Evaluation of the impacts of aquaculture and freshwater habitat on the status of Atlantic salmon stocks in Ireland

Abstract

Atlantic salmon (Salmo salar) returns to rivers in Ireland have fallen in the last decade resulting in the dramatic closure or curtailment of tradi- tional fisheries. Concerns that stocks were slow to recover prompted further investigation of all factors believed to impact on salmon. In exam- ining geographic and temporal trends in Atlantic salmon stock abundance at a River Basin Dis- trict level, the effect of salmon aquaculture sites and freshwater habitat quality as potential driv- ers of stock abundance are evaluated. This study found no correlation between the pres- ence of aquaculture and the performance of ad- jacent wild salmon stocks. Freshwater habitat quality was found to have a highly significant correlation with stock status, suggesting that it may be a key driver, implicated in the survival of individual stocks.