harvest Study Data and Methods Report 1988–1997. Inuvik, NT. v + 202 p.

Joint Secretariat. 2015. Inuvialuit and Nanuq: A Polar Bear Traditional Knowledge Study. Joint Secretariat, Inuvialuit Settlement Region. Inuvik, NWT.

Jones, J. M., B. J. Thayre, E. H. Roth, M. Mahoney, I. Sia, K. Merculief, C. Jackson et al. 2014. Ringed, bearded, and ribbon seal vocalizations north of Barrow, Alaska: seasonal presence and relationship with sea ice. Arctic 67:203–222.

Kapel, F. O., J. Christiansen, M. P. Heide-Jørgensen, T. Härkönen, E. W. Born, L. Ø. Knutsen, F. Rigét et al. 1998. Netting and conventional tagging used for studying movements of ringed seals (Phoca hispida) in Greenland, Pages 211–228 in M. P. Heide-Jørgensen, and C. Lydersen, eds. Ringed seals (Phoca hispida) in the North Atlantic, North Atlantic Marine Mammal Commission (NAMMCO)

Kapel, F. O., and A. Rosing-Asvid. 1996. Seal hunting statistics for Greenland 1993 and 1994, according to a new system of collecting information, compared to the previous Lists-of-Game. NAFO Sci. Coun. Stud. 26: 71–86.

Kappianaq, G. 1992. Interview IE-234. Igloolik, Nunavut, Archives of the Inullariit Society, Igloolik Research Centre.

Kappianaq, G. 1997. Interview IE-409. Igloolik, Nunavut, Archives of the Inullariit Society, Igloolik Research Centre.

Karpiej, K., M. Simard, E. Pufall, and J. Rokicki. 2014. Anisakids (Nematoda: Anisakidae) from ringed seal, Pusa hispida, and bearded seal, Erignathus barbatus (Mammalia: Pinnipedia) from Nunavut region. J. Mar. Biol. Assoc. UK 94(6): 1237–1241.

Keith, D., J. Arqviq, L. Kamookak, J.Ameralik and the Gjoa Haven Hunters and Trappers Organization. 2005. Inuit Qaujimaningit Nanurnut: Inuit Knowledge of Polar Bears. Gjoa Haven Hunters and Trappers Organization and CCI Press. viii + 252 pp.

Keith, D. 2009. Inuit Observations of Changing Sea Ice and Snow Conditions in Polar Bear Habitat in the East Kitikmeot, Nunavut. In Freeman, Milton M.R. and Lee Foote (eds.). Inuit, Polar Bears and Sustainable Use: Local, National and International Perspectives. Edmonton: CCI Press, pp. 111–124.

Kelly, B. P. 1981. Pelage polymorphism in Pacific harbor seals. Can. J. Zool. 59:1212–1219.

Kelly, B. P. 1988. Ringed seal, Phoca hispida. Pages 57-75 in J. W. Lentifer, editor. Selected Marine Mammal Species of Alaska: Species Accounts with Research and Management Recommendations. Marine Mammal Commission, Washington, D.C.

Kelly, B. P.1997. Behavior of ringed seals diving under shore-fast sea ice. Purdue University, Ann Arbour, MI. PhD thesis.

Kelly, B. P., J. L. Bengtson, P. Boveng, M. F. Cameron, S. P. Dahle, J. K. Jansen, E. A. Logerwell et al. 2010. Status review of the ringed seal (Phoca hispida). NOAA Tech. Memo. 250 pp.

Kelly, B. P., O. H. Badajos, M. Kunnasranta, J. R. Moran, M. Martinez-Bakker, D. Wartzok, and P. Boveng. 2010b. Seasonal home ranges and fidelity to breeding sites among ringed seals. Polar Biology 33: 1095–1109.

Kelly, B. P., J. J. Burns, and L. T. Quakenbush. 1988. Responses of ringed seals (Phoca hispida) to noise disturbance. Port Ocean Eng. Arctic Cond. 2:27–38.

Kelly, B. P., and L. T. Quakenbush. 1990. Spatiotemporal use of lairs by ringed seals (Phoca hispida). Can. J. Zool. 68:2503–2512.

Kelly, B. P., L. T. Quakenbush, and J. R. Rose. 1986. Ringed seal winter ecology and effects of noise disturbance. Outer Continental Shelf Environmental Assessment. Fairbanks, Alaska, University of Alaska.

Kelly, B. P., and D. Wartzok. 1996. Ringed seal diving behavior in the breeding season. Can. J. Zool. 74:1547–1555.

King, J.E. 1983. Seals of the world. 2nd ed. Comstock Publishing Associates, Ithaca, N.Y.

Kingsley, M. C., and I. Stirling. 1991. Haul-out behaviour of ringed and bearded seals in relation to defence against surface predators. Can. J. Zool. 69:1857–1861.

Kingsley, M. C. S. 1990. Status of the ringed seal, Phoca hispida, in Canada. Can. Field-Nat. 104:138–145.

Kingsley, M. C. S. 1998. The numbers of ringed seals (Phoca hispida) in Baffin Bay and associated waters, Pages 181–196 in M. P. Heide-Jørgensen, and C. Lydersen, eds., NAMMCO Scientific Publications. Tromso, Norway, North Atlantic Marine Mammal Commission.

Kingsley, M. C. S., and T. J. Byers. 1998. Failure of reproduction in ringed seals (Phoca hispida) in Amundsen Gulf, Northwest Territories in 1984–1987. NAMMCO Scientific Publications 1:197–210.

Kingsley, M. C. S., and N. J. Lunn. 1983. The abundance of seals in the eastern Beaufort Sea, northern Amundsen Gulf and Prince Albert Sound, 1982, Pages 16, Canadian Wildlife Service, Prepared for Dome Petroleum Limited, Gulf Canada Resources, Inc.

Kingsley, M. C. S., I. Stirling, and W. Calvert. 1985. The distribution and abundance of seals in the Canadian high Arctic, 1980-82. Can. J. Fish. Aquat. Sci. 42:1189–1210.

Kotierk, M. 2010. The Documentation of Inuit and Public Knowledge of Davis Strait Polar Bears, Climate Change, Inuit Knowledge and Environmental Management using Public Opinion Polls. Department of Environment, Government of Nunavut. vi + 96 pp.

Kovacs K. M. 1990. Mating strategies in male hooded seals (Cystophora cristata). Can. J. Zool. 68:2499–2502

Kovacs K. M.. 2007. Background document for development of a circumpolar ringed seal (Phoca hispida) monitoring plan. Marine Mammal Commission, Workshop to Develop Monitoring Plans for Arctic Marine Mammals. 45 p.

Kovacs K. M.. 2014. Circumpolar ringed seal (Pusa hispida) monitoring: CAFF's Ringed Seal Monitoring Network, Pages 45 pp. Tromso, Norsk Polarinstitutt.

Krafft, B. A., K. M. Kovacs, A. K. Frie, T. Haug, and C. Lydersen. 2006. Growth and population parameters of ringed seals (Pusa hispida) from Svalbard, Norway, 2002–2004. ICES J. Mar. Sci. 63:1136–1144.

Krafft, B. A., K. M. Kovacs, and C. Lydersen. 2007. Distribution of sex and age groups of ringed seals Pusa hispida in the fast-ice breeding habitat of Kongsfjorden, Svalbard. Mar. Ecol. Prog. Ser. 335:199–206.

Krupnik, I. I. 1988. Asiatic Eskimos and marine resources: a case of ecological pulsations or equilibrium? Arctic Anthropol. 25: 94–106.

Krupnik, I. 1993. The evolution of maritime hunting. Pages 185-215 in M. Levenson, editor. Arctic Adaptations, Native Whalers and Reindeer Herders of Northern Eurasia. University Press of New England, Hanover, MD and London, England. (Translated from Russian by M. Levenson, 355 p.).

Kucklick, J. R., M. M. Krahn, P. R. Becker, B. J. Porter, M. M. Schantz, G. S. York, T. M. O’Hara et al. 2006. Persistent organic pollutants in Alaskan ringed seal (Phoca hispida) and walrus (Odobenus rosmarus) blubber. J. Environ. Monitor. 8:848–854.

Kumlien, L. 1879. Mammals, Pages 55-61 Contributions to the Natural History of Arctic America made in connection with the Howgate Polar Expedition 1877–78. Washington, D.C., Government Printing Office.

Kunnasranta, M., H. Hyvärinen, J. Häkkinen, and J. T. Koskela. 2002. Dive types and circadian behaviour patterns of Saimaa ringed seals Phoca hispida saimensis during the open-water season. Acta Therio. 47:63–72.

Kwok, R., G. F. Cunningham, M. Wensnahan, I. Rigor, H. J. Zwally, and D. Yi. 2009. Thinning and volume loss of the Arctic Ocean sea ice cover: 2003–2008. J. Geophys. Res.: Oceans 114.

Laidler, G. J. 2006. Inuit and scientific perspectives on the relationship between sea ice and climate change: the ideal complement? Clim. Change 78:407–444.

Laidler, G. J., J. D. Ford, W. A. Gough, T. Ikummaq, A. S. Gagnon, S. Kowal, K. Qrunnut et al. 2009. Travelling and hunting in a changing Arctic: assessing Inuit vulnerability to sea ice change in Igloolik, Nunavut. Clim. Change 94:363–397.

