For a few months twice a year, the waters off California are home to gray whales moving north or south between the coast of Mexico and the Bering Sea. This year, however, it seems that fewer whales are surviving the journey north. So far this year, a total of 30 dead gray whales have washed up on the West Coast: Eight in Washington, one in Oregon and 21 in California. Those numbers are unusually high.
In Northern California, three out of four of the dead whales that have been examined so far appear to have died of starvation and the fourth was killed by a ship strike, said Barbie Halaska, a research assistant at The Marine (海洋的) Mammal Center (TMMC) , a nonprofit organization that rescues and rehabilitates (使康复) marine mammals in California. Halaska and her colleagues examined the four whales—three young whales and one adult male — and planned to examine the remaining dead whales in the region in the next couple of days.
Gray whales were once severely threatened by whalers. Only around 2,000 of them lived in the ocean in 1946, so an international agreement to stop gray whale hunting was signed in order to help the population recover. Gray whales were removed from the endangered species list in 1994 when the population reached 23,000 individuals and TMMC predicts there are now around 26,000 gray whales in the Pacific Ocean, which is about the number before the whaling boom got up steam almost 200 years ago.
Although the gray whale population has recovered to a certain degree, the number of dead whales washing up this year is alarming, Halaska said. Climate change and declining fish stocks are likely key factors in the whales' poor health, she said.
Halaska stressed that boaters and beachgoers on the West Coast should watch out for gray whales this time of year.
