Researchers puzzle over why beluga whales in Alaska haven’t recovered – North

New research aims to find out why highly endangered beluga whales in Alaska’s Cook Inlet have failed to recover despite protective measures.

The National Oceanic and Atmospheric Administration (NOAA) has awarded more than $1.3 million to the state for three years of research involving the white whales.

“While we know what we believe caused the initial decline, we’re not sure what’s causing the population to remain suppressed,” said Mandy Keogh, a wildlife physiologist with the Alaska Department of Fish and Game.

A population of 1,300 belugas dwindled steadily through the 1980s and early ’90s.

This beluga – or, ‘sea canary’ – washed ashore on a beach south of Anchorage in 2003. U.S. officials declared Cook Inlet belugas endangered in 2008. (AP Photo/Al Grillo)

The decline accelerated when Alaska Natives harvested nearly half the remaining 650 whales between 1994 and 1998. Subsistence hunting ended in 1999 but the population remains at only about 340 animals.

Cook Inlet belugas are one of five beluga populations in U.S. waters. Cook Inlet, named for British explorer Capt. James Cook, stretches 290 kilometres from Anchorage to the Gulf of Alaska.

Belugas feed on salmon, smaller fish, crab, shrimp, squid and clams.

Dubbed “sea canaries,” the whales make a wide range of whistles, grunts and clicks, and use echolocation to navigate under ice and find prey in murky water.

Federal officials declared Cook Inlet belugas endangered in 2008.

Analyzing teeth

The new research will supplement ongoing NOAA Fisheries research and review feeding patterns, social structure of whale pods and the effects of noise.

One new study will focus on beluga prey and habitat. Researcher will analyze teeth collected over the years from hunted or stranded belugas and measure stable isotopes to determine how feeding patterns may have changed during their lives.

“Like tree rings, teeth have annual growth layers,” Mat Wooller, chemical oceanography professor at the University of Alaska Fairbanks, said in a statement. “Measuring isotopes in these growth layers can reveal how whales’ feeding habits have changed over the life of an animal.”

Chemical signatures in teeth, Keogh said, can reveal whether belugas ate fish in the water column or prey along the ocean floor.

Researcher placing a satellite transmitter onto a female beluga whale in Cook Inlet in 2000. (AP Photo/National Oceanic and Atmospheric Administration)

Streams within Cook Inlet have unique…

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