Fisheries-induced disruptive selection

JOURNAL OF THEORETICAL BIOLOGY

卷:365

Article

Landi, Pietro¹  Hui, Cang^2,3  Dieckmann, Ulf⁴ 

[1] Politecn Milan, Dept Eletron Informat & Bioengn, I-20133 Milan, Italy

[2] Univ Stellenbosch, Dept Math Sci, Ctr Invas Biol, ZA-7602 Matieland, South Africa

[3] African Inst Math Sci, ZA-7945 Muizenberg, South Africa

[4] Int Inst Appl Syst Anal, Evolut & Ecol Program, A-2361 Laxenburg, Austria

关键词: Fisheries-induced evolution;    Coevolution;    Adaptive dynamics;    Size at maturation;    Evolutionary branching;   

DOI  :  10.1016/j.jtbi.2014.10.017

来源: Elsevier

【 摘 要 】

Commercial harvesting is recognized to induce adaptive responses of life-history traits in fish populations, in particular by shifting the age and size at maturation through directional selection. In addition to such evolution of a target stock, the corresponding fishery itself may adapt, in terms of fishing policy, technological progress, fleet dynamics, and adaptive harvest The aim of this study is to assess how the interplay between natural and artificial selection, in the simplest setting in which a fishery and a target stock coevolve, can lead to disruptive selection, which in turn may cause trait diversification. To this end, we build an eco-evolutionary model for a size-structured population, in which both the stock's maturation schedule and the fishery's harvest rate are adaptive, while fishing may be subject to a selective policy based on fish size and/or maturity stage. Using numerical bifurcation analysis, we study how the potential for disruptive selection changes with fishing policy, fishing mortality, harvest specialization, life-history tradeoffs associated with early maturation, and other demographic and environmental parameters. We report the following findings. First, fisheries-induced disruptive selection is readily caused by commonly used fishing policies, and occurs even for policies that are not specific for fish size or maturity provided that the harvest is sufficiently adaptive and large individuals are targeted intensively. Second, disruptive selection is more likely in stocks in which the selective pressure for early maturation is naturally strong, provided life-history tradeoffs are sufficiently consequential. Third, when a fish stock is overexploited, fisheries targeting only large individuals might slightly increase sustainable yield by causing trait diversification (even though the resultant yield always remains lower than the maximum sustainable yield that could be obtained under low fishing mortality, without causing disruptive selection). We discuss the broader implications of our results and highlight how these can be taken into account for designing evolutionarily informed fisheries-management regimes. (C) 2014 Elsevier Ltd. All rights reserved.

【 授权许可】

Free