Science Advisory Report 2020/017

Stock assessment of NAFO Subdivision 3Ps American Plaice in 2019

Summary

• Biomass of the stock in 2019 is estimated to be 35% of B_lim (B_lim=40% B_MSY) and therefore the stock is in the Critical Zone. The probability of being below B_lim is high (0.98). Current median fishing mortality is estimated to be 24% of F_lim and the probability of being above F_lim (F_MSY) is low (0.03).
• The stock has shown little or no growth since 2008.
• Despite the appearance of relatively strong year classes in 2008 and 2013, these have resulted in few fish greater than 30 cm, indicating that this recruitment has not survived to older ages.
• Bottom temperatures in 3Ps remain above normal which may contribute to low productivity in American Plaice. The spring bloom continues to be reduced in magnitude. Zooplankton biomass in 3Ps was near normal in 2017 and 2018 after four years of low production, with an increased proportion of smaller species. Data were unavailable from 2019. Ongoing warming trends, together with an increased dominance of warm water fishes, indicate that this ecosystem continues to experience structural changes.
• Projections of stock size were conducted to the beginning of 2023 under conditions of zero catch, current F, current F plus 15%, and current F minus 15%. Although the stock is projected to grow under all scenarios, at the end of the projection period there is a high probability(>0.88) of being below B_lim in all cases.
• There is no level of catch which gives a high (95%) probability of stock growth.
• Consistency with the DFO decision-making framework incorporating the Precautionary Approach requires that removals from all sources must be kept at the lowest possible level until the stock clears the critical zone.

This Science Advisory Report is from the November 19-22, 2019 3Ps cod and 3Ps American Plaice Stock Assessment. Additional publications from this meeting will be posted on the Fisheries and Oceans Canada (DFO) Science Advisory Schedule as they become available.

Science Advisory Report 2020/017 (PDF, 622 KB)

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