Last week the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) met to assess the status of wildlife species in Canada believed to be at risk of extinction. COSEWIC is the independent scientific advisory body that assesses the status of species under the federal Species at Risk Act.
COSEWIC summarized the results of the meeting as “From Abalone to Whales: Aquatic Species in Canada Face Risk of Extinction.” Indeed, the message is clear, and quite grim, for two marine species, the American Plaice and the Northern Abalone.
Both species have undergone precipitous declines, with American Plaice suffering declines of 90% in some areas of Canada’s east coast, and Northern Abalone still declining in British Columbia due to poaching. These declines have continued despite a 20 year moratorium on abalone harvesting and a long-standing plaice moratorium in some fishery areas.
The American Plaice is a flatfish, which, as a juvenile looks like a conventional fish, but as it develops into adulthood, its left eye migrates from the left side of its head to the right side, and from that point onward swims on its side.
The Northern Abalone is marine snail with a flat, oval-shaped shell mottled reddish or greenish, with areas of white or blue. It was the first marine invertebrate to be designated at risk by COSEWIC, in 1999.
The assessment meeting also brought some good news for a marine species – the status of Bowhead Whales in Canada’s eastern Arctic has been upgraded to special concern from the previous status of threatened. Hundreds of years of commercial whaling had depleted Bowhead Whale populations but recent decades of conservation have resulted in increased numbers. However, COSEWIC notes, “Although the increased abundance is encouraging, the species faces an uncertain future in a rapidly changing Arctic climate.”
Two Canadian bird species were also assessed as at-risk for the first time, Whip-poor-will and Horned Grebe (below). Whip-poor-wills are found across much of Canada, but, like many other aerial insectivorous bird species, habitat loss and degradation as well as changes to the insect prey base may be affecting their population.
Abundance indices indicate that Whip-poor-wills have declined by more than 30% over the past 10 years (3 generations), leading COSEWIC to assess them as threatened. Horned Grebes found west of Quebec were assessed as special concern. Canada has approximately 92% of the North American breeding range of this species, and long-term and short-term population declines have resulted from threats like degradation of wetland breeding habitat and pressure on their wintering habitats. Horned Grebes found in the Magdalen Islands were assessed as endangered. Their very small population size (average of 15 adult birds) makes them particularly vulnerable.
The Horned Grebe wasn’t the only wetland species assessed as at risk. Northern Leopard Frogs (below), once ubiquitous wetland residents in many parts of Canada, were determined to be endangered in British Columbia (where they are now only found in a single population in the Creston Valley). The western boreal and prairie populations were assessed as special concern. The Maritime Ringlet, a specialist butterfly found only in Canada, and only in 10 coastal salt marshes in New Brunswick and the Gaspé Peninsula, was classified as endangered.
There are now 585 wildlife species in various COSEWIC risk categories, including 244 endangered, 145 threatened, 160 special concern, and 23 extirpated wildlife species. In addition, 13 are extinct and 45 are data deficient.
As always, Nature Canada will keep tabs on these assessments to make sure that the species receive timely listing under the Species at Risk Act, so that they and their habitats are protected.
photo: Elena Kreuzbert (frog), Vladamir Morozov (grebe)