A Living Fossil at Risk of Extinction: One Part of Canada's Decline in Biodiversity
GATINEAU, QUEBEC (Nov 28, 2006). One of Canada's largest freshwater fishes, the Lake Sturgeon, is at risk of extinction. This was one of the key findings of the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), which met in Gatineau, Quebec, on November 22-24, 2006.
The Lake Sturgeon, like all sturgeons, is a living fossil and retains the shark-like features of its ancestors of the Devonian Period. It is an enormous, long-lived fish with a maximum size of 185 kg and a recorded maximum age of 154 years. This species was found to be most at risk in the western parts of its range (Alberta to northwestern Ontario) where it was assessed as Endangered, and is considered to be at some level of risk throughout the remainder of its range in Canada. The Lake Sturgeon faces a variety of threats, including over-harvesting and habitat loss from the construction and operation of dams. Dams have been a significant threat to many other fish species assessed as "at risk" by COSEWIC in the past, including American Eel, White Sturgeon, and the Copper Redhorse.
Over 500 Species at Risk
Altogether, 521 species in Canada are now considered "at risk" by COSEWIC.
In addition to the Lake Sturgeon, seven other species were assessed at this meeting. Of these, native populations of the Westslope Cutthroat Trout, a popular freshwater sport fish in Western Canada, were assessed as Special Concern in British Columbia and Threatened in Alberta. The primary threat to these populations is hybridization and competition with introduced trout species, including non-native strains of Cutthroat Trout and Rainbow Trout. Loss and degradation of stream habitat throughout the range of Cutthroat Trout in Canada have also contributed to the decline.
The Misty Lake Sticklebacks, an endemic species pair found only in one small lake on Vancouver Island in British Columbia, are invaluable for the study of evolutionary processes in nature. They were assessed as Endangered due to the potential threat of illegal, accidental or deliberate release of exotic organisms that continue to be spread in freshwater ecosystems on Vancouver Island.
The Sowerby's Beaked Whale was assessed as being of Special Concern. This rarely observed Atlantic deepwater whale may be adversely affected by man-made noise generated by military sonar and seismic testing.
Among the plants, the Nugget Moss was assessed as Endangered. This globally rare moss occurs at only two locations in Canada, where it is found on steep silt banks in the southern interior of British Columbia. These banks are facing increased erosion often associated with development and road building.
COSEWIC also considered a number of aquatic species that were referred back to it through Governor in Council by Fisheries and Oceans Canada (DFO) for further consideration. After evaluating the information provided by DFO, COSEWIC reaffirmed its original assessments for the Arctic population of Atlantic Cod, Bocaccio, Cusk, and the Lake Winnipeg Physa snail.
Some good news…
There was some good news to report.
COSEWIC determined that Scouler's Corydalis, a large and showy perennial plant found only on Vancouver Island, similar in appearance to the cultivated Bleeding Heart, should be reassigned from Threatened to Not at Risk. Recent surveys indicated that the plant is much more abundant than previously thought. In addition, the Province of British Columbia has created eight new wildlife habitat areas specifically to protect this species under its Forest and Range Practices Act, thus further reducing the threats.
The Greenside Darter, a colourful, perch-like fish found in the Great Lakes area of southern Ontario, previously assessed as Special Concern, has since expanded its range into several new streams and was reassessed as Not at Risk.
COSEWIC assesses the national status of wild species, subspecies, varieties, or other important units of biological diversity, that are considered to be at risk in Canada. To do so, COSEWIC uses scientific, Aboriginal traditional and local or community knowledge provided by many experts from governments, academia and other organizations. Assessment summaries are currently available to the public on the COSEWIC website and will be submitted to the Federal Minister of the Environment in August 2007 for listing consideration under the Species at Risk Act (SARA). At that time, the full status reports will be publicly available on the Species at Risk Public Registry.
There are now 521 species in various COSEWIC risk categories, including 212 Endangered, 136 Threatened, 151 Special Concern, and 22 Extirpated Species (i.e. no longer found in the wild in Canada). In addition, 13 are Extinct and 41 are Data Deficient.
COSEWIC comprises members from each provincial and territorial government wildlife agency, four federal entities (Canadian Wildlife Service, Parks Canada Agency, Fisheries and Oceans Canada, 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 and the Aboriginal traditional knowledge subcommittees.
Definition of COSEWIC terms and risk categories:
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 wildlife species' eligibility for assessment or (b) to permit an assessment of the wildlife species' risk of extinction.
|Dr. Jeffrey Hutchings
Department of Biology
1355 Oxford Street
Edsell Castle Circle
Halifax NS B3H 4J1
Telephone (1): 902-494-2687
Telephone (2): 902-494-3515
|For inquiries on Vascular Plants:
Dr. Erich Haber
60 Baywood Dr.
Stittsville ON K2S 2H5
|For inquiries on Marine Mammals:
Dr. Randall Reeves
Okapi Wildlife Associates
27 Chandler Lane
Hudson QC J0P 1H0
Fax: 450-458-7383 (call first)
|For inquiries on Mosses and Lichens:
Dr. René Belland
Devonian Botanic Garden
University of Alberta
Edmonton AB T6G 2E1
Telephone: (780) 987-3054
|For inquiries on Freshwater Fishes:
Dr. Robert Campbell
983 Route 800 E
St. Albert ON K0A 3C0