Atlantic Fisheries Research Document 1996/022

1995 assessment of Georges Bank yellowtail flounder

By S. Gavaris; J.J. Hunt; J.D.Nielson; F. Page

Abstract

Yellowtail flounder (Limanda ferruginea) on Georges Bank is a transboundary resource which has supported a directed Canadian fishery since 1993. Removals of flatfish specified as yellowtail flounder peaked in 1994, when 1328 t were landed. Under a newly introduced quota in 1995, landings were 397 t. The fishery is mainly prosecuted by mobile gear. Landings of unidentified flounder were substantial in 1993 and 1994 and are thought to be mainly comprised of yellowtail flounder. There have also been reports of discarding in this fishery.

To assess stock status, the most recent published US catch at age was used which included removals through 1993. Using US values for partial recruitment and estimated US total landings in 1994 and 1995, the US removals at age was updated for those years. The Canadian catch at age was constructed using Canadian length-frequency samples and by applying seasonal USA age-length keys.

Biomass decreased rapidly from 1973 to 1985, associated with a marked decline in recruitment, reaching the lowest observed level and has since only increased moderately fluctuating at about 5,000 t. Recruitment during the 1980s has been considerably poorer than that experienced during the 1970s. Only the 1987, 1990 and 1992 year-classes have been near average in the past decade. The exploitation rate on ages 4 and older has been very high, often exceeding 60% since 1973. Since the mid 1980s, the exploitation rate shows a modest declining trend, reaching the lowest observed level of about 40% in 1995. The exploitation rate on age 3 is often as high and sometimes higher than that observed on ages 4 and older. Maintaining the 1996 Canadian catch at about the 1995 Canadian allocation of 400 t should, if the USA target TAC of 385 t is not exceeded, result in a fishing mortality rate in 1996 approximating the F_0.1 = 0.29.

Complete document (PDF, 1,974 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.