Genetic Structure of Striped Bass in the Southeastern United States and Effects from Stock Enhancement

Abstract

Understanding the genetic relationships of Striped Bass Morone saxatilis populations within and between watersheds is necessary to identify appropriate management units. Determining temporal changes in genetic relationships as well as the genetic diversity of the populations is important in understanding how stock enhancement influences population units. A suite of 12 microsatellites was used to evaluate patterns of Striped Bass gene flow both spatially and temporally across watersheds in the southeastern United States. Populations from the study watersheds were genetically diverse with the exception of the Savannah River, South Carolina–Georgia, which is recovering from a major population decline. Striped Bass in the Roanoke and Cape Fear rivers, North Carolina, represented a single population, most likely due to historical transfer stocking across the state from Roanoke River stock. Watersheds in South Carolina contained genetically distinct Striped Bass populations, although the difference between Striped Bass populations in the Ashepoo–Combahee–Edisto (ACE) and Santee–Cooper watersheds has decreased over the past 15 years, likely due to the stocking of Santee–Cooper system fish into the ACE Basin. Conversely, supportive breeding of fish from the Santee–Cooper system has helped to maintain genetic diversity of the population. Striped Bass populations in the southeastern United States are good examples of the positive and negative effects of stock enhancement that must be considered and monitored when implementing or assessing a stock enhancement program.

Received May 14, 2013; accepted March 5, 2014

ACKNOWLEDGMENTS

We thank the South Carolina Department of Natural Resources (SCDNR), Georgia Department of Natural Resources, and North Carolina Wildlife Resource Commission, Jim Bulak, and Bert Ely III for providing tissues and DNA. We also thank all members of the genetics lab at SCDNR who helped process and score samples that were used in this study. Funding was provided by the South Carolina Salt Water Recreational License Fund, U.S. Fish and Wildlife Service State Wildlife Grant program, and the Saltonstall–Kennedy Grant program. This document is contribution number 708 of the SCDNR Marine Resources Division.