Finney says the decline was hastened by commercial catches, which deprived the lake of nutrients needed by subsequent generations of salmon. The findings have important implications for commercial fisheries management in Alaska. Traditionally, fisheries managers assumed the environment was constant when they calculated the maximum number of salmon fishermen could harvest. The study suggests a need for new, flexible management policies that take climate and lake nutrient levels into account. Higher levels of nutrients support more juvenile salmon.
More younger salmon survive, and more salmon eventually come back and die, releasing more nutrients.
This positive feedback can increase the carrying capacity of the freshwater system. While salmon runs in lakes on Kodiak Island seemed to have a built-in dependence on nutrients from decaying salmon, lakes studied near Bristol Bay continued to produce large numbers of sockeyes despite large catches by commercial fishermen. One possible reason may be that the boost is small compared to nutrients coming from other sources. The Alaska Sea Grant College Program is a marine research, education and outreach service headquartered at the University of Alaska Fairbanks, School of Fisheries and Ocean Sciences. Sea Grant is funded by the National Oceanic and Atmospheric Administration in partnership with the state of Alaska and private industry.