Research Document 2024/065

Assessing the Productivity of the Scallop Stocks in Scallop Production Areas in the Bay of Fundy and Scallop Fishing Area 29W and the Impact of Two-Year Projection Advice

By Sameoto, J.A., Keyser, F.M., and Keith, D.M.

Abstract

The Bay of Fundy (BoF) Scallop Production Areas (SPAs) 1A, 1B, 3, 4, and 6, and Scallop Fishing Area 29 West (SFA 29W) Subareas A, B, C, and D, comprise the majority of catches from the Inshore Scallop fishery in the Fisheries and Oceans Canada Maritimes Region. Each stock area is managed using total allowable catches (TACs) and have annual analytical assessments which use modified versions of a state-space delay-difference population model that provides one-year biomass projections to inform the setting of the harvest level. However, in 2020, the DFO Science Inshore Scallop surveys were cancelled. In the absence of survey data, two-year model projections were used to inform the scallop fisheries in these areas for the 2020/21 fishing season. The objectives of this document are to evaluate the productivity of the BoF and SFA 29W stocks based on the population assessment models, to derive two-year model projections to inform the final TAC decisions for the 2020/21 season, and to evaluate the impact and uncertainty of the two-year model projections. The scallop stocks within the BoF and SFA 29W demonstrate substantial interannual variability in their productivity such that, relative to the use of one-year projections, use of two-year projections as the basis for management decisions over the long term would result in substantial risk of either loss in potential catch or overharvesting. However, for the BoF stocks and in the context of tactical one-year decision making and in the absence of 2020 survey data, these two-year projections provide context for decision making for the 2021 harvest levels. For SFA 29W, the two-year projections are not sufficiently reliable given challenges associated with projecting low biomasses; therefore, these projections are not recommended to inform the 2021 harvest levels for SFA 29W.

Research Document 2024/065 (PDF, 17,733 KB)

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