An Investigation of the Effects of Uncertainty on Canadian Harp Seal Management
This study investigates the behaviour of the Canadian government's current management procedures for harp seals. These procedures are described by Fisheries and Oceans Canada as using both the Precautionary Approach and Objective Based Fisheries Management. Employing a similar underlying population modelling approach, we simulated the effects of uncertainty involving bias in estimates of human induced mortality, natural mortality and pup production estimates. These factors may combine such that the impact on the population of a certain level of take is much greater than would be predicted from assessments derived from the government model. Nevertheless, any precautionary management regime would be expected to be robust to reasonable levels of uncertainty. Our results indicate, however, that for the range of annual total allowable catches (TAC) considered and set for Canadian commercial catches of harp seals (250,000 - 350,000) there may be circumstances under which the government's management procedures fail to meet their own conservation objectives.