Fish distribution and partial recruitment: the case of eastern Scotian Shelf cod

Abstract

The distribution-at-age of Gadus morhua in NAFO Subdiv. 4Vs and 4W was investigated as part of a study to determine possible mechanisms for differences in partial recruitment (PR) among fishing fleets. Young fish (ages 1-4) were more abundant on shallow banks in the south and west of the study area and were found at higher temperatures. Older fish (age 5+) were found at progressively greater depths toward the N and E and at colder temperatures. Distributions of cod with depth and temperature difference from the average conditions in the survey area indicating that cod sought areas with specific conditions. Longline fishing effort was concentrated in areas where older fish were more abundant while otter trawl effort was concentrated in areas where middle aged fish were more abundant. -from Author