Atlantic whitefish  (Coregonus huntsmani)

The exact reasons for the historical decline in Atlantic whitefish are not entirely clear, but a major factor is likely to be the extensive construction of dams throughout the principal rivers and streams of south-western Nova Scotia which inhibit this species’ spawning migration. Damming and additional threats, such as unregulated fishing and increased acidification of the water from acid rain, are almost certainly responsible for the recent extirpation of the Atlantic whitefish from the Tusket River drainage (4). The presence of dams within the Petite Rivière drainage is also likely to have contributed to the only surviving Atlantic whitefish population’s current landlocked status (3) (4). Despite the protection of the remaining populations, they are accidently caught by recreational anglers, and are also threatened by acidification and the unauthorised introduction and spread of non-native fish species, such as the smallmouth bass (4).

Several conservation measures are in place for the Atlantic whitefish. Since 1970, fishing of this species has been illegal in Nova Scotia under the federal Fisheries Act (3). This was followed in 1984 by this species’ designation as ‘endangered’ by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC), and later under Schedule 1 of the 2003 Species at Risk Act (SARA) (2) (4). Both of these designations require initiatives to protect this species and its habitat, and promote its recovery (2) (4). To facilitate these objectives, a recovery plan is underway, which has resulted in the creation of monitoring programs and the successful development of captive breeding techniques, along with plans for reintroductions (3). One of the key factors to ensure the survival of the imperilled Atlantic whitefish is the reestablishment of anadromous populations, both in the Petite Rivière drainage and in areas of this species’ former range. This will require the development of techniques to bypass the current barriers presented by hydroelectric dams (4).