Alarmed by the high number of gray whales that have been washing up dead on West Coast beaches this spring, the federal government on Friday declared the troubling trend a wildlife emergency. The declaration by the National Oceanic and Atmospheric Administration - technically, the agency dubbed the deaths an "unusual mortality event" - kicks in a provision of federal law that provides funding for scientists to figure out the cause when such die-offs of marine mammals occur, from whales and dolphins in the Pacific or Atlantic to manatees off Florida.
So far this year, at least 70 gray whales have been found dead and stranded along the coasts of California, Oregon, Washington and Alaska - the most in nearly 20 years, scientists from NOAA said Friday.
In recent weeks, whales have washed up in Marin, San Francisco and San Mateo counties. On average about 35 of the giant marine mammals wash up dead on the West Coast in a year, or around three per month. Last year, 45 were found. But the average number found dead for the first five months of the year on the West Coast is 15, so this year is seeing five times the average rate. "There have been juveniles but adults as well. There have been males and females. It's been all across the board at this point," said Justin Viezbicke, NOAA's California Stranding Coordinator.
The last time this many gray whales were found dead off California, Oregon, Washington and Alaska was in 2000, when 83 had washed up by May 31. That year, 131 died. Scientists say they don't yet know why the whales are dying, although many have been found malnourished, leading to theories that warmer ocean waters from climate change might be disrupting their food supply, particularly in the Arctic.
"We are seeing lots of live gray whales in unusual locations, clearly emaciated, trying to feed," said John Calambokidis, a research biologist with the Cascadia Research Collective in Olympia, Washington. Among those unusual locations: San Francisco Bay, Los Angeles Harbor and Puget Sound, he said. Closer to shore, whales are more at risk from dying by being hit by freighters, oil tankers and other large commercial ships.
The whales that wash up dead on the shore may represent only 10 per cent of the whales that are dying in the open ocean off the West Coast. "Most whales and especially emaciated whales will tend to sink when dead," said a NOAA expert. "So the numbers that wash up represent a fraction of the total. The vast majority go unreported."