Use of Survey Data Trends to Obtain Biological Reference Points for Flemish Cap Cod (Gadus morhua) Stock

NAFO Sci. Coun. Studies, 19:51-58

Enrique de Cárdenas and Antonio Avila de Melo

Instituto Español de Oceanografia
Aptdo. 240, Santander, Spain

Abstract

Fluctuations in recruitment and biomass indices from surveys of the cod (Gadus morhua) stock in Div. 3M were studied for the period 1978-90. Data collected during three different survey series conducted by Canada, European Economic Community (EEC) and Union of Soviet Socialist Republics (USSR) were standardized to overcome discrepancies between the indices, and compared with the catch rates of the Faroe Islands longline fishery to observe patterns. All the stock components were found to be declining during the period of this study, and were at a depressed level in 1990. Biological reference points of Flow, Fmed and Fhigh were estimated at 0.1, 0.5 and 0.9, respectively. The critical size of the spawning stock biomass was assessed to be between 25 000 tons and 30 000 tons, although its value, obtained by July 1990 EEC survey, was 21 662 tons expressed in standardized unit.