A Comparison of the Dynamics of Endangered Atlantic Salmon Populations in the Maritime Provinces, Canada

A review of the conservation status of Atlantic Salmon in Canada by the Committee on the Status of Endangered Wildlife in Canada in 2010 identified five major groups (designatable units - DUs) of Atlantic Salmon in the Maritimes Provinces, four of which were assessed as “Endangered”. Although many populations within these DUs exhibited similar abundance declines, analyses of the dynamics of several of these populations revealed marked differences both within and among DUs. At-sea survival rates for the Inner Bay of Fundy (iBoF) DU are presently about an order of magnitude lower than for salmon populations in either the Southern Upland (SU) or Outer Bay of Fundy (oBoF) DUs. Analyses for two Eastern Cape Breton salmon populations did not find evidence of a recent change in at-sea survival, a pattern that was evident for the other three DUs. In contrast with results for iBoF populations, salmon production in fresh water for many SU and oBoF populations is low relative to expectations. These results highlight the need for recovery planning to occur at the individual population level, and that the expected effectiveness of recovery actions can only be evaluated in the context of the population’s overall dynamics.