Interactions between cod (Gadus morhua) and deep sea shrimp (Pandalus Borealis) in the Barents Sea

For some of the most important deep sea shrimp (Pandalus borealis) areas in the Barents Sea the content of shrimp in cod (Gadus morhua) stomachs during the first part of each year in the period 1984-1990 is analysed. Total weight, frequency of occurrence and length distribution of shrimp in the cod...

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Bibliographic Details
Main Authors: Korsbrekke, Knut, Mehl, Sigbjørn, Hylen, Arvid
Format: Report
Language:English
Published: 1991
Subjects:
Online Access:http://hdl.handle.net/11250/100297
Description
Summary:For some of the most important deep sea shrimp (Pandalus borealis) areas in the Barents Sea the content of shrimp in cod (Gadus morhua) stomachs during the first part of each year in the period 1984-1990 is analysed. Total weight, frequency of occurrence and length distribution of shrimp in the cod stomachs as well as possible switching between shrimp and capelin (Mallotus villosus) is studied. The results are compared with shrimp stomach parameters (miomass and number indices and length distribution) in the same period and areas. At the end of 1986 the capelin stock was seriously depleted and the shrimp stock indices decreased by almost 70 % from 1984 to 1986. No sign of switching from capelin to shrimp was found, and the average stomach content of shrimp decreased by up to 50 % in the same period. From 1986 to 1987 the shrimp stock indices increased by 50 % and there was a marked increase in the stomach content of shrimp. The length distributions of shrimp in trawl samples and in cod stomachs had a relatively similar shape in the period, with the top point in the trawl sample distribution at a slightly larger length.