Translocation and reintroduction of native fishes: a review of bull trout Salvelinus confluentus with applications for future reintroductions

Abstract

Declines in freshwater biodiversity resulting from anthropogenic landscape and climate changes are occurring throughout North America. Reintroduction techniques including translocation, captive rearing, and artificial propagation are often used to create new populations, repatriate extirpated populations, or supplement declining populations. Bull trout Salvelinus confluentus, a salmonid endemic to the northwestern USA and southwestern Canada, experienced significant reductions in abundance and distribution throughout the 20th century, leading to its listing in the US as ‘threatened’ under the Endangered Species Act (ESA) in 1999. A variety of projects involving reintroduction or stocking of S. confluentus have occurred across the western USA and southwestern Canada. In this review, we summarize case studies involving the reintroduction of S. confluentus and use these case studies to develop recommendations and guidelines for future S. confluentus reintroductions. We recommend that the threats leading to the initial decline of S. confluentus must be adequately addressed prior to reintroduction. Further, translocation and reintroduction project documentation is essential for informing future projects.