Little Teslin Lake Whitefish species pair: Consultations on listing under the Species at Risk Act

Engagement

Let your opinions be heard

Canada’s Species at Risk Act (SARA) provides legal protection for wildlife species at risk to conserve biological diversity. It also acknowledges that all Canadians have a role to play in the conservation of wildlife species. The Little Teslin Lake populations of small-bodied European Whitefish and large-bodied Lake Whitefish are being considered for addition to the List of Species at Risk as threatened. We would like to hear your opinion, comments, and suggestions on the possible ecological, cultural, social, and economic impacts and benefits of listing this species under SARA to inform a listing decision.

Adding a species to the List of Wildlife Species at Risk

The process of listing a species under SARA is triggered by a status assessment by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC) and ends with a Government of Canada decision on whether or not to add a species to the List of Species at Risk. Public engagement is conducted to gather the opinions of Canadians, and is an important step in this process.

Facts about the Little Teslin whitefish species pair

Across Canada, whitefish species have adapted to their environments in unique ways, creating distinct populations in individual lakes. In a few lakes, there are unique “species pairs,” where two distinct forms of whitefish live together but remain genetically separate. In the Yukon, whitefish species pairs have been found in three lakes; Dezadeash, Squanga and Little Teslin (Figure 2). Little Teslin Lake has separate small-bodied and large-bodied populations, descended either from originally-present Lake Whitefish ancestors or from European Whitefish that dispersed across the Beringian land bridge from Siberia. The Little Teslin Lake species pair is unique to this lake, and exists nowhere else in the world.

The Little Teslin whitefish species pair live in the same lake but do not interbreed. The small-bodied population matures faster, lives in the open waters of the lake, and feeds on plankton. In contrast, the large-bodied population lives near the bottom and feeds on larger prey such as clams, snails and aquatic insects. Differences in spawning location and timing are likely, but not currently known.

The existence of these two separate forms in Little Teslin Lake can be disrupted if a new aquatic species is introduced. For example, in the Yukon, whitefish species pairs are only found in lakes without Least Cisco, a species that competes with small-bodied whitefish for food. In Ontario, the introduction of cisco into a lake with a whitefish species pair led to the rapid extinction of the small-bodied form. Other invasive species, such as Zebra Mussels and Quagga Mussels, could also harm the ecosystem and disrupt the balance needed to maintain these unique whitefish pairs.