Science Advisory Report 2021/034

Stock Assessment of Gulf of St. Lawrence (4RST) Atlantic Halibut in 2020

Summary

• Atlantic halibut landings have been increasing since the early 2000s and have reached the highest values since 1960. For the 2019–2020 and 2020–2021 management years, preliminary landings are 1,383 t and 1,229 t, respectively.
• The values of the abundance index for commercial-sized Atlantic halibut (over 85 cm) from scientific bottom trawl surveys in 2019 and 2020 are among the highest of the historic time series.
• The abundance index for pre-recruit Atlantic Halibut (65–85 cm) from the scientific bottom trawl surveys is at a high value since 2007.
• Catch per unit of effort in the Atlantic halibut directed longline fishery has increased from an average of about 100 kg per 1,000 hooks in the early 2000s to about 560 kg per 1,000 hooks in 2020, the highest value of the historic time series.
• The size of landed halibut is increasing and the average weight of a landed halibut has doubled between 2006 and 2020.
• The estimated relative exploitation rate, based on landings as a function of minimum trawl able biomass, is low. Preliminary analysis of tag-recapture data from the longline survey also suggests that the exploitation rate is low.
• The precautionary approach and reference points for this stock are under development.
• There is moderate evidence and high consistency among sources of evidence that the status of the stock is currently at a historically high level.
• There is robust evidence and high consistency among sources of evidence that recruitment to the fishery remains high. There is limited evidence and high consistency among sources of evidence that the exploitation rate has generally remained below the rate of biomass increase during the last 10 years, which would explain the increase in biomass of halibut over 85 cm.
• It is unlikely that maintaining current harvest levels will result in a decline in stock status. The results of this assessment do not allow the identification of a removal threshold, beyond which a decline in biomass becomes likely.

This Science Advisory Report is from the March 16-17, 2021 Regional Advisory Meeting on the Assessment of the Gulf of St. Lawrence (4RST) Atlantic halibut. 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 2021/034 (PDF, 2,263 KB)

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