Genetic and Ecological Management of Pacific Salmon Fisheries for the 21st Century

ABSTRACT Based on ecological adaptation theory, tremendous effort is being spent on measures that are eliminating salmon hatcheries and fishing opportunities with the intention of protecting wild runs deemed to be of particular genetic importance to the survival of the species. New research in evolutionary biology and evidence from long‐term field studies do not support these policies. Natural ecosystem variability and the complex life histories of salmon argue instead for a model based on epigenetic and phenotypic plasticity coherent with neutrality theory. Under a plasticity model, hatcheries managed within the carrying capacity of recipient streams and according to best genetic and rearing practices are not predicted to represent a threat to wild salmon, consistent with observations from the field. In addition, the scale of over‐fishing and habitat destruction in the 19th and 20th centuries, compounded by projected climate change, strongly suggest that closing hatcheries justified by ecological adaptation theory is likely to further undermine genetic integrity, ecosystem productivity, and economic value of salmon, and is unlikely to result in exploitable (recreational and commercial) populations as seen in the past. Fisheries research that considers a full range of evolutionary, ecological, and social considerations is more likely to inform policy that addresses diverse values associated with Pacific salmon.