Consequences of Seven Years of Genetic Management in a Conservation Hatchery for Delta Smelt

The Delta Smelt is an iconic federally threatened species endemic to the Sacramento-San Joaquin Bay-Delta that has declined precipitously within the last few decades. To provide an insurance policy against extinction of Delta Smelt in the wild, a refuge poulation was founded in 2006. This refuge population is maintained at the UC Davis Fish Conservation and Culture Laboratory (FCCL) in Byron, California. The FCCL population is intensively genetically managed, with the overriding goal of maintaining a captive population that is as genetically and phenotypically similar to the wild population as possible. This goal is achieved by making single pair crosses that minimize kinship, incorporating of wild fish into the population each year, and annual genetic monitoring using microsatellite markers. Thus far, after eight generations, the mean inbreeding of the FCCL population is low (<0.001), genetic diversity has been maintained relative to the wild population, and differentiation from the wild population is low. However with each subsequent generation, mean kinship increases and domestication selection occurs. My presentation will focus on the genetic management of this refuge population, lessons learned, mistakes made, and implications for future management and potential reintroduction of Delta Smelt into the wild.