Avoiding Domestication of an Endangered Species: Conservation Culture of California’s Delta Smelt

Jeff Schaeffer | AFS Co-Chief Science Editor. E-mail: [email protected]

This article highlights efforts to conserve Delta Smelt Hypomesus transpacificus, an endangered species threatened by habitat loss and drought in the Sacramento/San Joaquin Delta. This is an important topic because several social media communications have blamed Delta Smelt for exacerbating California’s current drought issues. This has made habitat conservation more difficult and raised the possibility that the species may need to be maintained in captivity for at least some time. This manuscript examined the intricacies of Delta Smelt spawning behavior and found that captive individuals of both sexes spawned naturally multiple times per season, but under free mating conditions, Delta Smelt did not prefer to mate with unrelated individuals. This resulted in a small but significant loss of genetic diversity in larvae and suggests that conservationists may have to pursue genetic diversity actively via avoidance of domestication. This is a linchpin for maintaining populations of cultured fish that are as close to wild fish as feasible and will greatly assist repatriation efforts if they are needed. This information was a top priority for Delta Smelt conservation, but the ideas are likely applicable to other species cultured for conservation. REFERENCE LaCava, M. K. Fisch, M. Nagel, J. C. Lindberg, B. May, and A. J. Finger. 2015. Spawning behavior of cultured Delta Smelt in a conservation hatchery. North American Journal of Aquaculture 77:255-266. dx.doi.org/10.1080/15222055.2015.1007192