Ogden's Pondweed (Potamogeton ogdenii) COSEWIC assessment and status report: chapter 2

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COSEWIC Executive Summary

Species information

Ogden’s pondweed (Potamogeton ogdenii) is a submerged, annual aquatic plant with freely branching, compressed and thread-like, rigid stems. The long narrow leaves are greenish-brown. Potamogeton ogdenii is similar to other narrow-leaved members of the genus, such as P. confervoides, P. zosteriformis, P. hillii, P. foliosus, P. friesii, P. strictifolius, P. obtusifolius, and P. pusillus. Ogden’s pondweed was described in 1983 as a new species.

Distribution

Ogden’s pondweed occurs in southern Ontario, western Connecticut, central New York, central Vermont, and western Massachusetts. In Canada it has an extent of occurrence of 1000 km², if the historic locality is assumed to occur roughly in the centre of Hastings Co.

Habitat

This species is found in slow-moving streams, beaver ponds, and lakes with clear, alkaline water. The two recent Ontario sites are associated with marble bedrock.

Biology

Ogden’s pondweed reproduces mainly vegetatively by the production of winter buds called turions. Seeds are uncommonly produced. Like other narrow-leaved pondweeds, Ogden’s pondweed probably provides habitat for aquatic invertebrates, food for mammals and waterfowl, and cover for amphibians and fish.

Population sizes and trends

The only Canadian occurrences of Ogden’s pondweed are in eastern Ontario where it is known from Hastings County (1873), Murphys Point Provincial Park (1974), and Davis Lock on the Rideau Canal (1987). None of these sites were confirmed in 2005 or 2006 but suitable habitat exists in the vicinity of the two more recently documented sites. The species is likely still present in Canada.

Limiting factors and threats

Potential threats to Ogden’s pondweed are habitat destruction, competition from invasive plants, and low population numbers.

Special significance of the species

As is the case with other pondweeds, Ogden’s pondweed may be eaten by waterfowl and mammals, and provides cover for aquatic invertebrates and fish. No traditional or Aboriginal uses of Ogden’s pondweed have been documented.

Existing protection

Ogden’s pondweed is considered critically imperiled globally and is designated as Endangered in Massachusetts and New York. The species has no formal status in Canada.

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

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)^Footnote1

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)^Footnote2

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

Data Deficient (DD)^Footnote3

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.