Laidre, K. L., H. Stern, K. M. Kovacs, L. Lowry, S. E. Moore, E. V. Regehr, S. H. Ferguson et al. 2015. Arctic marine mammal population status, sea ice habitat loss, and conservation recommendations for the 21st century. Conserv. Biol. 29:724-737.

Laidre, K. L., I. Stirling, L. F. Lowry, Ø. Wiig, M. P. Heide-Jørgensen, and S. H. Ferguson. 2008. Quantifying the sensitivity of Arctic marine mammals to climate-induced habitat change. Ecol. Appl. 18:S97-S125.

Leclerc, L.-M. E., C. Lydersen, T. Haug, L. Bachmann, A. T. Fisk, and K. M. Kovacs. 2012. A missing piece in the Arctic food web puzzle? Stomach contents of Greenland sharks sampled in Svalbard, Norway. Polar Biol. 35:1197–1208.

Letcher, R.J., J.O. Bustnes, R. Dietz, B.M. Jenssen, E.H. Jorgensen, C. Sonne, J. Verreault, M.M. Vijayan and G.W. Gabrielsen, 2010. Exposure and effects assessment of persistent organohalogen contaminants in Arctic wildlife and fish. Science of the Total Environment, 408:2995–3043.

Liess, B., H.-R. Frey, and A. Zaghawa. 1989. Morbillivirus in seals: isolation and some growth characteristics in cell cultures. Deutsche tieriirztliche Wochenschrift 96: 180-182.

Lowry, L. F. 2016. Pusa hispida, Pages e. T41672A45231341, The IUCN Red List of Threatened Species 2016.

Lowry, L. F., and F. H. Fay. 1984. Seal eating by walruses in the Bering and Chukchi Seas. Polar Biol. 3:11–18.

Lowry, L. F., K. J. Frost, and J. J. Burns. 1980. Variability in the diet of ringed seals, Phoca hispida, in Alaska. Can. J. Fish. Aquat. Sci. 37:2254–2261.

Lucas, Z. N., and D. F. McAlpine. 2002. Extralimital occurrences of ringed seals, Phoca hispida, on Sable Island, Nova Scotia. Can. Field-Nat. 116:607–610.

Lunn, N. J., I. Stirling, and S. N. Nowicki. 1997. Distribution and abundance of ringed (Phoca hispida) and bearded seals (Erignathus barbatus) in western Hudson Bay. Can. J. Fish. Aquat. Sci. 54:914–921.

Luque, S. P., S. H. Ferguson, and G. A. Breed. 2014. Spatial behaviour of a keystone Arctic marine predator and implications of climate warming in Hudson Bay. J. Exper. Mar. Biol. Ecol. 461:504–515.

Lydersen, C. 1995. Energetics of pregnancy, lactation and neonatal development in ringed seals (Phoca hispida). Develop. Mar. Biol. 4:319–327.

Lydersen, C. 1991. Monitoring ringed seal (Phoca hispida) activity by means of acoustic telemetry. Can. J. Zool. 69:1178–1182.

Lydersen, C. 1998. Status and biology of ringed seals (Phoca hispida) in Svalbard, Pages 46–62 in M. P. Heide-Jørgensen, and C. Lydersen, eds. Ringed seals in the North Atlantic. Tromsø, The North Atlantic Marine Mammal Commission.

Lydersen, C., and I. Gjertz. 1986. Studies of the ringed seal (Phoca hispida Schreber 1775) in its breeding habitat in Kongsfjorden, Svalbard. Polar Res. 4:57–63.

Lydersen, C., and M. O. Hammill. 1993a. Activity, milk intake and energy consumption in free-living ringed seal (Phoca hispida) pups. J. Comp. Physiol. B: Biochem. Syst. Environ. Physiol. 163:433–438.

Lydersen, C., and M. O. Hammill. 1993b. Diving in ringed seal (Phoca hispida) pups during the nursing period. Can. J. Zool. 71:991–996.

Lydersen, C., M. O. Hammill, and M. S. Ryg. 1992. Water flux and mass gain during lactation in free-living ringed seal (Phoca hispida) pups. J. Zool. 228:361–369.

Lydersen, C., and K. M. Kovacs. 1999. Behaviour and energetics of ice-breeding, North Atlantic phocid seals during the lactation period. Mar. Ecol. Progr. Ser. 187:265–281.

Lydersen, C., and M. Ryg. 1991. Evaluating breeding habitat and populations of ringed seals Phoca hispida in Svalbard fjords. Polar Rec. 27:223–228.

Lydersen, C., and T. G. Smith. 1989. Avian predation on ringed seal Phoca hispida pups. Polar Biol. 9:489–490.

Lydersen, C., J. Vaquie-Garcia, E. Lydersen, G. N. Christensen, and K. M. Kovacs. 2017. Novel terrestrial haul-out behaviour by ringed seals (Pusa hispida) in Svalbard, in association with harbour seals (Phoca vitulina). Polar Res. 36:1, 1374124,

Macdonald, R. W., T. Hamer, J. Fyfe, H. Loeng, and T. Weingartner. 2003. AMAP Assessment 2002: The Influence of Global Change on Contaminant Pathways to, within, and from the Arctic. Arctic Monitoring and Assessment Programme (AMAP).

Mansfield, A. W. 1958, The biology of the Atlantic walrus Odobenus rosmarus rosmarus (Linnaeus) in the eastern Canadian Arctic. Arctic Unit, Fisheries Research Board of Canada.

Mansfield, A. W. 1967. Seals of arctic and eastern Canada. Bull. Fish. Res. Board Can. 137:1–35.

Mansfield, A. W. 1970. Population dynamics and exploitation of some Arctic seals. Pages 429–446 in M. W. Holdgate, editor. Antarctic Ecology. Academic Press, London, UK.

Marcoux, M., B. C. McMeans, A. T. Fisk, and S. H. Ferguson. 2012. Composition and temporal variation in the diet of beluga whales, derived from stable isotopes. Mar. Ecol. Progr. Ser. 471:283–291.

Marine Mammal Council. 2008. Russian Federation Government Decrees #1482-r, #1644-r, #1603-r, and #1551-r. Moscow, Russia, Marine Mammal Council.

Martin, J. W., M. M. Smithwick, B. M. Braune, P. F. Hoekstra, D. C. G. Muir, and S. A. Mabury. 2004. Identification of long-chain perfluorinated acids in biota from the Canadian Arctic. Environ. Sci. Tech. 38:373–380.

Martinez-Bakker, M. E., S. K. Sell, B. J. Swanson, B. P. Kelly, and D. A. Tallmon. 2013. Combined genetic and telemetry data reveal high rates of gene flow, migration, and long-distance dispersal potential in Arctic ringed seals (Pusa hispida). PLoS ONE 8:e77125.

Massie, G. N., M. W. Ware, E. N. Villegas, and M. W. Black. 2010. Uptake and transmission of Toxoplasma gondii oocysts by migratory, filter-feeding fish. Vet. Parasit. 169: 296–303.

Matley, J. K., A. T. Fisk, and T. A. Dick. 2015. Foraging ecology of ringed seals (Pusa hispida), beluga whales (Delphinapterus leucas) and narwhals (Monodon monoceros) in the Canadian High Arctic determined by stomach content and stable isotope analysis. Polar Res. 34:24295.

McClelland, G. 1980. Phocanema decipiens: growth, reproduction, and survival in seals. Experim. Parasit. 49: 175–187.

McLaren, I. A. 1958a. The biology of the ringed seal (Phoca hispida Schreber) in the eastern Canadian Arctic. Ottawa, Fisheries Research Board of Canada. 97 pp.

McLaren, I. A. 1958b. The economics of seals in the eastern Canadian Arctic. Montreal, Fisheries Research Board of Canada. 94 pp.

McLaren, I. A. 1962. Population dynamics and exploitation of seals in the eastern Canadian Arctic, Pages 168-183 in E. D. Le Cren, and M. W. Holdgate, eds. The exploitation of natural animal populations. Oxford, Blackwell Scientific Publications.

McLaren, I. A.1966. Analysis of an aerial census of ringed seals. J. Fish. Res. Board Can. 23:769–773.

McLaren, I. A.1990. Pinnipeds and Oil: Ecologic Perspectives. Pages 42–119 in: Geraci, J. R., and D. J. St. Aubin, Synthesis of Effects of Oil on Marine Mammals. OCS Study MMS 88-0049. Department of Interior, Minerals Management Service, Atlantic OCS Region.

McMeans, B. C., J. Svavarsson, S. Dennard, and A. T. Fisk. 2010. Diet and resource use among Greenland sharks (Somniosus microcephalus) and teleosts sampled in Icelandic waters, using δ13C, δ15N, and mercury. Can. J. Fish. Aquat. Sci. 67:1428–1438.

Measures, L. N., J.-F. Gosselin, and E. Bergeron. 1997. Heartworm, Acanthocheilonema spirocauda (Leidy, 1858), infections in Canadian phocid seals. Can. J. Fish. Aquat. Sci. 54: 842–846.

Measures, L. N., J. P. Dubey, P. Labelle, and D. Martineau. 2004. Seroprevalence of Toxoplasma gondii in Canadian pinnipeds. J. Wildl. Dis. 40: 294-300.

Meier, W. N., G. K. Hovelsrud, B. E. H. Oort, J. R. Key, K. M. Kovacs, C. Michel, C. Haas et al. 2014. Arctic sea ice in transformation: A review of recent observed changes and impacts on biology and human activity. Rev. Geophys. 52:185–217.

