COSEWIC Assessment and Status Report on the Yellowmouth Rockfish Sebastes reedi in Canada

Table of Contents

Document Information

List of Figures

Figure 1. Adult Yellowmouth Rockfish
Figure 2. Line drawing of adult Yellowmouth Rockfish
Figure 3. Mean CPUE (kg/h) of Yellowmouth Rockfish caught by the trawl fishery in 0.10 × 0.0750 grid cells along the BC coast. Isobaths displayed are 200 m and 1000 m
Figure 4. Depth frequency of tows that captured Yellowmouth Rockfish from commercial trawl logs (1996–2007)
Figure 5. Potential Yellowmouth Rockfish habitat along the BC coast
Figure 6. Relative frequency of maturity stages of Yellowmouth Rockfish, expressed by month
Figure 7. Maturity ogives for Yellowmouth Rockfish using ages grouped at 2–year intervals. The age of each group is expressed as the mean of the observed ages in each group
Figure 8. Locations of all trawls from the G.B. Reed trawl survey (1967–1984) which caught Yellowmouth Rockfish
Figure 9. Locations of tows conducted by the Queen Charlotte Sound shrimp survey from 1999 to 2007. The tows to the east of Calvert Island represent Stratum 111 which was not used in the analysis (from Haigh and Starr 2008). Tows to the south of Calvert Island are in stratum 110, and the remaining tows west of the coastal islands are in stratum 109
Figure 10. Tow locations in the Vancouver INPFC region for each of the seven triennial surveys that included Canadian waters
Figure 11. Catch history of Yellowmouth Rockfish by US and Canadian fleets along the BC coast
Figure 12. Relative index for Yellowmouth Rockfish in Queen Charlotte Sound from the QCS synoptic bottom trawl survey
Figure 13. Relative index for Yellowmouth Rockfish on the west coast of Vancouver Island from the WCVI synoptic bottom trawl survey
Figure 14. Relative biomass estimates for Yellowmouth Rockfish from the Goose Island Gully G.B. Reed trawl surveys from 1967–1984, with bias corrected 95% confidence intervals from 1000 replicates
Figure 15. Relative biomass estimates for Yellowmouth Rockfish from the QC Sound shrimp trawl survey for 1999–2007, with bias corrected 95% confidence intervals from 1000 bootstrap replicates
Figure 16. Locations of all trawls from the Queen Charlotte Sound shrimp trawl survey (1999–2007) which caught Yellowmouth Rockfish
Figure 17. Relative biomass estimates for Yellowmouth Rockfish from NMFS triennial surveys in the INPFC Vancouver region (total region, Canadian portion, and US portion) with 95% bias corrected error bars estimated from 5000 bootstrap replicates
Figure 18. Time series on research survey indices (ln scale) of Yellowmouth Rockfish adjusted for their respective intercepts in a combined analysis of covariance
Figure 19. Annual index trend in Yellowmouth Rockfish commercial trawl CPUE data (1996–2006) based on a general linear model (GLM) analysis with five factors: year, month, depth, latitude, and vessel
Figure 20. Annual index trend and factor coefficients for the GLM analysis of Yellowmouth Rockfish commercial trawl CPUE data (April 1996 to March 2007)
Figure 21. Relative frequency of Yellowmouth Rockfish lengths by calendar year (1966–1982) and trip type
Figure 22. Relative frequency of Yellowmouth Rockfish lengths by calendar year (1983–1995) and trip type
Figure 23. Relative frequency of Yellowmouth Rockfish lengths by calendar year (1996–2007) and trip type

List of Tables

List of Appendices

Yellowmouth Rockfish

THREATENED – 2010

COSEWIC - Committee on the Status of Endangered Wildlife in Canada

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. 2010. COSEWIC assessment and status report on the Yellowmouth Rockfish Sebastes reedi in Canada. Committee on the Status of Endangered Wildlife in Canada. Ottawa. vii + 57 pp.

Production note:
COSEWIC would like to acknowledge Andrea L. Smith for writing the status report on the Yellowmouth Rockfish Sebastes reedi in Canada, prepared under contract with Environment Canada. This report was overseen and edited by Alan Sinclair, Co–Chair of the COSEWIC Marine Fishes Specialist Subcommittee, and Howard Powles, previous Co–Chair of the COSEWIC Marine Fishes Specialist Subcommittee.

For additional copies contact:

COSEWIC Secretariat
c/o Canadian Wildlife Service
Environment Canada
Ottawa, ON
K1A 0H3

Tel.: 819–953–3215
Fax: 819–994–3684
E–mail
Website

Également disponible en français sous le titre Évaluation et Rapport de situation du COSEPAC sur le sébaste à bouche jaune (Sebastes reedi) au Canada.

Cover illustration/photo:
Yellowmouth Rockfish — Line drawing of adult Yellowmouth Rockfish. Illustrator is Wayne Laroche. Taken from Matarese et al. 1989.

