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Research article2014Peer reviewed

Relative contributions of evolutionary and ecological dynamics to body size and life-history changes of herring (Clupea harengus) in the Bothnian Sea

Östman, Örjan; Karlsson, Olle; Pönni, Jukka; Kaljuste, Olavi; Aho, Teija; Gårdmark, Anna

Abstract

Question: What ecological and evolutionary processes are associated with the 25% decrease in age-specific body size of herring (Clupea harengus) in the Bothnian Sea over the last 30 years?Data: Four decades of data on length, age, and sexual maturity of individual herrings as well as environmental variables, including abundances of predators, prey and competitors, and estimates of fishing intensity/mortality from the Bothnian Sea.Search methods: Information-theoretic assessment of the relative influence of ecological and fisheries' effects on temporal changes in body growth. Probabilistic maturation reaction norms to study changes in age-specific size at maturation. Decomposition of trait variation into ecological and evolutionary contributions.Conclusions: Our evolutionary ecosystem perspective shows that both ecological and evolutionary processes are important contributors to observed phenotypic changes in this commercially exploited species. Around 60% of the decrease in age-specific body length can be attributed to increased density-dependent body growth. Evolutionary changes towards earlier maturation, owing to an indirect effect of size-selective mortality from grey seals and fisheries, account for a further 25% of the decrease in age-specific body size.

Keywords

Baltic Sea; density dependence; fisheries; grey seal; pelagic; zooplankton

Published in

Evolutionary Ecology Research
2014, volume: 16, number: 5, pages: 417-433
Publisher: EVOLUTIONARY ECOLOGY LTD

SLU Authors

UKÄ Subject classification

Fish and Aquacultural Science

Permanent link to this page (URI)

https://res.slu.se/id/publ/77139