Melnikov, V. V., I. A. Zagrebin, G. M. Zelensky, and L. I. Ainana. 2007. Killer whales (Orcinus orca) in waters adjacent to the Chukotka Peninsula, Russia. J. Cet. Res. Manage. 9:53–63.

Merkel, F., D. Boertmann, A. Mosbech, and F. Ugarte (eds). 2012. The Davis Strait. A preliminary strategic environmental impact assessment of hydrocarbon activities in the eastern Davis Strait. Aarhus University, DCE – Danish Centre for Environment and Energy, 280 pp. [Scientific Report from DCE – Danish Centre for Environment and Energy No. 15.].

Mikaelian, I., D. Leclair, and J. Inukpuk. 2001. Adenocarcinoma of the small intestine in a ringed seal from Hudson Bay. J.Wildl. Dis. 37: 379–382.

Miller, G. W., R. A. Davis, and K. J. Finley. 1982. Ringed seals in the Baffin Bay region: habitat use, population dynamics and harvest levels, Pages 94, Report Arctic Pilot Project. Toronto, Canada, LGL Limited.

Miller, M. A., W. A. Miller, P. A. Conrad, E. R. James, A. C. Mell, C. M. Leutenegger, H. A. Dabritz, A. E. Packham, D. Paradies, M. Harris, J. Ames, D. A. Jessup, K. Worcester, M. E. Grigg. 2008. Type X Toxoplasma gondii in a wild mussel and terrestrial carnivores from coastal California: new linkages between terrestrial mammals, runoff and toxoplasmosis of sea otters. Int. J. Parasit. 38(11): 1319–1328.

Miller, M. A., B. A. Byrne, S. S. Jang, E. M. Dodd, E. Dorfmeier, M. D. Harris, J. Ames, D. Paradies, K. Worcester, D. A. Jessup, and W. A. Miller. 2010. Enteric bacterial pathogen detection in southern sea otters (Enhydra lutris nereis) is associated with coastal urbanization and freshwater runoff. Vet. Res. 41(1): 01.

Mineev, V. N. 1981. Protection and regulation of the harvest of marine mammals in the Bering and Chukchi seas. Pages 101-102 in L. A. Popov, editor. Scientific investigations of the Marine Mammals of the North Pacific Ocean in 1980/81. VNIRO, Moscow, Russia. (Translated from Russian, 3 p.).

Mineev, V. N. 1984. Protection and regulation of the harvest of marine mammals in the Bering and Chukchi seas. Pages 76-78 in L. A. Popov, editor. Scientific Investigations of the Marine Mammals of the North Pacific Ocean in 1982/83. VNIRO, Moscow, Russia. (Translated from Russian by S. Pearson, 6 p.).

Miyazaki, N. 2002. Ringed, Caspian, and Baikal seals Pusa hispida, P. caspica, and P. sibirica. In: W. F. Perrin;B. Wursig;J. G. M. Thewissen (ed.), Encyclopedia of Marine Mammals, pp. 1033–1037. Academic Press.

Mosbech, A., D. Boertmann, and M. Jespersen. 2007: Strategic Environmental Impact Assessment of hydrocarbon activities in the Disko West area. National Environmental Research Institute, University of Aarhus. 188 pp. [NERI technical report no. 618;]

Moulton, V. D., W. J. Richardson, R. E. Elliott, T. L. Mcdonald, C. Nations, and M. T. Williams. 2005. Effects of an offshore oil development on local abundance and distribution of ringed seals (Phoca hispida) of the Alaskan Beaufort Sea. Mar. Mam. Sci. 21:217–242.

Muir, D. C. G., B. Braune, B. G. E. De March, R. Norstrom, R. Wagemann, L. Lockhart, B. T. Hargrave et al. 1999. Spatial and temporal trends and effects of contaminants in the Canadian Arctic marine ecosystem: a review. Sci. Total Environ. 230:83–144.

Muir, D. C. G., R. J. Norstrom, and M. Simon. 1988. Organochlorine contaminants in Arctic marine food chains: accumulation of specific polychlorinated biphenyls and chlordane-related compounds. Environ. Sci. Tchn. 22:1071–1079.

Muir, D. C. G., R. Wagemann, B. T. Hargrave, D. J. Thomas, D. B. Peakall, and R. J. Norstrom. 1992. Arctic marine ecosystem contamination. Sci. Total Environ. 122:75–134.

Muto, M. M., V. T. Helker, R. P. Angliss, B. A. Allen, P. L. Boveng, J. M. Breiwick, M. F. Cameron, P. J. Clapham, S. P. Dahle, M. E. Dahlheim, B. S. Fadely, M. C. Ferguson, L. W. Fritz, R. C. Hobbs, Y. V. Ivashchenko, A. S. Kennedy, J. M. London, S. A. Mizroch, R. R. Ream, E. L. Richmond, K. E. W. Shelden, R. G. Towell, P. R. Wade, J. M. Waite, and A. N. Zerbini. 2017. Alaska marine mammal stock assessments, 2016. U.S. Dep. Commer., NOAA Tech. Memo. NMFS-AFSC-355, 366 p. doi:10.7289/V5/TM-AFSC-355.

Nguyen, L., N. W. Pilfold, A. E. Derocher, I. Stirling, A. M. Bohart, and E. Richardson. 2017. Ringed seal (Pusa hispida) tooth annuli as an index of reproduction in the Beaufort Sea. Ecol. Indicat. 77:286–292.

Nielsen, O., K. Nielsen, and R. E. A. Stewart. 1996. Serologic evidence of Brucella spp. exposure in Atlantic walruses (Odobenus rosmarus rosmarus) and ringed seals (Phoca hispida) of Arctic Canada. Arctic 49: 383–386.

NIRB (Nunavut Impact Review Board). 2012. NIRB Project Certificate [No.: 005]. NIRB File No. 08MN053, December 28, 2012. Nunavut Impact Review Board, Cambridge Bay, NU.

NIRB (Nunavut Impact Review Board). 2014. NIRB Project Certificate [No.: 005, Amendment 1] (Amendment of Project Certificate to reflect modifications to the Project associated with the Early Revenue Phase), May 28, 2014, Nunavut Impact Review Board, Cambridge Bay, NU.

NIRB (Nunavut Impact Review Board). 2015. Comment Request on the Applicability of the previously issued Guidelines for the Mary River Project to Baffinland’s Phase 2 Development project proposal. Nunavut Impact Review Board File No. 08MN053. Cambridge Bay, NU.

NOAA (National Oceanic and Atmospheric Administration). 2012. NOAA lists ringed and bearded ice seal populations under the Endangered Species Act: Loss of ice and snow cover are most significant conservation concerns. 21 December 2012.

Nyakatura, K., and O. R. P. Bininda-Emonds. 2012. Updating the evolutionary history of Carnivora (Mammalia): a new species-level supertree complete with divergence time estimates. BMC Biol. 10:12.

Nyman, T., M. Valtonen, J. Aspi, M. Ruokonen, M. Kunnasranta, and J. U. Palo. 2014. Demographic histories and genetic diversities of Fennoscandian marine and landlocked ringed seal subspecies. Ecol. Evol. 4:3420–3434.

Nymo, I.H., R. Rodven, K. Beckmen, A. K. Larsen, M. Tryland, L. Quakenbush, and J. Godfroid. Brucella Antibodies in Alaskan True Seals and Eared Seals–Two Different Stories. Front. Vet. Sci. 5:8.

Olson, M. E., P. D. Roach, M. Stabler, and W. Chan. 1997. Giardiasis in ringed seals from the western Arctic. J. Wildl. Dis. 33(3): 646–648.

Onderka, D. K. 1989. Prevalence and pathology of nematode infections in the lungs of ringed seals (Phoca hispida) of the western arctic of Canada. J. Wildl. Dis. 25: 218–224.

Øritsland, N. A., and K. Ronald. 1973. Effects of solar radiation and windchill on skin temperature of the harp seal, Pagophilus groenlandicus (Erxleben, 1777). Comp. Biochem. Physiol.Part A: Physiol. 44:519–525.

Øritsland, N. A., and K. Ronald. 1978. Aspects of temperature regulation in harp seal pups evaluated by in vivo experiments and computer simulations. Acta Physiol. 103:263–269.

Orr, J. C., V. J. Fabry, O. Aumont, L. Bopp, S. C. Doney, R. A. Feely, A. Gnanadesikan et al. 2005. Anthropogenic ocean acidification over the twenty-first century and its impact on calcifying organisms. Nature 437:681–686.

Osterhaus, A. D. M. E., J. Groen, P. Vries, F. G. M. C. UytdeHaag, B. Klingeborn, and R. Zarnke. 1988. Canine distemper virus in seals. Nature 335: 403–404.

Outridge, P. M., K. A. Hobson, and J. M. Savelle. 2009. Long-term changes of mercury levels in ringed seal (Phoca hispida) from Amundsen Gulf, and beluga (Delphinapterus leucas) from the Beaufort Sea, western Canadian Arctic. Sci. Total Environ. 407:6044–6051.

Overland, J. E., and M. Wang. 2013. When will the summer Arctic be nearly sea ice free? Geophys. Res. Let. 40:2097–2101.

Palo, J., H. S. Mäkinen, E. Helle, S. O., and R. Väinölä. 2001. Microsatellite variation in ringed seals (Phoca hispida): genetic structure and history of the Baltic Sea population. Hered. 86:609–617.

