Monday, August 05, 2013

Alaska's Extreme Heat Killing Fish

Abnormally high water temperatures killed at least 1100 king salmon on their way back to their hatchery. That die off is most of the 1800 adult fish expected to return for spawning. Earlier this summer another hatchery lost hundreds of grayling and rainbow trout in a Fairbanks area lake when water temperatures reached 76℉. Alaska's heat wave broke records with 14 days above 70℉ in Fairbanks and 31 days above 80℉ in Anchorage. Die-offs are not uncommon, but the magnitude and coincidence with the high temperatures was remarkable. There have been six die-offs of more than 500 fish in the last 35 years. Lack of rainfall has also impacted migrating fish that become trapped in depleted water bodies. As of August 1st the statewide salmon catch was 100 million fish. Salmon is Alaska's biggest export after oil and natural gas. The heat wave is expected to subside soon, but the state has been warming twice as fast as the rest of the United States over the past fifty years. Wildfires have consumed more than a million acres of subarctic forest and thawing permafrost is sinking native villages and buckling roads.