Meta-analysis reveals lower genetic diversity in overfished populations


  • Malin L. Pinsky,

    Corresponding author
    1. Department of Ecology and Evolutionary Biology, Princeton University, Princeton, NJ, USA
    2. Department of Ecology, Evolution and Natural Resources & Institute of Marine and Coastal Sciences, Rutgers University, New Brunswick, NJ, USA
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  • Stephen R. Palumbi

    1. Department of Biology, Stanford University, Pacific Grove, CA, USA
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While population declines can drive the loss of genetic diversity under some circumstances, it has been unclear whether this loss is a general consequence of overharvest in highly abundant marine fishes. We compiled data from 11 049 loci across 140 species and found that allelic richness was lower in overfished populations within 9 of 12 genera and families. A multiple linear regression showed that allelic richness was on average 12% lower (< 0.0001) in overharvested populations after accounting for the effects of body size, latitude and other factors. Heterozygosity was on average 2% lower (= 0.030). Simulations confirmed that these patterns are consistent with a recent bottleneck in abundant species and also showed that our analysis likely underestimates the loss of rare alleles by a factor of two or three. This evidence suggests that overharvest drives the decay of genetic diversity across a wide range of marine fishes. Such reductions of genetic diversity in some of the world's most abundant species may lead to a long-term impact of fishing on their evolutionary potential, particularly if abundance remains low and diversity continues to decay.