Pamperin, N. J., E. H. Follmann, and B. T. Person. 2008. Sea-ice use by Arctic foxes in northern Alaska. Polar Biol. 31:1421.

Parkinson, C. L. 2014. Spatially mapped reductions in the length of the Arctic sea ice season. Geophysical Research Letters 41:4316–4322.

Parkinson, C. L., and D. J. Cavalieri. 2002. A 21 year record of Arctic sea-ice extents and their regional, seasonal and monthly variability and trends. Annals Glaciol 34:441–446.

Paterson, W., C. E. Sparling, D. Thompson, P. P. Pomeroy, J. I. Currie, and D. J. McCafferty. 2012. Seals like it hot: Changes in surface temperature of harbour seals (Phoca vitulina) from late pregnancy to moult. J Thermal Biol. 37:454–461.

Pelly, D. F. 2001. Sacred Hunt: A Portrait of the Relationship between Seals and Inuit. University of Washington Press, Seattle, WA.

Petersen, S. D. 2008. Spatial genetic patterns of Arctic mammals: Peary caribou (Rangifer tarandus pearyi), polar bear (Ursus maritimus), and ringed seal (Pusa [=Phoca] hispida). Ph.D. thesis, Trent University, Peterborough, Ontario.

Petersen, S. D., M. Hainstock, and P. J. Wilson. 2010. Population genetics of Hudson Bay marine mammals: current knowledge and future risks, Pages 237–265 in S. H. Ferguson, L. Lisetto, and M. Mallory, eds. A little less Arctic: changes to top predators in the world's largest nordic inland sea, Hudson Bay, Springer.

Pianka, E. R. 1988, Evolutionary ecology. New York, Harper and Row.

Pilfold, N. W., A. E. Derocher, I. Stirling, and E. Richardson. 2014. Polar bear predatory behaviour reveals seascape distribution of ringed seal lairs. Pop. Ecol. 56:129–138.

Piugattuk, N. 1990. Interview IE-136. Igloolik, Nunavut, Archives of the Inullariit Society, Igloolik Research Centre.

Pörtner, H. O. 2008. Ecosystem effects of ocean acidification in times of ocean warming: a physiologist’s view. Mar. Ecol. Progr. Ser. 373:203–217.

Pörtner, H. O., M. Langenbuch, and A. Reipschläger. 2004. Biological impact of elevated ocean CO2 concentrations: lessons from animal physiology and earth history. J. Oceanog. 60:705–718.

Popov, L. A. 1982. Status of the main ice-living seals inhabiting inland waters and coastal marine areas of the USSR. Pages 361-381 in FAO Fisheries Series No. 5. Mammals in the Seas. Volume IV - Small Cetaceans, Seals, Sirenians and Otters. Food and Agriculture Organization of the United Nations, Rome, Italy.

Post, E., M. C. Forchhammer, M. S. Bret-Harte, T. V. Callaghan, T. R. Christensen, B. Elberling, A. D. Fox et al. 2009. Ecological Dynamics Across the Arctic Associated with Recent Climate Change. Science 325:1355–1358.

Priest, H., and P. J. Usher. 2004. Nunavut wildlife harvest study. Iqaluit, Nunavut Wildlife Management Board. 816 pp.

Pritchard J. K., M. Stephens, and P. Donnelly. 2000. Inference of population structure using multilocus genotype data. Genetics. 155: 945–959

QIA (Qikiqtani Inuit Association). 2012. Qikiqtani Inuit Association’s final written submission for Baffinland Iron Mines Corporation, Mary River Project, Final Environmental Impact Statement. Submitted May 30th, 2012 to the Nunavut Impact Review Board (NIRB), Cambridge Bay, NU. 40 pp + appendices.

QIA (Qikiqtani Inuit Association). 2013. Qikiqtani Inuit Association’s Technical Review Submission for Baffinland Iron Mines Corporation, Mary River Project, Addendum to the Final Environmental Impact Statement. Submitted October 18, 2013 to the Nunavut Impact Review Board (NIRB), Cambridge Bay, NU. 176 pp.

QIA (Qikiqtani Inuit Association). 2014. Qikiqtani Inuit Association’s final written submission for Baffinland Iron Mines Corporation, Mary River Project, Addendum to the Final Environmental Impact Statement. Submitted January 13, 2014 to the Nunavut Impact Review Board (NIRB), Cambridge Bay, NU. 110 pp.

Quakenbush, L. T. 2007. Polybrominated diphenyl ether compounds in ringed, bearded, spotted, and ribbon seals from the Alaskan Bering Sea. Mar. Poll. Bull. 54:226–246.

Quakenbush, L. T, and J. J. Citta. 2008. Perfluorinated contaminants in ringed, bearded, spotted, and ribbon seals from the Alaskan Bering and Chukchi Seas. Mar. Poll. Bull. 56:1802–1814.

Quakenbush L. 2015. Ice Seal Monitoring in the Bering-Chukchi Sea Region. Unpublished Report to National Marine Fisheries Service for #NA11NMF4390200.

Ramsay, M. A., and I. Stirling. 1988. Reproductive biology and ecology of female polar bears (Ursus maritimus). J. Zool. (Lond.) 214:601-634.

Raven, J., K. Caldeira, H. Elderfield, O. Hoegh-Guldberg, P. Liss, U. Riebesell, J. Shepherd et al. 2005, Ocean acidification due to increasing atmospheric carbon dioxide. The Royal Society Policy document 12/05.

Red Data Book. 2001. Red data book of the Russian Federation. Moscow: Astrel Publishers.

Reeves, R. R. 1998. Distribution, abundance and biology of the ringed seal (Phoca hispida) in the Arctic, Pages 9–45 in M. P. Heide-Jørgensen, and C. Lydersen, eds. Ringed seals (Phoca hispida) in the North Atlantic, North Atlantic Marine Mammal Commission (NAMMCO)

Reeves, R. R., G. W. Wenzel, and M. C. S. Kingsley. 1998. Catch history of ringed seals (Phoca hispida) in Canada, Pages 100–129 in M. P. Heide-Jørgensen, and C. Lydersen, eds., Ringed seals in the North Atlantic. Tromsø, Norway, NAMMCO Scientific Publications.

Reidman, M. 1990. The Pinnipeds: Seals, Sea Lions, and Walruses. University of California Press, Berkeley, CA.

Reimer, J.R., H. Caswell, A.E. Derocher and M.A. Lewis (2019). Ringed seal demography in a changing climate. Ecological Applications, 29(3), e01855, 1–16.

Riewe, R.R. 1977. The utilization of wildlife in the Jones Sound region by the Grise Fiord Inuit. Pages 623–644 in: L. C. Bliss (ed.), Truelove Lowland, Devon Island, Canada: A High Arctic Ecosystem. University of Alberta Press, Edmonton AB. 714 pp.

Rice, D. W. 1998. Marine Mammals of the World, Pages 231. Lawrence, Society of Marine Mammalogy.

Richardson, W. J., C. R. Greene Jr, C. I. Malme, and D. H. Thomson. 1995, Marine mammals and noise. San Diego, CA, Academic Press, Inc.

Ridoux, V., A. J. Hall, G. Steingrimsson, and G. Olafsson. 1998. An inadvertent homing experiment with a young ringed seal, Phoca hispida. Mar. Mam. Sci. 14:883–888.

Rigét, F., and R. Dietz. 2000. Temporal trends of cadmium and mercury in Greenland marine biota. Sci. Total Environ. 245:49–60.

Rigét, F., R. Dietz, K. Vorkamp, P. Johansen, and D. C. G. Muir. 2004. Levels and spatial and temporal trends of contaminants in Greenland biota: an updated review. Sci. Total Environ. 331:29–52.

Rigét, F., D. Muir, M. Kwan, T. Savinova, M. Nyman, V. Woshner and T. O’Hara. 2005. Circumpolar pattern of mercury and cadmium in ringed seals. Sci. Total Environ. 351–352:312–322.

Rigét, F., A. Bignert, B. Braune, M. Dam, R. Dietz, M. Evans, N. Green, H. Gunnlaugsdóttir, J. Kucklick, R.J. Letcher, D. Muir, S. Schuur, C. Sonne, G. Stern, G. Tomy, K. Vorkamp, S. Wilson. 2018. A status of temporal trends of persistent organic pollutants in Arctic biota. Sci. Total Environ. Accepted August 2018.

Robertson, L. J. 2007. The potential for marine bivalve shellfish to act as transmission vehicles for outbreaks of protozoan infections in humans: a review. Int. J. Food Microbiol. 12: 201–216.

Rosing-Asvid, A. 2010. Seals of Greenland. Ilinniusiorfik Undervisningsmiddelforlag, Nuuk, Greenland. 144 pp.

Roth, J. D. 2002. Temporal variability in arctic fox diet as reflected in stable-carbon isotopes; the importance of sea ice. Oecologia 133:70–77.

Roth, J. D. 2003. Variability in marine resources affects Arctic fox population dynamics. J. Anim. Ecol. 72:668–676.

Ryg, M., T. G. Smith, and N. A. Øritsland. 1988. Thermal significance of the topographical distribution of blubber in ringed seals (Phoca hispida). Can. J. Fish. Aquat. Sci. 45:985–992.

Ryg, M., T. G. Smith, and N. A. Øritsland. 1990. Seasonal changes in body mass and body composition of ringed seals (Phoca hispida) on Svalbard. Can. J. Zool. 68:470–475.

