Hatchery Genetic Management Techniques for Endangered Species

Fish hatcheries designed to produce captive fish to supplement wild populations are considered powerful tools for species conservation.  Because genetic diversity may deteriorate in captive populations due to accumulation of inbreeding, adaptation to captivity and reduced effective population size, many hatcheries implement genetic management plans in an attempt to preserve the genetic health of the species.  This study reviews the current hatchery genetic management literature and describes the implementation of a genetic management plan for a captive refugial population of delta smelt (Hypomesus transpacificus).  In this context, a captive refugial population is defined as a genetically managed captive population that is designed to preserve a wild endangered population by acting as a manmade refugium.  The goal of the refugial population is to act as a genetic bank in the event of species extinction, but currently there are no plans to reintroduce these fish to the wild.  The genetic management plan for the delta smelt refugial population entails tagging fish, molecular data collection, pedigree reconstruction, relatedness estimation and recommending fish crosses annually in an effort to minimize mean kinship and limit inbreeding in the captive population.  This method aims to equalize founder representations in an attempt to maximize the captive effective population size.  The results of this study yield insights into the practical application of genetic management plans for captive populations and conservation hatcheries.  With the incorporation of these refined techniques, captive breeding may become an increasingly effective tool in species conservation.