By Yereth Rosen
ANCHORAGE, Alaska (Reuters) - Alaska's summer heat wave has been pleasant for humans but punitive for some of its fish.
Overheated water has been blamed for large die-offs of hatchery trout and salmon stocks in at least two parts of the state as hot, dry weather has set in, according to the Alaska Department of Fish and Game.
Hundreds of grayling and rainbow trout died in June after being placed in a Fairbanks lake, the department reported. An unusually cold spring caused lake ice to linger much longer than normal, before the water quickly became too warm, department biologist April Behr said.
Surface temperatures in the lake rose to about 76 degrees Fahrenheit (24 degrees Celsius), she said. The precise number of dead fish was not yet known. "We picked up several hundred," she said.
A similar incident occurred in mid-July at the Crystal Lake Hatchery south of Petersburg in southeast Alaska.
An estimated 1,100 hatchery king salmon died while returning to a lake to spawn, local public radio station KFSK reported. Fish and Game sport fish biologist Doug Fleming told the radio station that air temperatures were in the 80s at the time.
Record-breaking heat has also created elevated wildfire risks in Alaska, even in the normally rain-soaked Tongass National Forest in the state's southeastern panhandle.
Wildfires have charred more than a million acres across Alaska, according to state and federal wildfire managers, more than the five-year season-total annual average of 952,113 acres. Some 75 active fires were still burning on Friday, with much of the fire season still to come.
WILDFIRE INQUIRY LAUNCHED
One blaze that has consumed 85,000 acres near Fairbanks has drawn congressional scrutiny. The so-called Stuart Creek 2 Fire was sparked in June by Army artillery training conducted in hot, dry conditions against the advice of federal wildfire managers, according to the U.S. Bureau of Land Management.
U.S. Senator Lisa Murkowski, an Alaska Republican, said on Thursday she had launched an inquiry into the origins of that blaze, which prompted the evacuation of hundreds of area residents and racked up a firefighting bill of $19 million.
She persuaded the Senate Defense Appropriations subcommittee to insert language into a budget bill requiring the Army to explain its decision to hold the artillery exercise.
Numerous heat records have fallen this year around the state throughout the summer.
Fairbanks on Thursday set a new record for the total number of summer days with temperatures at 80 degrees or above in that city - 31 straight to beat the previous mark of 30 days set in 2004, the National Weather Service said.
Anchorage on Wednesday set a new benchmark for consecutive days with temperatures at 70 degrees or above, with a 14-day run that bested the previous record, set in 2004, by one day.
Daily record temperatures have been set over the past week in Anchorage, Valdez, McGrath and King Salmon. Numerous other communities saw record highs earlier in the summer.
The unusual warm conditions derive from a persistent weather pattern high in the atmosphere above Alaska, according to the National Weather Service.
The heat is expected to gradually give way to cooler, rainier conditions more typical for August as a new pressure system builds over the Bering Sea, said Dan Samelson, a Weather Service meteorologist.
"It'll be a little bit slow in coming," he said.
(Editing by Steve Gorman and Prudence Crowther)