Evaluation of a provision to carry-over unused licences for eastern Canada-West Greenland bowhead whales (Balaena mysticetus) in Canada

Abstract

Eastern Canada-West Greenland (EC-WG) Bowhead whales (Balaena mysticetus) are sustainably harvested by Inuit in Canada at up to seven individuals per year, but the current bowhead whale management approach does not contain a provision for Inuit to carry-over unused strikes to subsequent years. A deterministic population model was used to evaluate whether a provision to carry-over unused strikes could be considered for bowhead co-management. To determine the sensitivity of the model to inputs, a range of parameters were used to assess uncertainty in the population dynamics. Model scenarios were simulated over a 40-year time period that examined the use of 5-year and 10-year allocation blocks with high licence totals (50 per five-year block, 100 per 10- year block). Various carry-over scenarios were used, including front-loading and back loading of harvests, and an extreme case in which all licences could be carried over through the entire allocation period. The results, which were robust to various input parameters, indicate that any of the carry over provisions that were assessed (over 5 or 10-year allocation blocks) would have little impact on the EC-WG bowhead population trajectory. The simulations investigated here do not account for increasing uncertainty related to the impacts on bowhead life history parameters resulting from environmental change (e.g., climate change) and increased anthropogenic activities (e.g., resource development, shipping). Regular population abundance estimates are needed to ensure sustainable harvest advice is consistent with Potential Biological Removal (PBR) assumptions.