© Her Majesty the Queen in Right of Canada, 2010.
Catalogue CW69–14/605–2010E–PDF
ISBN 978–1–100–15991–1

Common name
Yellowmouth Rockfish

Scientific name
Sebastes reedi

Status
Threatened

Reason for designation
As with other rockfish species, this slow–growing (generation time 30 years), long–lived (maximum age 100 years) species is vulnerable to commercial fishing. Research vessel surveys indicate that abundance has declined considerably over the past 40 years (1.5 generations). While contemporary surveys designed specifically for groundfish species indicate a recent period (5 years) of relative stability, it is not clear that the decline has ceased. The initial period of decline occurred as the commercial fishery for this and other rockfish species developed. Although this is considered normal for a newly exploited population, the total decline in abundance is inferred to be well beyond what is optimal for an exploited population. The absence of any strong recruitment events during the last 20 years is also a concern. The species is an important component of BC’s commercial fisheries. Fishing continues to be a threat and there is no established limit reference point to help manage these fisheries in a precautionary manner.

Occurrence
Pacific Ocean

Status history
Designated Threatened in April 2010.

Species information

The Yellowmouth Rockfish is one of more than 35 rockfish species occurring in marine waters along the British Columbian coast, and one of more than 60 found along the entire Pacific coast of North America. It is similar to the Pacific Ocean Perch, and, prior to the mid–1970s, both species were classified as “red rockfish” or “ocean perch”. Other common names for the Yellowmouth Rockfish include “reedi”, “red eye”, “red snapper” and “rockcod”. The species is distinguished from other rockfish by characteristic yellow, red and black markings in its mouth. Adults are primarily red, with black mottling on their backs. No population genetic studies of Yellowmouth Rockfish have been conducted and this report considers all individuals within BC as part of a single population.

Distribution

The range of Yellowmouth Rockfish extends from the northern Gulf of Alaska to northern California. The species is most abundant between southeastern Alaska and Oregon. Yellowmouth Rockfish are found on the continental slope throughout British Columbia and are caught in high densities in Queen Charlotte Sound, off northwest Vancouver Island and offshore from Rennell Sound. The area of occupancy of Yellowmouth Rockfish in Canadian waters is estimated to be 11 000–34 000 km².

Habitat

Yellowmouth Rockfish occur at depths of 100–430 m along the continental slope. Information is lacking on larval and juvenile stages, but like other rockfish, immature Yellowmouth are pelagic. Adults frequently aggregate over rocky substrate. In British Columbia Yellowmouth are most frequently captured by the trawl fishery between 130–357 m. Based on the species’ apparent depth and substrate preferences, approximately 48 000 km² of potential habitat is estimated to exist for Yellowmouth Rockfish in Canada, which can be used as a proxy for the extent of occurrence of the species.

The continental slope habitat associated with Yellowmouth Rockfish is subject to fishing activity in BC, most notably commercial bottom trawling. Very little of this offshore area receives habitat protection. Yellowmouth Rockfish associate with several other groundfish species in mid–water assemblages, including Pacific Ocean Perch, Arrowtooth Flounder and Redstripe Rockfish.

Biology

Limited research has been conducted on the Yellowmouth Rockfish. In British Columbia fertilization takes place in February and females give birth to live young from April through June. Immature Yellowmouth are pelagic for up to a year, during which time the larvae metamorphose into juveniles and finally settle on the ocean floor. Inter–annual recruitment is typically highly variable in rockfish species. The last known strong recruitment year for Yellowmouth Rockfish in Canada was in 1982.

Individuals mature at approximately 10 years of age, when females average lengths of 39 cm and males 37 cm. The maximum length recorded for the species is 60 cm. Otolith measurements suggest that individuals live a maximum of 99 years in British Columbia. The average age of fish caught between 1978–1993 was 22 years old. The generation time (average age of parents in the population) is 30 years. Like other rockfish, Yellowmouth have closed swim bladders which make them vulnerable to injury when captured from deep water. Juvenile rockfish may be preyed upon by other fish, such as hake and salmon, as well as seabirds.

Population sizes and trends

Most Yellowmouth Rockfish are captured by the trawl fishery, which has been active since the 1930s. Information on species composition and discarding were not routinely recorded prior to the mid–1970s, which adds uncertainty to historical catch estimates. The total coastwide catch by both domestic and foreign vessels over the lifetime of the fishery is estimated to be at least 60 000 t (41 million fish). Catch by Canadian vessels peaked in 1986 at 2491 t and averaged 1842 t annually between 1997–2007.

