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dc.contributor.authorJorgensen, Christian
dc.contributor.authorHolt, Rebecca E.
dc.date.accessioned2018-12-05T22:12:19Z
dc.date.available2018-12-05T22:12:19Z
dc.date.issued2013
dc.identifier.issn1385-1101
dc.identifier.doi10.1016/j.seares.2012.04.003
dc.identifier.urihttp://hdl.handle.net/10072/173258
dc.description.abstractA stronger focus on natural mortality may be required to better understand contemporary changes in fish life histories and behaviour and their responses to anthropogenic drivers. Firstly, natural mortality is the selection under which fish evolved in the first place, so a theoretical understanding of effects of natural mortality alone is needed. Secondly, due to trade-offs, most organismal functions can only be achieved at some cost in terms of survival. Several trade-offs might need to be analysed simultaneously with effects on natural mortality being a common currency. Thirdly, there is scattered evidence that natural mortality has been increasing, some would say dramatically, in some fished stocks, which begs explanations. Fourthly, natural mortality most often implies transfer of mass and energy from one species to another, and therefore has foodweb and ecosystem consequences. We therefore analyse a model for evolution of fish life histories and behaviour, where state-dependent energy-allocation and growth strategies are found by optimization. Natural mortality is split into five different components, each specified as the outcome of individual traits and ecological trade-offs: a fixed baseline mortality; size-dependent predation; risk-dependent growth strategy; a fixed mortality when sexually mature; and mortality increasing with reproductive investment. The analysis is repeated with and without fishing. Each component of natural mortality has consequences for optimal life history strategies. Beyond earlier models, we show i) how the two types of reproductive mortality sometimes have similar and sometimes contrasting effects on life history evolution, ii) how ecosystem properties such as food availability and predation levels have stronger effects on optimal strategies than changing other mortality components, and iii) how expected changes in risk-dependent growth strategies are highly variable depending on the type of mortality changed.
dc.description.peerreviewedYes
dc.languageEnglish
dc.language.isoeng
dc.publisherElsevier Science
dc.relation.ispartofpagefrom8
dc.relation.ispartofpageto18
dc.relation.ispartofjournalJournal of Sea Research
dc.relation.ispartofvolume75
dc.subject.fieldofresearchEcology not elsewhere classified
dc.subject.fieldofresearchOceanography
dc.subject.fieldofresearchEcology
dc.subject.fieldofresearchcode060299
dc.subject.fieldofresearchcode0405
dc.subject.fieldofresearchcode0602
dc.titleNatural mortality: Its ecology, how it shapes fish life histories, and why it may be increased by fishing
dc.typeJournal article
dc.type.descriptionC1 - Articles
dc.type.codeC - Journal Articles
dcterms.licensehttp://creativecommons.org/licenses/by-nc-nd/3.0/
dc.description.versionVersion of Record (VoR)
gro.rights.copyright© 2013 Elsevier B. V.. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported (CC BY-NC-ND 3.0) License which permits unrestricted, non-commercial use, distribution and reproduction in any medium, providing that the work is properly cited.
gro.hasfulltextFull Text
gro.griffith.authorHolt, Rebecca E.


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