Genetic monitoring of a sockeye salmon repatriation to improve interactive fisheries management
Re-establishing salmonid populations to areas historically occupied has substantial potential for conservation gains, however, such interventions also risk negatively impacting native resident stocks. An on-going reintroduction of anadromous sockeye salmon (Oncorhynchus nerka) to Skaha Lake, British Columbia is succeeding, with large numbers returning to spawn. However, a recent genetic study detected strong evidence of hybridization and introgression with native kokanee (freshwater obligate form of O. nerka), yet was unable to determine what the ultimate fitness impacts are, if any, on the population health of Skaha Lake stocks. Here we propose to use morphological and genetic analyses to better understand hybridization and introgression trends between spawning reintroduced sockeye and indigenous kokanee in Skaha Lake. Results will directly inform fisheries management decisions for minimizing fitness consequences and maintaining genetic diversity within kokanee. Additionally, these data will assist in developing size thresholds for differentiating mature kokanee and sockeye, a critical input for setting recreational fishing regulations.