Ryg, M. S., Y. Solberg, C. Lydersen, and T. G. Smith. 1992. The scent of rutting male ringed seals (Phoca hispida). J. Zool. 226:681–689.

Schusterman, R. J., D. Kastak, D. H. Levenson, C. J. Reichmuth, and B. L. Southall. 2000. Why pinnipeds don’t echolocate. J. Acous. Soc. Am. 107:2256–2264

Serreze, M. C., M. M. Holland, and J. Stroeve. 2007. Perspectives on the Arctic's shrinking sea-ice cover. Science 315:1533–1536.

Shannon, K.A., and M.M.R. Freeman. 2009. Inuit Observations of Polar Bears in Salliq/Coral Harbour, Nunavut and the Management of the Conservation Hunt. In Freeman, Milton M.R. and Lee Foote (eds.). Inuit, Polar Bears and Sustainable Use: Local, National and International Perspectives. Edmonton: CCI Press, pp. 39–50.

Siegstad, H., P. B. Neve, M. P. Heide-Jørgensen, and T. Härkönen. 1998. Diet of the ringed seal (Phoca hispida) in Greenland, Pages 299–241 in M. P. Heide-Jørgensen, and C. Lydersen, eds. Ringed seals (Phoca hispida) in the North Atlantic. North Atlantic Marine Mammal Commission (NAMMCO).

Sills, J. M., B. L. Southall, and C. Reichmuth. 2015. Amphibious hearing in ringed seals (Pusa hispida): underwater audiograms, aerial audiograms and critical ratio measurements. J. Experim. Biol. 218:2250–2259.

Simon, A., M. Chambellant, B. J. Ward, M. Simard, J. F. Proulx, B. Levesque, M. Bigras-Poulin, A. N. Rousseau, and N. H. Ogden. 2011. Spatio-temporal variations and age effect on Toxoplasma gondii seroprevalence in seals from the Canadian Arctic. Parasit. 138:1362–1368.

Simpkins, M. A., L. M. Hiruki-Raring, G. Sheffield, J. M. Grebmeier, and J. L. Bengtson. 2003. Habitat selection by ice-associated pinnipeds near St. Lawrence Island, Alaska in March 2001. Polar Biol. 26:577–586.

Simpkins, M. A., B. P. Kelly, and D. Wartzok. 2001. Three-dimensional diving behaviors of ringed seals (Phoca hispida). Mar. Mam. Sci. 17:909–925.

Sipilä, T. 2016a. Pusa hispida ssp. ladogensis, Pages e.T41674A66991648, The IUCN Red List of Threatened Species 2016.

Sipilä, T. 2016b. Pusa hispida ssp. saimensis, Pages e.T41675A66991678, The IUCN Red List of Threatened Species 2016.

Skura, E. 2016. Nunavut seismic testing appeal could help define Canada's duty to consult Indigenous groups: Clyde River's case will be heard by the Supreme Court of Canada later this month. CBC News, Nov 21, 2016. Website

Slavik, D. 2013. Knowing Nanuut: Bankslanders Knowledge and Indicators of Polar Bear Population Health. Master of Science in Rural Sociology thesis, University of Alberta, Edmonton, AB.

Smith, T. G. 1973. Population dynamics of the ringed seal in the Canadian Eastern Arctic Can. Bull. Fish. Res. Bd Can. 181: 55 pp.

Smith, T. G.1975. Ringed seals in James Bay and Hudson Bay: population estimates and catch statistics. Arctic 28:170–182.

Smith, T. G. 1976. Predation of ringed seal pups (Phoca hispida) by the arctic fox (Alopex lagopus). Can. J. Zool. 54:1610–1616.

Smith, T. G.1979. How Inuit trapper-hunters make ends meet. Can. Geog. 99(3): 56–61.

Smith, T. G. 1980. Polar bear predation of ringed and bearded seals in the land-fast sea ice habitat. Can. J. Zool. 58:2201–2209.

Smith, T. G. 1987. The ringed seal, Phoca hispida, of the Canadian Western Arctic. Can. Bull. Fish. Aquat. Sci. 216: 81 p.

Smith, T. G., and J. R. Geraci. 1975. The effect of contact and ingestion of crude oil on ringed seals of the Beaufort Sea. Tech. Rep. Beaufort Sea Proj.

Smith, T. G., and M. O. Hammill. 1981. Ecology of the ringed seal, Phoca hispida, in its fast ice breeding habitat. C. J. Zool. 59:966–981.

Smith, T. G., M. O. Hammill, D. W. Doidge, T. Cartier, and G. A. Selno. 1979. Marine mammal studies in southeastern Baffin Island. Calgary, Alberta, Final report to the Eastern Arctic Marine Environmental Studies (EAMES) project.

Smith, T. G., M. O. Hammill, and G. Taugbøl. 1991. A review of the developmental, behavioural and physiological adaptations of the ringed seal, Phoca hispida, to life in the Arctic winter. Arctic 44:124–131.

Smith, T. G., and C. Lydersen. 1991. Availability of suitable land-fast ice and predation as factors limiting ringed seal populations, Phoca hispida, in Svalbard. Polar Res. 10:585–594.

Smith, T. G., and I. Stirling. 1975. The breeding habitat of the ringed seal (Phoca hispida). The birth lair and associated structures. Can. J. Zool. 53:1297–1305.

Smith, T. G., and I. Stirling.1978. Variation in the density of ringed seal (Phoca hispida) birth lairs in the Amundsen Gulf, Northwest Territories. Can. J. Zool. 56:1066–1070.

Smith, T. G., and D. Taylor. 1977. Notes on marine mammal, fox and polar bear harvests in the Northwest Territories 1940 to 1972, Pages 37 pp., Fisheries and Marine Service Technical Report 694, Arctic Biological Station, Fisheries and Marine Service, Department of Fisheries and the Environment.

Sołtysiak, Z., M. Simard, and J. Rokicki. 2013. Pathological changes of stomach in ringed seal (Pusa hispida) from Arviat (North Canada) caused by anisakid nematodes. Polish J. Vet. Sci. 16(1): 63–67.

Soper, J. D. 1944. The mammals of southern Baffin Island, Northwest Territories, Canada. J. Mamm. 25:221–254.

Southall, B. L., A. E. Bowles, W. T. Ellison, J. J. Finneran, R. L. Gentry, C. R. Greene, D. Kastak et al. 2007. Marine mammal noise exposure criteria: initial scientific recommendations. Aquat. Mam. 33:411–521.

Stephenson, S.A. 2004. Harvest studies in the Inuvialuit Settlement Region, Northwest Territories, Canada: 1999 and 2001–2003. Can. Manusc. Rep. Fish. Aquat. Sci. 2700. vi + 34 p.

Stern, H. L., and K. L. Laidre. 2016. Sea-ice indicators of polar bear habitat. The Cryosphere 10:2027.

Stewart, D. B., and K. L. Howland. 2009. An ecological and oceanographical assessment of the alternate ballast water exchange zone in the Hudson Strait region. DFO Can. Sci. Advis. Sec. Res. Doc. 2009/008. vii + 89 p.

Stewart, E. J., S. E. L. Howell, D. Draper, J. Yackel, and A. Tivy. 2007. Sea ice in Canada's Arctic: Implications for cruise tourism. Arctic 60:370–380.

Stewart, R. E. A., P. Richard, M. C. S. Kingsley, and J.J. Houston. 1986. Seals and sealing in Canada's northern and Arctic regions. Can. Tech. Rep. Fish. Aquat. Sci. 1463. 31 pp.

Stewart, E. J., A. Tivy, S. E. L. Howell, J. Dawson, and D. Draper. 2010. Cruise tourism and sea ice in Canada's Hudson Bay region. Arctic 63:57–66.

Stirling, I. 1973. Vocalization in the ringed seal (Phoca hispida). J. Fish. Res. Bd. Can. 30:1592–1594.

Stirling, I.1974. Midsummer observations on the behavior of wild polar bears (Ursus maritimus). Can. J. Zool. 52:1191–1198.

Stirling, I. 1977. Adaptations of Weddell and ringed seals to exploit the polar fast ice habitat in the absence or presence of surface predators. Pages 26–30 in: G. A. Llano (ed.), Adaptations within Antarctic Ecosystems: Proceedings of the Third SCAR (Scientific Committee on Antarctic Research) Symposium on Antarctic Biology.

Stirling, I. 2002. Polar bears and seals in the eastern Beaufort Sea and Amundsen Gulf: a synthesis of population trends and ecological relationships over three decades. Arctic 55:59–76.

Stirling, I., and W. R. Archibald. 1977. Aspects of predation of seals by polar bears. J. Fish. Res. Bd Can. 34:1126–1129.

Stirling, I., W. R. Archibald, and D. DeMaster. 1977. Distribution and abundance of seals in the eastern Beaufort Sea. J. Fish. Res. Bd Can. 34:976–988.

Stirling, I., D. Andriashek, P. Latour, and W. Calvert. 1975. The distribution and abundance of polar bears in the eastern Beaufort Sea. Final Report to the Beaufort Sea Project. Victoria, B.C.: Fisheries and Marine Service, Department of Environment. 59 p.

Stirling, I. and W, Calvert. 1979. Ringed Seal. Pp. 66–69 in: Mammals in the Seas, Vol. II pinniped species summaries and report on sirenians. FAO Fisheries Series No. 5 Food and Agriculture Organization of the United Nations, Rome.

