ICES Journal of Marine Science: Journal du Conseil Advance Access published online on November 3, 2009
ICES Journal of Marine Science: Journal du Conseil, doi:10.1093/icesjms/fsp248
Marine reserves and the evolutionary effects of fishing on size at maturation
1 Department of Biology, University of York, PO Box 373, York YO10 5YW, UK
2 York Centre for Complex System Analysis, University of York, PO Box 373, York YO10 5YW, UK
3 Vegetationsökologie und Naturschutz, Universität Potsdam, 14469 Potsdam, Germany
4 Evolution and Ecology Program, International Institute for Applied Systems Analysis (IIASA), 2361 Laxenburg, Austria
Correspondence to T. Miethe: Present address: Max Planck Institute for Demographic Research, Konrad-Zuse-Str. 1, 18057 Rostock, Germany. tel: +44 381 2081 249; fax: +44 381 2081 549; e-mail: tanja.miethe{at}googlemail.com.
Miethe, T., Dytham, C., Dieckmann, U., and Pitchford, J. W. 2010. Marine reserves and the evolutionary effects of fishing on size at maturation. – ICES Journal of Marine Science, 67: 000–000.Size-selective fishing may induce rapid evolutionary changes in life-history traits such as size at maturation. A major concern is that these changes will reduce population biomass and detrimentally affect yield and recruitment. Although marine reserves have been proposed as a tool for fisheries management, their evolutionary implications have as yet attracted little scrutiny. A simple model is used to investigate whether marine reserves can be expected to mitigate the evolutionary impacts of fishing on maturation size. The adaptive dynamics of size at maturation are analysed based on a stage-structured population model including size-selective fishing and marine reserves with different retention rates. As has been shown before, imposing greater fishing mortality on the largest individuals promotes an evolutionary change towards smaller maturation size. In the model, protecting part of a fish stock using a marine reserve can prevent such fisheries-induced evolution, and this protection critically depends on the type and extent of movement between the reserve and the fished area. Specifically, although the frequent movement of large adults increases catches of large adult fish outside a marine reserve, it also reduces the reserve's effectiveness in preventing fisheries-induced evolution. In contrast, when there is exchange between protected and fished areas through juvenile export alone, a marine reserve can effectively prevent evolution towards smaller maturation size, but does so at the expense of reducing the yield of large adult fish. Differences in the movement behaviour of successive life stages need to be considered for marine reserves, to help make fisheries more sustainable evolutionarily.
Keywords: connectivity, fitness, life-history evolution, metapopulation, size-structured model, spillover
Received 16 December 2008; accepted 20 August 2009.