Contemporary surveys provide limited information on Yellowmouth abundance patterns because the time–series are too short (less than 5 years in many cases) and the indices are highly variable. Historical surveys dating to 1967 did not provide synoptic spatial coverage of the entire DU, and these survey results were also highly variable for this species. Nonetheless, these historical surveys indicate a substantial decline in Yellowmouth Rockfish abundance between 1967–1999. Catch per unit effort data from 1996–2007 indicate a 2.5% annual decline in the species. This trend may be influenced by changes in fishing behaviour. Furthermore, abundance levels may reflect the low recruitment which has characterized the BC population since the early 1980s.

Information is lacking on the status of neighbouring populations of Yellowmouth in US waters. British Columbia appears to be the population centre for the species, as catch levels are much lower in the US.

Limiting factors and threats

Rockfish life history traits of slow growth, delayed maturity, and longevity potentially make this group of groundfish vulnerable to overfishing, habitat loss from bottom trawling and adverse environmental changes. Recruitment is highly variable and factors controlling this are unknown. Yellowmouth Rockfish typically co–occur with other commercially important groundfish species and are taken as part of a multi–species fishery.

Commercial fishing is the primary threat to Yellowmouth Rockfish. The species is caught mainly by bottom and mid–water trawls in BC. The lack of reliable historical and contemporary records on Yellowmouth abundance poses a challenge for determining the current population status of the species across its range. Additionally, Yellowmouth may be mistakenly identified as Pacific Ocean Perch once captured.

Special significance of the species

Yellowmouth Rockfish is a commercially important species in British Columbia. In the 2007–2008 fishing season, the total Canadian catch of the species had a landed value of approximately $1.5 million.

Existing protection

There is no specific protection for Yellowmouth Rockfish either in Canadian or US waters. The conservation status of the species has not been assessed.

Yellowmouth Rockfish has been managed under a single species quota since 1979, currently set at 2364 t for the 2008–2009 fishing season. In the US, Yellowmouth Rockfish are managed under slope rockfish assemblage quotas. The species likely receives partial protection from rockfish conservation areas and prohibitions on trawling in sections of its US range.

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 (2010)

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)*
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)**
A wildlife species that has been evaluated and found to be not at risk of extinction given the current circumstances.

Data Deficient (DD)***
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.

* Formerly described as “Vulnerable” from 1990 to 1999, or “Rare” prior to 1990.
** Formerly described as “Not In Any Category”, or “No Designation Required.”
*** 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.

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

COSEWIC Status Report on the Yellowmouth Rockfish Sebastes reedi in Canada – 2010.

The Yellowmouth Rockfish, Sebastes reedi, (Westrheim and Tsuyuki 1967) is a member of the order Scorpaeniformes and family Sebastidae. It was originally classified as Sebastodes reedi (Westrheim and Tsuyuki 1967) but reassigned to the genus Sebastes following taxonomic revisions to Pacific rockfish in the 1970s (Bailey et al. 1970). A recent taxonomic study has produced a well–supported phylogeny of the Sebastes genus, indicating that it is monophyletic, and that the Yellowmouth Rockfish is most closely related to the Darkblotched Rockfish (S. crameri; Hyde and Vetter 2007). Yellowmouth Rockfish are morphologically similar to Pacific Ocean Perch (S. alutus) and both species were often identified as “red rockfish” or “ocean perch” in catch records prior to the mid–1970s (DFO 1999a). Other common names for the species include “red snapper”, “redeye”, “reedi” and “rockcod” (Love et al. 2002; Oregon Dept. Fish and Wildlife 2007).

Adult Yellowmouth Rockfish resemble several other rockfish species (e.g., Pacific Ocean Perch, Chilipepper S. goodei, Redstripe Rockfish S. proriger, Sharpchin Rockfish S. zacentrus) but are distinguished by the yellow, red and black blotches in their pinkish white mouth (Westrheim and Tsuyuki 1967). Adults are predominantly red, intermixed with yellow to orange (or mixed with black for individuals < 40 cm), with diffuse olivaceous mottling on their backs (Fig. 1) (Orr et al. 2000). Three indistinct dark bands are present on the head and a pinkish lateral line extends down the body (Kramer and O’Connell 1995). Yellowmouth Rockfish have an elongated lower jaw with a moderately wide symphyseal knob and a moderately indented caudal fin (Hart 1973; Kramer and O’Connell 1995). Individuals have 13 dorsal and three anal spines (Fig. 2) (Kramer and O’Connell 1995).

Figure 1. Adult Yellowmouth Rockfish (Grant et al. 1996).

Figure 2. Line drawing of adult Yellowmouth Rockfish (Matarese et al. 1989).

No known studies have been conducted on the population genetic structure of the Yellowmouth Rockfish. Westrheim and Tsuyuki (1967) carried out electrophoretic analyses of hemoglobin from Yellowmouth Rockfish collected between Oregon and Alaska and identified two variant protein forms. No corresponding morphological or meristic differences were detected.

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COSEWIC Assessment and Status Report on the Yellowmouth Rockfish Sebastes reedi in Canada – 2010

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