SEATTLE (LOG NEWS SERVICE)—U.S. scientists said May 31 they would investigate why an unusual number of gray whales are washing up dead on West Coast beaches.
About 70 whales have been found dead so far this year on the coasts of California, Oregon, Washington and Alaska, the most since 2000. About five more have been discovered on British Columbia beaches. That’s a very small fraction of the total number of whales believed to have died, because most simply sink and others wash up in such remote areas they’re not recorded.
NOAA Fisheries declared the die-off an “unusual mortality event,” providing additional resources to respond to the deaths and triggering the investigation.
The eastern North Pacific gray whales were removed from the endangered species list in 1994.
The population has grown significantly in the last decade and is now estimated at
27,000 – the highest since surveys began in 1967. That has raised questions about whether their population has reached the limit of what the environment can sustain.
Another theory suggests that the loss of Arctic sea ice due to global warming is a culprit.
The whales spend their summers feeding in the Arctic before migrating 10,000 miles to winter off Mexico. Though they eat all along their route, they are typically thinning by the time they return north along the West Coast each spring.
In an average year, about 35 whales wash up in the U.S.
John Calambokidis – a research biologist with the Cascadia Research
Collective a non-profit Washington State corporation which has conducted scientific research in the fields of marine mammal and bird biology for the past 39 years – noted as the whales search farther afield for food, they’ve entered areas where they’re not normally seen so often, including San Francisco Bay and Puget Sound. That puts them at higher risk of being struck by ships or entangled in fishing gear.
Four of the 10 gray whales found dead near San Francisco this year were struck by ships, and a number of shipping companies have slowed their vessels in the area to avoid collisions.