Understanding and Estimating Effective Population Size for Practical Application in Marine Species Management |
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| Authors: | MATTHEW P. HARE LEONARD NUNNEY MICHAEL K. SCHWARTZ DANIEL E. RUZZANTE MARTHA BURFORD ROBIN S. WAPLES KRISTEN RUEGG FRISO PALSTRA |
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| Affiliation: | 1. Department of Natural Resources, Cornell University, Ithaca NY 14853, U.S.A., email mph75@cornell.edu;2. Department of Biology, 3306 Spieth Hall, University of California, Riverside, CA 92521, U.S.A.;3. USDAForest Service, Rocky Mountain Research Station, 800 E. Beckwith Avenue, Missoula, MT 59801, U.S.A.;4. Department of Biology, Dalhousie University, Halifax, Nova Scotia B3H 4J1, Canada;5. Department of Natural Resources, Cornell University, Ithaca, NY 14853, U.S.A.;6. NOAA Fisheries, Northwest Fisheries Science Center, Seattle, WA 98112, U.S.A.;7. Department of Biology, Hopkins Marine Station, Stanford University, 120 Oceanview Boulevard, Pacific Grove, CA 93950, U.S.A. |
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| Abstract: | Abstract: Effective population size (Ne) determines the strength of genetic drift in a population and has long been recognized as an important parameter for evaluating conservation status and threats to genetic health of populations. Specifically, an estimate of Ne is crucial to management because it integrates genetic effects with the life history of the species, allowing for predictions of a population's current and future viability. Nevertheless, compared with ecological and demographic parameters, Ne has had limited influence on species management, beyond its application in very small populations. Recent developments have substantially improved Ne estimation; however, some obstacles remain for the practical application of Ne estimates. For example, the need to define the spatial and temporal scale of measurement makes the concept complex and sometimes difficult to interpret. We reviewed approaches to estimation of Ne over both long‐term and contemporary time frames, clarifying their interpretations with respect to local populations and the global metapopulation. We describe multiple experimental factors affecting robustness of contemporary Ne estimates and suggest that different sampling designs can be combined to compare largely independent measures of Ne for improved confidence in the result. Large populations with moderate gene flow pose the greatest challenges to robust estimation of contemporary Ne and require careful consideration of sampling and analysis to minimize estimator bias. We emphasize the practical utility of estimating Ne by highlighting its relevance to the adaptive potential of a population and describing applications in management of marine populations, where the focus is not always on critically endangered populations. Two cases discussed include the mechanisms generating Ne estimates many orders of magnitude lower than census N in harvested marine fishes and the predicted reduction in Ne from hatchery‐based population supplementation. |
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| Keywords: | contemporary Ne genetic drift hatchery‐based supplementation inbreeding Ne long‐term Ne metapopulation Ne/N ratio selection temporal method variance Ne deriva gé nica metapoblació n mé todo temporal N
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contempó ranea N
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endogá mica N
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varianza proporció n Ne/N selecció n suplementació n basada en criaderos |
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