Terms of Reference

Framework Review for Unit 3 Redfish: Part 1 - Data Inputs

Regional Peer Review - Maritimes Region

January 22-23, 2025

Dartmouth, NS

Chairperson: Michelle Greenlaw

Context

Redfish is a long-lived, cold water groundfish species found in both the Atlantic and Pacific oceans. In the Northwest Atlantic, two main redfish species exist: Acadian Redfish (Sebastes fasciatus) and Deepwater Redfish (Sebastes mentella). The two species are difficult to distinguish visually and are not separated in commercial or research survey catches. The Unit 3 assessment unit was established in 1993 as North Atlantic Fisheries Organization (NAFO) division 4X and Fisheries and Oceans Canada (DFO) statistical unit areas 4Wdehkl. Redfish is fished primarily using bottom trawls as part of the multi-species groundfish fishery. Prior to 2002, the status of Unit 3 Redfish was updated in a series of zonal Stock Status Reports. Since 2009, the status of Unit 3 Redfish has been updated based on the Maritimes Region Summer Ecosystem Research Vessel (RV) Survey trends in biomass and abundance in the survey trends report (e.g., DFO 2017). In October 2011, DFO conducted an assessment of Atlantic redfish stocks (DFO 2012) with the objective of defining limit reference points consistent with the DFO precautionary approach. The Unit 3 limit reference point (LRP) was determined from empirical methods because of insufficient signal in the survey. The mean mature biomass index from 1970–2011 was taken as proxy for biomass at maximum sustainable yield (BMSY), and LRP and upper stock reference (USR) as 40% and 80%, respectively. Since the development of reference points, the Summer RV Survey trends in Science Response Reports have included plots of the mature biomass index relative to the reference points and subsequent Science Response Reports have provided stock status updates since 2019.

In 2011, DFO also conducted a Recovery Potential Assessment of Redfish in the Northwest Atlantic in response to the designation of both species being designated Threatened and Special Concern by the Committee on the Status of Endangered Wildlife in Canada (COSEWIC). It was concluded that Redfish Unit 3 biomass in 2010 was approximately 2,254,000 tonnes, with the stock having a 99% chance of staying above 40% of B_MSY by 2070 based on catch levels at the time (DFO 2011).

The total allowable catch (TAC) had been set at 9,000 t until 2021 when it was reduced to 8,000 t. Landings have generally been less than half the TAC over the past 20 years. In 2022, the mature biomass index fell below the USR and the TAC has been further reduced.

Objectives

The overall objective of this regional peer review is to develop a new assessment framework for Unit 3 Redfish to provide stock status and develop biological reference points. Specifically, this meeting (Part 1) will review data inputs for use in the development of a new assessment framework:

• Review the available biological information including stock structure and species composition.
• Review the fishery independent data from the Maritimes Summer Ecosystem RV Survey including the biomass index, spatial distribution, size composition, and condition.
• Review the commercial fishery data including landings, distribution and size composition, directed and non-directed catch.
• Report on bycatch of non-target species in the redfish fishery.

Expected Publications

• Research Document

Expected Participation

• DFO Science
• DFO Resource Management
• Indigenous communities / organizations
• Provincial governments (NS, NB)
• Industry Representatives
• Non-Government Organizations
• Academics

References

• DFO. 2011. Recovery potential assessment of redfish (Sebastes fasciatus and S. mentella) in the northwest Atlantic. DFO Can. Sci. Advis. Sec., Sci. Advis. Rep. 2011/044. (Erratum: June 2013).
• DFO. 2012. Reference points for redfish (Sebastes mentella and Sebastes fasciatus) in the northwest Atlantic. DFO Can. Sci. Advis. Sec. Sci. Advis. Rep. 2012/004. (Erratum: June 2013).
• DFO. 2017. 2016 Maritimes Research Vessel Survey Trends on the Scotian Shelf and Bay of Fundy. DFO Can. Sci. Advis. Sec. Sci. Resp. 2017/004.