Death of the Salmon

摘要

Despite large reductions in fisheries harvests, wild salmon stocks in Canada are suffering high levels of mortality before they manage to reproduce—40 to 95% of fish are dying each year en route to their spawning grounds. Miller et al. (p. 214) have found a consistent association between fish mortality and a specific genomic expression signal. The past 10 years have seen unprecedentedly warm river temperatures, and salmon have died in greatest numbers in "hotspots" along the river system, possibly as a result of poor oxygen availability and disease, with some stocks being more severely affected than others.