About 20 endangered beluga whales freed themselves after being stranded for several hours on the mud flats of Turnagain Arm, a law enforcement officer said Wednesday.
The National Oceanic and Atmospheric Administration got a call Tuesday afternoon that some beluga whales were spotted stranded in the arm southeast of Anchorage, agency spokeswoman Julie Speegle said.
NOAA law enforcement officer Noah Meisenheimer boarded a Piper Cub airplane with a pilot from the Alaska State Troopers to go searching for the whales. At about 7:45 p.m., the whales were seen gathered together in a small pool in the mud.
After the pilot lowered the plane from 1,000 feet to 500 feet to get a better look, Meisenheimer counted about 20 belugas on the mud flats at midchannel just west of Bird Point.
Low tide was at 6 p.m. and by this time, the tide was coming in. The white whales were wriggling about trying to get free, Meisenheimer said.
The pilot took a brief tour to look for more whales but didn't find any. When he returned to where they had seen the whales struggling in the mud, the water was higher and they spotted about 10 swimming in the general area. None seemed distressed and no dead whales were seen.
Cook Inlet belugas are endangered. The most recent survey in 2011 counted 284 whales.
The whales face the ever-present threat of being stranded in Turnagain Arm because of its long and narrow shape, requiring the animals to move quickly to deeper water once the tide goes out. The water travels about 20 miles as the arm floods and empties each tidal cycle. In June 1995, about 190 whales stranded but none died.
Some strandings, however, are deadly. In August 2004, five or six whales died when 46 stranded in the arm. About the same number are believed to have died in 1999, when about 50 whales stranded.
The reasons for whale strandings are not fully understood, said Rod Hobbs, beluga project leader for the National Marine Mammal Lab in Seattle. It's possible the whales find themselves in the wrong place at the wrong time after chasing salmon or avoiding killer whales, he said.
What scientists do know is that when belugas become stranded they tend to gather together in the mud and move around to create a small pool, where water coursing over their flukes and flippers helps keep them cool, he said.
The whales this time likely were stuck for about four hours, Hobbs said.
"They go up and down those arms of the Inlet a couple of times a day with the tides," he said. "Every once in a while something happens."