Advancing spatio-temporal stock assessment models to integrate high-resolution seafloor mapping data in order to achieve sustainable harvest strategies for Canadian shellfish

The ocean is an integral part of Canada's culture, environment, public health and economy. The ocean economy employs more than 315,000 Canadians and contributes more than $26 billion of gross domestic product (GDP) each year. Atlantic Canada's commercial fishery is built primarily from benthic shellfish, valued at over $3 billion in 2019. The importance of incorporating spatial information into the assessment and management of these shellfish populations has long been recognized. Due to the strong association with substrate type, density distributions of benthic shellfish stocks can be relatively well represented by seafloor habitat maps. These maps, combined with geospatial fisheries data, have tremendous potential to improve our understanding of the spatial patterns and complexities of shellfish population dynamics and responses to fishing. The goals of this partnership between Clearwater Seafoods (Clearwater), E'sukutimkewey, and Fisheries and Oceans Canada (DFO) are to: A) develop the statistical framework and supporting software needed to integrate high-resolution data streams into the next generation of spatio-temporal stock assessment models; and B) devise more sustainable harvest strategies for benthic shellfish (and other) species by incorporating new knowledge of spatio-temporal variability in recovery and other relevant processes. Using Arctic surfclam (Mactromeris polynyma) as a case study, this partnership will give rise to the following outcomes and impacts: 1) full integration of high-resolution environmental data into stock assessment models and associated harvest strategy processes; 2) greater confidence in the setting of sustainable removal levels; 3) better understanding of how ecosystem-based rotational fishing strategies can be implemented; and 4) knowledge- and technology-transfer to stock assessment scientists and fisheries managers across Canada. This will directly contribute to the additional demands for fisheries science under the new Fish Stocks Provisions of the Fisheries Act (Formally Bill C-68).