Connectivity among offshore feeding areas and nearshore spawning grounds; implications for management of migratory fish

Abstract Knowing movement and structure of fish populations is a prerequisite for effective spatial fisheries management. The study evaluates migration patterns and connectivity of two groups of cod (Gadus morhua) associated with offshore feeding and nursery grounds. This was achieved by investigati...

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Bibliographic Details
Published in:ICES Journal of Marine Science
Main Authors: Sólmundsson, Jón, Jónsdóttir, Ingibjörg G, Ragnarsson, Stefán Á, Björnsson, Björn
Other Authors: Kaplan, David
Format: Article in Journal/Newspaper
Language:English
Published: Oxford University Press (OUP) 2017
Subjects:
Online Access:http://dx.doi.org/10.1093/icesjms/fsx103
http://academic.oup.com/icesjms/article-pdf/75/1/148/31236196/fsx103.pdf
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Summary:Abstract Knowing movement and structure of fish populations is a prerequisite for effective spatial fisheries management. The study evaluates migration patterns and connectivity of two groups of cod (Gadus morhua) associated with offshore feeding and nursery grounds. This was achieved by investigating (i) migration pathways of cod tagged at the feeding areas, (ii) immigration of cod to the areas based on mark-recapture data covering a period of two decades, and (iii) depth and temperature data from data storage tags (DSTs). Despite undertaking long-distance migrations after attaining sexual maturity, the cod aggregations in the two study areas appear to be largely separated from each other. This conclusion is supported by DSTs, indicating that mature fish associated with the two areas occupy different thermal-bathymetric niches. Low levels of connectivity suggest that effective spatial management in the two study areas would preserve fish of different origin. For the highly migratory adults, however, spatial management would need to focus on migration pathways and the areas where the fish are particularly vulnerable to fishing.