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Research article - Peer-reviewed, 2021

Size-selective competition between cod and pelagic fisheries for prey

Kulatska, Nataliia; Woods, Pamela J.; Elvarsson, Bjarki Thor; Bartolino, Valerio;

Abstract

Predators often predate on a limited size range of prey, which may or may not overlap with size ranges of same prey targeted by fisheries. When they do overlap, the effect of competition over that prey is immediate, as the predator removes prey, which are at the same time suitable for the fishery. However, if the predator consumes the same prey species as the fishery, but targets smaller prey sizes, this predation on smaller sizes may result in a potential loss of future, rather than current, fishing opportunities. Comparative analyses of predator size preference and fisheries selectivity are scarce, despite their relevance in the context of integrated management of fish populations. We evaluated how size-selective cod predation influences the dynamics of sprat and herring in the Baltic Sea, as well as the competition with pelagic fisheries through immediate and delayed effects. We found a large overlap (30-60%) between prey lengths targeted by cod and fisheries, which was largest in the 1970s-1980s, when cod had higher abundance and was larger in size. Cod generally consumes herring and sprat, which are smaller than those caught by the fisheries, causing both immediate and delayed effects on prey biomass available for the fisheries.

Keywords

Baltic Sea; competition with fisheries; mortality; multi-species model; size-selective predation

Published in

ICES Journal of Marine Science

2021, volume: 78, number: 5, pages: 1900-1908
Publisher: OXFORD UNIV PRESS

Authors' information

Swedish University of Agricultural Sciences, Department of Aquatic Resources
Stockholm University
Woods, Pamela J.
Marine and Freshwater Research Institute
Elvarsson, Bjarki Thor
Marine and Freshwater Research Institute (MFRI)
Swedish University of Agricultural Sciences, Department of Aquatic Resources

UKÄ Subject classification

Fish and Aquacultural Science

Publication Identifiers

DOI: https://doi.org/10.1093/icesjms/fsab094

URI (permanent link to this page)

https://res.slu.se/id/publ/113837