Stirling, I., W. Calvert, and H. Cleator. 1983. Underwater vocalizations as a tool for studying the distribution and relative abundance of wintering pinnipeds in the High Arctic. Arctic 36:262–274.

Stirling, I., H. Cleator, and T. G. Smith. 1981. Marine mammals, Pages 45–58 in I. Stirling, and H. Cleator, eds., Polynyas in the Canadian Arctic. Ottawa (Canadian Wildlife Service, Occasional paper, 45)

Stirling, I., and A. E. Derocher. 1993. Possible impacts of climatic warming on polar bears. Arctic 46:240–245.

Stirling, I., M. Kingsley, and W. Calvert. 1982. The distribution and abundance of seals in the eastern Beaufort Sea, 1974–79, Environment Canada, Canadian Wildlife Service.

Stirling, I., and P. B. Latour. 1978. Comparative hunting abilities of polar bear cubs of different ages. Can. J. Zool. 56:1768–1772.

Stirling, I., and E. H. McEwan. 1975. The caloric value of whole ringed seals (Phoca hispida) in relation to polar bear (Ursus maritimus) ecology and hunting behavior. Can. J. Zool. 53:1021–1027.

Stirling, I., and N. A. Øritsland. 1995. Relationships between estimates of ringed seal (Phoca hispida) and polar bear (Ursus maritimus) populations in the Canadian Arctic. Can. J. Fish. Aquat. Sci. 52:2594–2612.

Stirling, I., and J. A. Thomas. 2003. Relationships between underwater vocalizations and mating systems in phocid seals. Aquat. Mamm. 29.2:227–246.

Stroeve, J. C., M. C. Serreze, M. M. Holland, J. E. Kay, J. Malanik, and A. P. Barrett. 2012. The Arctic’s rapidly shrinking sea ice cover: a research synthesis. Clim. Change 110:1005–1027.

Sundqvist, L., T. Harkonen, C. J. Svensson, and K. C. Harding. 2012. Linking climate trends to population dynamics in the Baltic ringed seal: Impacts of historical and future winter temperatures. Ambio 41:865–872.

Swenson, J.E., A. Bjørge, K. Kovacs, P.O. Syvertsen, A. Wiig, and A. Zedrosser. 2010. Mammalia, pp. 431–439. In J.A. Kålås, Å. Viken, S. Henriksen, and S. Skjelseth (eds.). The 2010 Norwegian Red List for Species. Norwegian Biodiversity Information Centre, Trondheim, Norway.

Taugbøl, G. 1984. Ringed seal thermoregulation, energy balance and development in early life, a study on Pusa hispida in Kongsfd, Svalbard, Thesis, Zoofysiologisk Institutt, University of Oslo, Norway (Can. Transl. Fish. Aquat. Sci. 5090).

Teilmann, J., E. W. Born, and M. Acquarone. 1999. Behaviour of ringed seals tagged with satellite transmitters in the North Water polynya during fast-ice formation. Can. J. Zool. 77:1934–1946.

Teilmann, J., and F. O. Kapel. 1998. Exploitation of ringed seals (Phoca hispida) in Greenland, Pages 130–151 in M. P. Heide-Jørgensen, and C. Lydersen, eds., Ringed seals in the North Atlantic. Tomso, Norway, NAMMCO Scientific Publication.

Tenter, A. M., A. R. Heckeroth, and L. M. Weiss. 2000. Toxoplasma gondii: from animals to humans. Int. J. Parasit. 30: 1217–1258.

Thewissen, J. G. M. and S. Nummela. 2008. Sensory Evolution on the Threshold: Adaptations in Secondarily Aquatic Vertebrates. University of California Press, San Diego.

Thiemann, G. W., A. E. Derocher, and I. Stirling. 2008. Polar bear Ursus maritimus conservation in Canada: an ecological basis for identifying designatable units. Oryx 42:504–515.

Tikhomirov, E. A. 1968. Body growth and development of reproductive organs of the North Pacific phocids, Pages 213–241 in V. A. Arsen'ev, and K. I. Panin, eds., Pinnipeds of the North Pacific. Moscow, Russia, Pischevaya Promyshlennost (Food Industry).

Tryland, M., L. Kleivane, A. Alfredsson, M. Kjeld, A. Arnason, S. Stuen, and J. Godfroid. 1999. Evidence of Brucella infection in marine mammals in the North Atlantic Ocean. Vet. Rec. 144:588–592.

Tynan, C. T., and D. P. DeMaster. 1997. Observations and predictions for Arctic climate change: potential effects on marine mammals. Arctic 50:308–322.

USGS (United States Geological Survey) 2008. Circum-Arctic resource appraisal: estimates of undiscovered oil and gas north of the Arctic Circle, Fact sheet 2008-3049. Menlo Park, CA., U.S. Geological Survey.

Vibe, C. 1950. The marine mammals and the marine fauna in the Thule district (northwest Greenland) with observations on ice conditions in 1939–41. Trichinosis in arctic mammals. Medd. om Grønland. 150:93–97.

Vincent-Chambellant, M. 2010. Ecology of ringed seals (Phoca hispida) in western Hudson Bay, Canada, University of Manitoba, Winnipeg, MB.

Voorhees, H., R Sparks, H.P. Huntington, and K.D. Rode. 2014. Traditional knowledge about Polar Bears (Ursus maritimus) in northwestern Alaska. Arctic 67(4):523–536.

Wagemann, R., S. Innes, and P. R. Richard. 1996. Overview and regional and temporal differences of heavy metals in Arctic whales and ringed seals in the Canadian Arctic. Sci. Total Environ. 186:41–66.

Wagemann, R., and D. C. G. Muir. 1984, Concentrations of heavy metals and organochlorines in marine mammals of northern waters: overview and evaluation. Can. Tech. Rep. Fish. Aquat. Sci 1279. 103 pp.

Walsh, J. E. 2008. Climate of the Arctic marine environment. Ecol. Appl. 18:S3-S22.

Waring, G. T., R. M. Pace, J. M. Quintal, C. P. Fairfield, and K. Maze-Foley. 2004. US Atlantic and Gulf of Mexico marine mammal stock assessments–2003. NOAA Tech. Memo. NMFS-NE 182:287.

Wartzok, D., S. Sayegh, H. Stone, J. Barchak, and W. Barnes. 1992. Acoustic tracking system for monitoring under-ice movements of polar seals. J. Acous. Soc. Am. 92:682–687.

Wathne, J. A., T. Haug, and C. Lydersen. 2000. Prey preference and niche overlap of ringed seals Phoca hispida and harp seals P. groenlandica in the Barents Sea. Mar. Ecol. Progr. Ser. 194:233–239.

Wenzel, G. 1987. "I Was Once Independent": The southern seal protest and Inuit. Anthropologica 29:195-210.

Weslawski, J. M. 1994. Diet of ringed seals (Phoca hispida) in a fjord of West Svalbard. Arctic 47:109.

Wiig, Ø., A. E. Derocher, and S. E. Belikov. 1999. Ringed seal (Phoca hispida) breeding in the drifting pack ice of the Barents Sea. Mar. Mam. Sci. 15:595–598.

Williams, M. T., C. S. Nations, T. G. Smith, V. D. Moulton, and C. J. Perham. 2006. Ringed seal (Phoca hispida) use of subnivean structures in the Alaskan Beaufort Sea during development of an oil production facility. Aquatic Mamm. 32(3): 311–324.

Williamson, T. 1997. From Sina to Sikujaluk: Our Footprint. Mapping Inuit Environmental Knowledge in the Nain District of Northern Labrador. Prepared for the Labrador Inuit Association, Nain, NL. v + 92 pp and pull-out maps.

Wolkers, H., B. Van Bavel, A. E. Derocher, Ø. Wiig, K. M. Kovacs, C. Lydersen, and G. Lindström. 2004. Congener-specific accumulation and food chain transfer of polybrominated diphenyl ethers in two Arctic food chains. Enviro. Sci. Tech. 38:1667–1674.

York, J, Dale, A, Mitchell, J, Nash, T, Snook, J, Felt, L, Dowsley, M and Taylor, M. 2015. Labrador polar bear traditional ecological knowledge final report. Torngat Wildlife Plants and Fisheries Secretariat Series 2015/03: iv + 118 p.

Young, B. G., L. L. Loseto, and S. H. Ferguson. 2010. Diet differences among age classes of Arctic seals: evidence from stable isotope and mercury biomarkers. Polar Biol. 33: 153–162.

Young, B. G., and S. H. Ferguson. 2013a. Seasons of the ringed seal: pelagic open-water hyperphagy, benthic feeding over winter and spring fasting during molt. Wildl. Res. 40:52–60.

Young, B. G., and S. H. Ferguson. 2013b Using stable isotopes to understand changes in ringed seal foraging ecology as a response to a warming environment. Mar. Mam. Sci.. 30: 706–725.

Young, B. G., S. H. Ferguson, and N. J. Lunn. 2015. Variation in Ringed Seal Density and Abundance in Western Hudson Bay Estimated from Aerial Surveys, 1995 to 2013. Arctic 3:301–309.

Yurkowski, D. J., M. Chambellant, and S. H. Ferguson. 2011. Bacular and testicular growth and allometry in the ringed seal (Pusa hispida): evidence of polygyny? J. Mamm. 92:803–810.

