Research Document 2019/002

Redfish (Sebastes mentella and S. fasciatus) stocks status in Unit 1 in 2017

By Senay, C., Gauthier, J., Bourdages, H., Brassard, C., Duplisea, D., and Ouellette-Plante, J.

Abstract

Redfish fishing in the Gulf of St. Lawrence (Unit 1) targets two species, Sebastes mentella and S. fasciatus. Between the mid-1950s and 1993, the fishery was marked by three intense exploitation episodes that were closely linked to recruitment of one or several strong year-classes. A sudden drop in landings and the absence of recruitment led to the establishment of a moratorium in 1995. Redfish fishing is still under a moratorium in Unit 1 and an index fishery has been authorized since 1998. Total allowable catch (TAC) for this fishery is 2,000 tons per management year since 1999.

According to surveys conducted in the Gulf of St. Lawrence, abundance and biomass indices for Sebastes mentella and S. fasciatus were low and stable since the mid-1990s. Juvenile Redfish abundance from the 2011 to 2013 cohorts has increased dramatically in research surveys. These cohorts are the most abundant ever observed. These individuals are largely dominated by S. mentella and show the genetic signature of the Units 1 and 2 adult population. In the summer 2017, the 2011 to 2013 Redfish cohorts’ modal size was 20 cm. If the anticipated growth of these cohorts continues, close to 50% of the individuals (59% biomass) of the 2011 cohort should be larger than 22 cm in 2018, the minimum regulatory size. By 2020, 51% of the individuals of the cohort (62% biomass) should be larger than 25 cm. In Unit 1, total minimum trawlable biomass of Redfish greater than 22 cm in length began to increase in 2017. It was estimated to be 349,000 tons and 89,000 tons for S. mentella and S. fasciatus, respectively. However, biomass of Redfish greater than 25 cm in length has not yet started to increase in survey. By 2019, biomass of Redfish greater than 25 cm is expected to increase substantially. Prospects for Redfish stocks are extremely positive. The strong recruitment and biomass increase may allow higher catches of S. mentella in Unit 1 by 2018, while it is preferable to remain cautious for S. fasciatus.

In support of the Redfish stock assessment survey (S. mentella and S. fasciatus) of Units 1 and 2 in 2017, this document describes the data and methods use for the stocks of Unit 1 under the responsibility of the Science Branch, Quebec Region of the Department of Fisheries and Oceans.

Research Document 2019/002 (PDF, 7,531 KB)

Accessibility Notice

This document is available in PDF format. If the document is not accessible to you, please contact the Secretariat to obtain another appropriate format, such as regular print, large print, Braille or audio version.