With the exception of some western Alaska stocks, Alaska's salmon populations are numerically healthy. However, even fisheries on abundant stocks are suffering economically due to sharp declines in the value of the catch. The abundance of Alaskan salmon stocks has fluctuated greatly, both in modern times and prehistorically. These fluctuations are thought to be caused by multi-decadal changes in environmental conditions over large areas that affect many other species as well as salmon. Forecasts of salmon returns are not very reliable, and the potential for significant improvement in their accuracy is low in the short term. A viable fishing industry must be able to adapt to dramatic, persistent, and unanticipated changes in harvest levels. Nonetheless, Alaska's salmon stocks should continue to produce healthy harvests for the foreseeable future, barring significant damage to their habitat either via local activities or global warming
