Marine Biology

, Volume 161, Issue 8, pp 1905–1918 | Cite as

Wide-spread genetic variability and the paradox of effective population size in the gag, Mycteroperca microlepis, along the West Florida Shelf

  • Nathaniel K. JueEmail author
  • Felicia C. Coleman
  • Christopher C. Koenig
Original Paper


Wide-ranging marine species are often described as having a low effective population size (N e) to census size (N) ratio. This genetic phenomenon is typically attributed to large variation among individuals in reproductive success because of the high mortality rates and unpredictable environments associated with larval dispersal. In this study, we examined patterns of genetic variation in gag (Mycteroperca microlepis) on the West Florida Shelf across year classes of post-settlement juveniles and spawning adults. With no significant genetic differentiation among year classes despite varying recruitment dynamics, little evidence for chaotic genetic patchiness, and no truncation of adult genetic diversity in subsequent juvenile cohorts, there was little support for large variation among individual in reproductive success contributing to a low N e/N ratio. In fact, the consistent lack of significant differences in annual recruitment classes indicated that reproductive success among individuals was resistant to skewing. Among the various evolutionary forces that may be affecting N e, changes to demography due to fishing pressure are posited as a likely mechanism affecting current levels of genetic variation.


Reproductive Success Effective Population Size Fishing Mortality Stock Assessment Fishing Pressure 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.



The authors would like to thank Joe Travis, Don Levitan, Peter Beerli, and Bill Landing for helpful comments on this manuscript and Robert Chapman and Amy Ball for all their help with the molecular methods. We would also like to thank the numerous people who volunteered their time, effort, and assistance in collecting samples: Jeff Taylor, Terry Doyle, DJ White, Ralph Woodring, Eric Milbrandt, Kendra Willet, Joe Pfaller, Richie Kuhar, Denise Akob, Chris Smith, Ashley Carter, Amy Grosgebauer, Holly Downing, Todd Bevis, Mia Adreani, Ben Ehrman, Heather Gamper, Mark Endries, Amanda Buchanan, Libby Carnahan, and Meaghan Darcy. Mr. Ed Ellison, Dr. Aaron Adams, Pat O’Donnell, and Dr. Bill Herrnkind must also be acknowledged for their particular contributions to the project. Overall, without the assistance of all these people, this work would never have been accomplished. We would like to acknowledge the Florida State University shared High-Performance Computing facility and staff for contributions to results presented in this paper. This research has been supported by grants from the National Marine Fisheries Service (NA04NMF4540213, NA07NMF4330120, NA17FF2876), the US Environmental Protection Agency’s Science to Achieve Results (STAR) program, the Disney National Wildlife Refuge Centennial Scholar program, and the Department of Biological Science at Florida State University and by the Florida State University Coastal and Marine Laboratory (FSUCML), the FSUCML Academic Diving Program, the NOAA-NMFS laboratory in Panama City, Mote Marine Laboratory, and the Rookery Bay National Estuarine Research Reserve.

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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Nathaniel K. Jue
    • 1
    • 2
    Email author
  • Felicia C. Coleman
    • 1
  • Christopher C. Koenig
    • 1
  1. 1.Department of Biological ScienceFlorida State UniversityTallahasseeUSA
  2. 2.Department of Molecular and Cell BiologyUniversity of ConnecticutStorrsUSA

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