Selective fishing induces density-dependent growth

Abstract

Over the last decades, views on fisheries management have oscillated between alarm and trust in management progress. The predominant policy for remedying the world fishing crisis aims at maximum sustainable yield (MSY) by adjusting gear selectivity and fishing effort. Here we report a case study on how striving for higher yields from the Eastern Baltic cod stock by increasing selectivity has become exceedingly detrimental for its productivity. Although there is a successive increase in numbers of undersized fish, growth potential is severely reduced, and fishing mortality in fishable size has increased. Once density-dependent growth is introduced, the process is self-enforcing as long as the recruitment remains stable. Our findings suggest that policies focusing on maximum yield while targeting greater sizes are risky and should instead prioritize catch rates over yield. Disregarding the underlying population structure may jeopardize stock productivity, with dire consequences for the fishing industry and ecosystem structure and function.

Published in

Nature Communications
2014, Volume: 5, article number: 4152Publisher: NATURE PUBLISHING GROUP

SLU Authors

• Svedäng, Henrik

  • Department of Aquatic Resources (SLU Aqua), Swedish University of Agricultural Sciences
    

Sustainable Development Goals

SDG14 Life below water


UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1038/ncomms5152

Permanent link to this page (URI)

https://res.slu.se/id/publ/62064