Yurkowski, D. J., S. Ferguson, E. S. Choy, L. L. Loseto, T. M. Brown, D. C. Muir, C. A. Semeniuk et al. 2016b. Latitudinal variation in ecological opportunity and intraspecific competition indicates differences in niche variability and diet specialization of Arctic marine predators. Ecol. Evol. 6:1666–1678.

Yurkowski, D. J., S. H. Ferguson, C. A. Semeniuk, T. M. Brown, D. C. Muir, and A. T. Fisk. 2016c. Spatial and temporal variation of an ice-adapted predator’s feeding ecology in a changing Arctic marine ecosystem. Oecologia 180(3):631–644.

Yurkowski, D. J., C. A. Semeniuk, L. A. Harwood, A. Rosing-Asvid, R. Dietz, T. M. Brown, S. Clackett et al. 2016a. Influence of sea ice phenology on the movement ecology of ringed seals across their latitudinal range. Mar. Ecol. Progr. Ser. 562:237–250.

Zhu, J., R. J. Norstrom, D. C. G. Muir, L. A. Ferron, J.-P. Weber, and E. Dewailly. 1995. Persistent chlorinated cyclodiene compounds in ringed seal, polar bear, and human plasma from Northern Québec, Canada: identification and concentrations of photoheptachlor. Environ. Sci. Tech. 29:267–271.

Biographical summary of report writer(s)

Jeff W. Higdon is a consulting biologist based in Winnipeg, MB. His PhD is from the University of Manitoba, where he carried out research on the biogeography of world pinnipeds and the influence of evolutionary adaptations to sea ice on the distribution patterns of polar species. Since 2005, he has conducted extensive field research on Arctic marine mammals. Other research projects have involved collecting and interpreting Aboriginal Traditional Knowledge, historical research on marine mammal hunting, spatial analysis of animal movements and habitat selection, and assessments of potential environmental impacts to marine biota from proposed development projects and Arctic shipping. Current research activities include developing Arctic monitoring programs, conducting risk assessments, reviewing industrial development projects, and preparing wildlife species status updates. Jeff has worked for government, Inuit, and conservation organizations and written over 40 peer-reviewed scientific papers, book chapters and technical reports.

Stephen D. Petersen (MSc, PhD, Assiniboine Park Zoo, Winnipeg, MB) is the Head of Conservation and Research for Assiniboine Park Zoo. The Conservation and Research Department runs active field and zoo-based programs from the labs and offices at the Leatherdale International Polar Bear Conservation Centre. Recent research projects at the LIPBCC have focused on the ecology and genetics of Arctic mammals (Polar Bear and seals) as well as engaging citizen scientists to help monitor Arctic species like beluga whales. Stephen has a PhD from Trent University (Ontario), MSc from Acadia University (Nova Scotia) and BSc from the University of Alberta (Alberta). Stephen is also Adjunct Professor at both University of Winnipeg and University of Manitoba, a past-president of the Manitoba chapter of The Wildlife Society, and serves on the Terrestrial Mammal Sub-Committee of COSEWIC (the Committee on the Status of Endangered Wildlife in Canada).

Meagan Hainstock (MSc, Polar Bears International, Winnipeg, MB) is the Senior Director for Canada with Polar Bears International. She has worked on a variety of research projects relating to marine mammals in Canada and abroad, including studies of Ringed Seal and Beluga in Canada, and she specializes in science communications for a variety of audiences.

Collections examined

No collections were examined.

Appendix 1. COSEWIC Threats assessment for Ringed Seal, Pusa hispida.

Species or Ecosystem Scientific Name:
Ringed Seal, Pusa hispida

Date:
27/06/2018

Assessor(s):
Draft completed by report authors (27 June 2018), telecon 3 Aug 2018: Jeff Higdon, Stephen Petersen, David Lee, Hal Whitehead, Dwayne Lepitzki, Karen Timm, Tom Jung, Kyle Ritchie, Mark Basterfield, Mike Hammill, Marie-Auger Methe, Jim Goudie, Aqqalu Rosing-Asvid, Dave Yurkowski, Chanda Turner, Emily Way Nee, Paul Irngaut, Bert Dean, Colin Webb, Michael Ferguson, Christine Abraham, Kate Davis

References:
draft calculator and provision (6-month draft) COSEWIC status report

Overall Threat Impact Calculation
Threat Impact Level 1 Threat Impact Counts high range Level 1 Threat Impact Counts low range

A (Very High)

0

0

B (High)

1

0

C (Medium)

0

0

D (Low)

0

1

Calculated Overall Threat Impact:

High

Low

Assigned Overall Threat Impact:
BD = High - Low

Overall Threat Comments
Generation Time = 13 years (3 generations = 39 years); EOO=4,403,651 km2.

Threat assessment worksheet table
Number Threat Threat impact Impact (calculated) Scope (next 10 Yrs) Severity (10 Yrs or 3 Gen.) Timing Comments

1.2

Commercial & industrial areas

Not applicable Not applicable Not applicable Not applicable Not applicable

!Potential for military base to be developed in northern waters (e.g., Resolute Bay). Ship port development at some sites in progress (deep sea port, small craft harbour- Iqaluit, small craft harbour - Pond Inlet).

1.3

Tourism & recreation areas

Not applicable Not applicable Not applicable Not applicable Not applicable

"Tourism and recreation sites with a substantial footprint" - there aren't any substantial areas on sea ice or water with a substantial footprint. Increasing cruise ship and private craft use of the Arctic (see shipping and recreational activities) Pond Inlet is in the process of building a small craft harbour; other communities showing interest in this type of development as well. These sites could be used for tourists in the next decade. Extent of direct overlap with seal habitat is unknown but small proportions of population could be displaced.

2.4

Marine & freshwater aquaculture

Not applicable Not applicable Not applicable Not applicable Not applicable

No aquaculture in species range at present and none proposed to our knowledge, but possibility for development exists.

3

Energy production & mining

Not applicable

Negligible

Small (1-10%)

Negligible (<1%)

High - Low

Undersea mineral exploration and potential future oil/gas activities potential threat. The nature and frequency of exploration will increase and potentially impact more seals each year.

3.1

Oil & gas drilling

Not applicable

Negligible

Small (1-10%)

Negligible (<1%)

High - Low

Presently some oil and gas development in Alaska (Southern Beaufort), and a small number of Canadian seals are exposed to this outside of Canada's boundaries. In Greenland, the Government has published an oil and mineral strategy (2014-2018) that attempts to maintain the current levels of exploration activity in the hope that they will result in a commercially viable oil discovery. In 2017 and 2018, the Government intends to to focus its licensing activities in Baffin Bay and Davis Strait which shares seals with Canada. The Nunavut Impact Review Board is currently coordinating an Strategic Environmental Assessment in Baffin Bay and Davis Strait (SEA). The purpose of SEA is to understand the possible types of offshore oil and gas related activities that could be proposed in the Canadian offshore waters of Baffin Bay and Davis Strait. In 2016, the federal government announced that Canadian drilling in the Arctic will be reviewed every 5 years after an initial moratorium on offshore oil and gas activity in the Arctic. In the Yukon, a small part of Canadian population would be affected at the borders with Alaska and Greenland where oil and gas is present, and some animals would be exposed at a very local level. Industry interest in oil and gas exploration and development in the Beaufort Sea has increased since 2007. The resource potential of the Beaufort Sea is estimated at 67 trillion cubic feet of natural gas and 7 billion barrels of oil in the Mackenzie Delta/Beaufort Sea basin. Literature suggests displacement may occur but may not be permanent. It is uncertain but probably neglible if there would be population level impact.

3.2

Mining & quarrying

Not applicable Not applicable Not applicable Not applicable Not applicable

Mining itself is not a threat but shipping of products may be. There are active mines in Nunavut, Nunavik and Nunatsiavut, with other mines proposed or in development.

4

Transportation & service corridors

Not applicable

Negligible

Pervasive (71-100%)

Negligible (<1%)

High (Continuing)

Not applicable

4.1

Roads & railroads

Not applicable

Negligible

Negligible (<1%)

Negligible (<1%)

High (Continuing)

Railway transporation of iron ore has been approved (southern shipping route) - proposed (northern shipping route) for the Mary River Iron Mine (Baffinland) but potential impacts to Ringed Seal are unknown. Some ice road use off of Alaska where some dens can be impacted by ice road building. Changes in sea ice are expected to occur further south, and changes in ice road construction including frequency and placement may reduce impact such as fewer ice roads being utilized. However, ice road construction further north may increase if mine exploration increases.

4.2

Utility & service lines

Not applicable Not applicable Not applicable Not applicable Not applicable

Proposal for Quintillion Expressnet telecommunications line across Arctic to connect to Europe to Nunavut. Proposed line goes along mainland Canada (has been laid in Alaska but not yet in Canada). Secondary line when funded, would go up east Baffin Coast to connect northern communities. Marine footprint impacts involve laying cable out from slow moving ship, and may not affect seals when cable on sea floor.

4.3

Shipping lanes

Not applicable

Negligible

Pervasive (71-100%)

Negligible (<1%)

High (Continuing)

Most communities are serviced by shipping (bulk sealifts and fuel resupply), which may increase with development. Mines are also supplied by shipping, and ore may be shipped out for processing (e.g., Mary River). The potential also exists for local impacts of icebreaking through pupping habitat. At present there is limited icebreaking (mainly Community Government Service support for community resupply, some shipping of ore from mines in Nunavik (Hudson Strait) and Nunatsiavut), but it could increase in the future. Baffinland has proposed icebreaking to service the Mary River Iron Mine but these plans were suspended but could be brought forward again. Includes ship strikes (i.e., damage to birth lairs, pup mortality), displacement, increased stress levels due to disturbance.

