Research Document 1997/86

1996 assessment of snow crab (Chionoecetes opilio) stock in the southern Gulf of St. Lawrence (Areas 12, 18, 19, 25/26, and Zones E and F)

By M. Hébert, E. Wade, P. DeGrâce, M. Biron, and M. Moriyasu

Abstract

The 1996 evaluation of the southern Gulf of St. Lawrence snow crab stock (Areas 12, 18, 19, and 25/26) was done using data from the commercial fishery (fishery logbooks, purchase slips from processing plants, and quota monitoring reports) and data derived from the trawl survey in Areas 18 and 19 off Cape Breton. No survey was done in Areas 12 and 25/26 in 1996. The commercial crab biomass for these areas was estimated by using trawl surveys from the previous years and fishery data from 1996.

The 1996 landings were 18,224 t in the southern Gulf of St. Lawrence (Areas 12, 19, and 25/26). The catch per unit of effort (CPUE) in the southern Gulf fishery was 46.8 kg/trap hauls and the fishing effort was estimated 389,402 trap hauls.

The 1996 landings for exploratory Zones E and F were 163.5 t and 237.8 t respectively. The CUE was 60.3 kg/trap hauls in zone E and 42.4 kg/trap hauls in Zone F. Fishing effort was estimated at 2,714 trap hauls in Zone E and 5,604 trap hauls in Zone F.

The distribution of the fishing effort and landings in the southern Gulf of St. Lawrence correspond to the geographic concentrations of commercial crab estimated from the 1995 trawl survey. The harvestable biomass (B) in the southern Gulf of St. Lawrence for the 1997 fishing season was indirectly estimated at 47,146 t ( 24,988 t). The recruitment to the fishery (R) was estimated at ( 14,164 t).

Given the continuous decline tendency of the recruitment to the fishery (R), the decrease of pre-recruits (R-2) since 1993 and the aging of the population; the harvestable biomass (B) will continue to decline until the next recruitment pulses enter into the fishery within two or three years.

A strategy to set a conservative exploitation rate is recommended by avoiding highgrading activity and protecting the softshell crab because the pre-recruits (R-2 and R-3) will become more and more abundant within two or three years which result in a high incidence of softshelled crab in the commercial catch.

Complete document (PDF, 3,750 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.