Delineation of stock assessment units for northern shrimp in the Estuary and northern Gulf of St. Lawrence

Abstract

In the Estuary and Gulf of St. Lawrence, four assessment units have been used since 1993 for the assessment of northern shrimp stocks, namely the Estuary, Sept-Iles, Anticosti and Esquiman areas. These stock assessment units correspond to locations where high concentrations of shrimp are generally observed during the research survey. Information on northern shrimp abundance and the distribution of fishing effort over the last several decades suggests that the stock assessment units in the Estuary and northern Gulf of St. Lawrence need to be changed. A new delineation of the stock assessment units is proposed and supported by findings from a population genomics study. The stock indicators have been updated based on the new delineation, which provides an improved correspondence between assessment units and biological units.