Habitat matters for Canadian wildlife species
Thirty-five Canadian wildlife species, from whales to mosses, were assessed as at risk at the recent COSEWIC (Committee on the Status of Endangered Wildlife in Canada) meeting in Kananaskis, Alberta, April 29-May 4, 2012. Once again, habitat loss emerged as the most common threat to Canadian wildlife, underscoring that all species, not just our own, need a healthy home in order to thrive.
Fishes face increasing pressure from declining habitat
Habitat loss and degradation are the most common cause of species decline worldwide and Canada’s freshwater fishes are no exception. It’s not just freshwater fishes that rely on streams and rivers; a very large fraction of Canadian biodiversity including birds, insects, plants and amphibians rely on healthy aquatic habitats. Seven freshwater fishes were assessed by COSEWIC as being at risk in Canada. These include the Northern Madtom, Blackstripe Topminnow, Pugnose Minnow and Silver Chub, all of which are found in southwestern Ontario. In this region, the Sydenham River alone is home to a number of additional species previously assessed as at risk by COSEWIC. These include three additional freshwater fishes, five mussels and the Spiny Softshell. In every case, loss or degradation of habitat was key to these designations. While some aspects of water quality in the Sydenham River have improved as a result of environmental regulation that limits industrial pollution of the river, the habitat of these non-commercial fishes and other species remains threatened by agricultural inputs and urbanization. The unique biodiversity of this region will only improve with careful monitoring and rigorous protection of fish habitat.
Canadian icon faces an uncertain future
Few species can match the Grizzly Bear as an emblem of Canadian wilderness. While grizzlies are at least twice as strong as the average human, in reality they are likely to pay with their lives when our two species interact. Over the past century, human-caused mortality and declining habitat have reduced the Grizzly Bear’s global range by more than 50%. Today, Canada has a major responsibility for safeguarding remaining grizzly populations. In the southern part of their range, where they are in regular contact with humans, many populations are declining. In the north, the impacts of ongoing and escalating extraction of natural resources are a cause for concern. Considering these threats, the Grizzly Bear was assessed as Special Concern by COSEWIC. This assessment concludes a two-year process incorporating science and Aboriginal Traditional Knowledge.
Enigmatic American Eel swims against the current
American Eels are remarkable fish. They spend most of their lives in freshwater then return to the sea, migrating from streams and rivers that span Greenland to South America to spawn in the mid-Atlantic Sargasso Sea. Young eels journey over 7000 km to rivers and streams where they live for up to 20 years before starting their downstream migration to the sea. This complex lifestyle exposes the eels to a variety of threats over large areas and timespans, which resulted in a Threatened designation. American Eels that migrate to Lake Ontario and the upper St. Lawrence River have declined drastically over the past 40 years. Despite improvements to hydroelectric dams that reduce risks to young eels migrating upstream, older eels still suffer high mortality during the downstream migration. In Atlantic Canada, existing fisheries place additional pressure on the American Eel.
Canada’s other beaver can’t handle the heat
While nearly all Canadians can recognize the North American Beaver, its distant relative, the Mountain Beaver is probably unknown to most. Mountain Beavers occur in Canada only in the Coast Mountains and south of the Fraser River in British Columbia. Mountain Beaver, the last living representative of an ancient lineage of rodents, was assessed as Special Concern. These beavers live in underground dens built in deep, loose soil along the edges of cool, forested streams. These sites can be degraded by forestry practices that compact the soil. Mountain Beavers are highly intolerant of heat and drought, and are especially sensitive to climate change. The Magnum Mantleslug, another wildlife species assessed as Special Concern, is similarly restricted to edges of cool streams and seepages and also faces threats from logging and climate change.
No avoiding human impacts
Northern and ocean-dwelling species should be buffered from human activity because more than two-thirds of all Canadians live within 200 km of our southern border; this is not true for many Canadian wildlife species. As with the grizzly, whose movements are increasingly disrupted by human encroachments into boreal and arctic regions, other northern and marine species live under the specter of human activities. For the Buff-breasted Sandpiper, a shorebird assessed as Special Concern, increased resource exploration on their Canadian Arctic nesting grounds poses a threat. The Marbled Murrelet, assessed as Threatened, is a charismatic diving bird that occurs in Canada along the BC coast where it is vulnerable to the loss of ancient forests where it nests. In the marine environment where murrelets feed, proposed increases in shipping traffic pose an additional threat. On the Atlantic coast, Leatherback Sea Turtles encounter fishing gear while feeding in Canadian waters. Entanglement with fishing lines and ropes attached to traps pose a key threat to this wildlife species, assessed as Endangered by COSEWIC. These species demonstrate how Canadian wildlife depends critically on habitat protection.
COSEWIC’s next scheduled wildlife species assessment meeting will be held in Ottawa, ON, in November 2012.
COSEWIC assesses the status of wild species, subspecies, varieties, or other important units of biological diversity, considered to be at risk in Canada. To do so, COSEWIC uses scientific, Aboriginal traditional and community knowledge provided by experts from governments, academia and other organizations. Summaries of assessments are currently available to the public on the COSEWIC website (www.cosewic.gc.ca) and will be submitted to the Federal Minister of the Environment in late summer 2012 for listing consideration under the Species at Risk Act (SARA). At that time, the full status reports and status appraisal summaries will be publicly available on the Species at Risk Public Registry (www.sararegistry.gc.ca).
There are now 650 wildlife species in various COSEWIC risk categories, including 287 Endangered, 161, Threatened, 179 Special Concern, and 23 Extirpated (i.e. no longer found in the wild in Canada). In addition to these wildlife species that are in COSEWIC risk categories, there are 15 wildlife species that are Extinct.
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 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 Status 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.
Further details on all wildlife species assessed, and the reasons for designations, can be found on the COSEWIC website at: www.cosewic.gc.ca