Biodiversity in decline across all of Canada

Twenty-seven Canadian wildlife species were assessed as at risk at the recent meeting of COSEWIC

Twenty-seven Canadian wildlife species were assessed as at risk at the recent meeting of COSEWIC (Committee on the Status of Endangered Wildlife in Canada), held April 27 – May 2, in Halifax, Nova Scotia.

When the Species at Risk Act (SARA) came into force in 2003, COSEWIC was given the responsibility of providing scientific species assessments to the Minister of the Environment to inform government decisions for protection of species at risk under the Act. Five hundred and eighteen of the species assessed as at risk by COSEWIC are now listed under SARA.

Canada’s pollinators at risk

Two bee species were assessed as at risk at this meeting. Some groups of bumble bees are experiencing dramatic declines worldwide that are not well understood. Suspected causes include impacts from pesticides, pathogens, and human-induced climate change. This downturn is bad for the bees and bad for us. Bees pollinate more than 70 per cent of our crops, and without the services that they provide, our food supply is at risk. Western Bumble Bee was widespread in Canada, but it has undergone a mysterious decline. The southern population of Western Bumble Bee has been reduced in some areas, resulting in a Threatened status. While the northern population appears to be in better shape, declines are known in some areas, and our lack of understanding of what drives bee declines is a cause for concern. The Gypsy Cuckoo Bumble Bee, though less abundant, also used to be widespread across Canada. Despite an increased effort to find this species, none have been seen in Canada since 2008, and it was assessed as Endangered. Cuckoo Bumble Bees have an intriguing way of life: a female invades the hive of another bumble bee species and takes over after removing the queen.

Coldwater shark still in hot water

The Porbeagle is one of 28 species of sharks that occur in Canada. This large-bodied species makes extensive migrations from Canadian waters to the mid-Atlantic. Porbeagle sharks are caught in Canadian and international fisheries both for their fins and their meat. Due to overfishing, the abundance of this shark declined greatly in the 1960s, partially recovered in the 1980s and then collapsed again in the 1990s. The number of sharks remains at about 30 per cent of their 1961 level, and the species was once again assessed as Endangered by COSEWIC. Although fishing licenses for this species were suspended in 2013, they are still caught as bycatch in the tuna, swordfish and groundfish fisheries. COSEWIC first assessed the Porbeagle as Endangered in 2004, but it was not listed on the Species at Risk Act because of the economic losses that would result from suspending the fishery. More recently, Canada supported listing the species under CITES, an international agreement that regulates trade of endangered species.

Wolverine population retreating northward

Although most Canadians have never seen one, Wolverines used to be one of the most widely distributed animals in Canada, with a range that blanketed all three territories, all of western Canada, the prairies, Ontario, Quebec, Labrador and New Brunswick. The range of these secretive carnivores shrank considerably in the early 1900s, and they are no longer known from regions highly modified by humans, especially in southern Canada. Although often subject to high levels of hunting and trapping, this elusive carnivore receives little attention and monitoring. As a result, we have a poor understanding of how populations are faring under climate and land use change. COSEWIC assessed the Canadian population of Wolverine as Special Concern due to increasing industrial activity and greater access to its remote habitats because of new roads and increasingly sophisticated snowmobiles.

Mountain caribou increasingly imperiled

The iconic Caribou, like the Wolverine is known from most parts of Canada. But in the case of Caribou, featured on the Canadian quarter, there are many distinct groups with unique combinations of genetic features and life history traits, resulting in the recognition of more than a dozen distinct population groups. All will be assessed by COSEWIC over the coming years, some for the third or fourth time. At this meeting, three of these population groups were assessed: Southern, Central and Northern Mountain Caribou. Together these include about 70 herds in the mountains of western Canada, from southern British Columbia and Alberta to Yukon and the Northwest Territories. Having lost 30 per cent of their range since the early 1900s, the condition of many herds has been deteriorating at an accelerating pace because of dramatic habitat changes and disturbance from industrial development, human settlement and recreation.

Southern Mountain Caribou in southeastern BC were last assessed by COSEWIC as Threatened in 2002. Since then, they have declined by 30 per cent and two herds have disappeared. Of the 15 herds comprising the Southern Mountain Caribou, 9 currently have fewer than 50 adults, and 6 herds have fewer than 15. They were assessed as Endangered at this meeting.

The situation is even more dire for Central Mountain Caribou in the Rocky Mountains of Alberta and BC, which have declined by 60 per cent in the past 10 years. They were also assessed as Endangered. Many of the Central Mountain Caribou herds occur in protected areas and parks, including Jasper and Banff National Parks. Unfortunately, even in protected areas they aren’t doing well. The last five caribou in Banff died in an avalanche in 2009.