4.4

Flight paths

Not applicable Not applicable Not applicable Not applicable Not applicable

Aircraft fly over Ringed Seal habitat throughout much of the Canadian range, but impacts are likely to be negligible because of altitude of aircraft.

5

Biological resource use

Not applicable

Negligible

Pervasive (71-100%)

Negligible (<1%)

High (Continuing)

Not applicable

5.4

Fishing & harvesting aquatic resources

Not applicable

Negligible

Pervasive (71-100%)

Negligible (<1%)

High (Continuing)

Ringed Seal is harvested throughout the range. The harvest is largely unquantified. Harvest levels are lower than during the dog sled era. Recently, there are indications from Nunavut, that the harvest is decreasing but there is uncertainty if this reflects declining abundance, effort, or participation in the pelt purchase program used as one measure to monitor harvest. Commercial fishing may impact the Ringed Seal population but current data from Alaska suggest that the by-catch is low (3.9 seals/year). There are areas where no harvesting occurs, but given potential for long distance movements and migration, these individuals may be exposed.

6

Human intrusions & disturbance

Not applicable

Negligible

Pervasive (71-100%)

Negligible (<1%)

High (Continuing)

Not applicable

6.1

Recreational activities

Not applicable

Negligible

Pervasive (71-100%)

Negligible (<1%)

High (Continuing)

Some on-ice (i.e., floe edge) arctic tourism but impacts minimal. Biggest impacts to seals likely via cruise ships and private yachts - see shipping above. Strikes, displacement, increased stress from disturbance likely. In next decade with decline in sea ice, more sites may become increasingly accessible than in the past for tourism, which may increase the scope.

6.2

War, civil unrest & military exercises

Not applicable

Negligible

Unknown

Negligible (<1%)

High (Continuing)

The Department of National Defence executes 2-4 Annual Sovereignty Operations (Nunavlivut, Nunakput, Nanook). Navy refueling station project proposed for Nanasivik, Nunavut. Ranger patrols occur in every community, including taking military on sea ice for exercises. Military patrols may occur within the next 10 years with acquisition of ice capable Arctic/Offshore Patrol Vessels.

6.3

Work & other activities

Not applicable

Negligible

Pervasive (71-100%)

Negligible (<1%)

High (Continuing)

Undersea mineral exploration and potential future oil/gas activities potential threat. The nature and frequency of exploration will increase and impact more seals each year. (scored under 3.1 and 3.2). Considers all community activities on ice.

7

Natural system modifications

Not applicable

Negligible

Small (1-10%)

Negligible (<1%)

High (Continuing)

Not applicable

7.2

Dams & water management/use

Not applicable

Unknown

Small (1-10%)

Unknown

High (Continuing)

A consideration in the Hudson Bay system, where changes are occuring due to freshwater inputs from hydroelectric dams. Hydroelectric developments in Hudson Bay are influencing the hydrologic cycle, impacts to seals unknown. Similar development proposed near Iqualuit but there has been no activity to date.

7.3

Other ecosystem modifications

Not applicable

Negligible

Small (1-10%)

Negligible (<1%)

High (Continuing)

If Killer Whale (top predator) range extension leads to increase in Ringed Seal predation, this could present an ecosystem modification and a population level effect. Some impacts of Killer Whales on seal prey were discussed but impacts unknown (but likely negative). Other seal populations may be increasing in abundance and or use of the Arctic (Harbour Seals and Harp Seals) and could present increased competition for prey.

Hydroelectric developments in Hudson Bay are influencing the hydrologic cycle and the impacts to seals remain unknown. Communities in Hudson Bay have stated that these developments have impacted wildlife (Voices from the Bay: Traditional Ecological Knowledge of Inuit and Cree in the Hudson Bay Bioregion). Hydroelectric development has been proposed near Iqlauit (Nunavut) but there has been no activity to date. Tidal developments are not occuring at present.

8

Invasive & other problematic species & genes

Not applicable

Unknown

Pervasive (71-100%)

Unknown

High (Continuing)

Not applicable

8.1

Invasive non-native/alien species/diseases

Not applicable Not applicable Not applicable Not applicable Not applicable

Increased shipping increases potential of invasive species introductions via ballast water or hull fouling. Some invasive species are moving north and may already be in Ringed Seal range in Labrador, with unknown impacts.

8.2

Problematic native species/diseases

Not applicable

Unknown

Pervasive (71-100%)

Unknown

High (Continuing)

Disease expansion - brucellosis and other unicellular parasites, little data, but increasing throughout Arctic, especially with new vectors. However, causes are unknown. Distemper and other viruses expanding as well.

8.4

Problematic species/diseases of unknown origin

Not applicable

Unknown

Unknown

Unknown

Unknown

Not applicable

8.5

Viral/prion-induced diseases

Not applicable

Unknown

Unknown

Unknown

Unknown

Not applicable

8.6

Diseases of unknown cause

Not applicable

Unknown

Unknown

Unknown

Unknown

Cases of hair loss reported in the southern Beaufort Sea and Nunavik; however causes are unknown.

9

Pollution

Not applicable

Unknown

Pervasive (71-100%)

Unknown

High (Continuing)

Not applicable

9.1

Domestic & urban waste water

Not applicable

Negligible

Negligible (<1%)

Unknown

High (Continuing)

In wastewater there are potential local sources for contamination (including persistent pollutants) - little information available at present. Sediments from ice roads discussed. Waste systems discussed.

9.2

Industrial & military effluents

Not applicable

Unknown

Small (1-10%)

Unknown

High (Continuing)

Potential for spills, leakage from tanks considered here. It was noted that there are naturally occuring oil seeps along the coast of Baffin Island.

9.3

Agricultural & forestry effluents

Not applicable Not applicable Not applicable Not applicable Not applicable

Little to no agriculture or forestry activties adjacent to Ringed Seal habitat.

9.4

Garbage & solid waste

Not applicable

Unknown

Pervasive (71-100%)

Unknown

High (Continuing)

Garbage dumps in communities throughout Ringed Seal range but limited/no effect on seals. Garbage (household waste and from cruise ships) dumped in water (can cause entanglement) or on sea ice could have an effect, as could plastic pollution which is pervasive in marine environments. Microplastics were discussed but impacts on seals unknown. Impacts of newer contaminants discussed and are yet unknown.

9.5

Air-borne pollutants

Not applicable

Unknown

Pervasive (71-100%)

Unknown

High (Continuing)

Long range transport of pollutants through air when chemicals volatilize, movement through water as well. PCBs and radioactive material can have a wide regional impact, especially in marine systems. Atmospheric transport of pollutants and pesticides was considered. Mercury was also discussed. Routine burning at community dump sites is another source of air-borne pollutants. Impacts of newer contaminants discussed and are yet unknown.

9.6

Excess energy

Not applicable

Unknown

Pervasive (71-100%)

Unknown

High (Continuing)

Population level impacts from acoustic noise in the open water season as shipping from resupply and tourist activity increases is unknown. The US military has agreed not to use military grade sonar in exercises. Again, impacts to Canadian population unknown.

10.2

Earthquakes/

tsunamis

Not applicable Not applicable Not applicable Not applicable Not applicable

Earthquakes have been recorded in Baffin Bay but their impacts on Ringed Seal are unknown.

10.3

Avalanches/

landslides

Not applicable Not applicable Not applicable Not applicable Not applicable

Avalanches or landslides could impact coastal habitat but impacts likely to be minor.

11

Climate change & severe weather

BD

High - Low

Pervasive (71-100%)

Serious - Slight (1-70%)

High (Continuing)

Not applicable

11.1

Habitat shifting & alteration

BD

High - Low

Pervasive (71-100%)

Serious - Slight (1-70%)

High (Continuing)

Sea ice habitat and snow are crucial for Ringed Seal (maternity denning, basking/moulting habitat), and declines in ice extent and quality are the biggest threat to persistence. Changes to habitat and associated responses by seals will vary in both space and time, with possibility that some areas may have improved conditions (such as areas that have been covered by thick multi-year ice in the past and now tend to be covered with annual ice). Sea ice presence is also a critical factor in the Arctic marine food web and changes could have pronounced ecosystem-level effects. Projections on population impacts from Baltic sea ice loss on pupping was discussed. Range in severity was used to reflect uncertainty.

11.2

Droughts

Not applicable Not applicable Not applicable Not applicable Not applicable

Droughts do not pose a threat.

11.3

Temperature extremes

Not applicable

Unknown

Small (1-10%)

Unknown

High (Continuing)

Temperature extremes can affect maternity dens and cause them to collapse, which exposes pups to weather and predators. Such events are usually local in scale and likely would not cause a population level impact. In the past early rain events have had impacts on den collapse, and rain on ice and snow events are predicted to increase. Aerial surveys in some sites are being run earlier than historically (potentially suggesting a shift in life history events or a logistical necessity to detect seals efficiently).

11.4

Storms & flooding

Not applicable

Unknown

Unknown

Unknown

High (Continuing)

Increasing storm events can lead to effects on ice development (e.g., causing ice to break up), but such storms also make harvesting more difficult and could lead to reduced human-caused mortality. Impacts are not well understood and are therefore scored as unknown.

Classification of Threats adopted from IUCN-CMP, Salafsky et al. (2008).

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