Scientists are examining the remains of a 23-foot gray whale that washed ashore on Friday, June 14, at Sunset Beach near Warrenton. It is the latest in a series of strandings along Oregon and the West Coast this year.
Tiffany Booth at the Seaside Aquarium said the stranding marks the sixth gray whale to wash ashore this year in the Southern Washington Northern Oregon Standing Network Region. All six have been female. Four were adults, one sub-adult and one yearling.
The National Oceanic and Atmospheric Administration (NOAA) has declared the elevated rate of the gray whale strandings Unusual Mortality Event (UME), triggering a scientific investigation into the cause.
As of May 31, about 70 gray whales had stranded on the coasts of California, Oregon, Washington and Alaska, the most since 2000, when more than 100 whales stranded in what was also determined to be a UME. Two of the 70 have come ashore in Lincoln County, both in the month of April.
Outside the U.S. West Coast, British Columbia and Mexico have also recorded gray whale strandings. The eastern North Pacific gray whale population that migrates along the Pacific Coast was last estimated at about 27,000 animals.
NOAA Fisheries declared the deaths a UME on May 31 and discussed possible causes for the influx in strandings via a conference call.
“Many of the whales have been skinny and malnourished, and that suggests they may not have gotten enough to eat during their last feeding season in the Arctic," NOAA spokesman Michael Milstein said during the call.
Along with NOAA, representatives from a variety of fisheries along the West Coast participated in the discussion as well as Oceans Canada. A consensus was met in the belief that the number of strandings is likely much higher give that many whales in remote areas will simply sink as opposed to washing ashore.
The theory of global warming, leading to the loss of Arctic sea ice, was also discussed as a possible cause.
For many years, researchers noted that more whales tended to die following years when the ice melted late in the Chukchi Sea, north of the Bering Strait between Alaska and Russia. The whales had less time to eat because they were unable to access the feeding area, making for less blubber to sustain them on their next migration.
“The sea ice has been changing very quickly over the last decade or so,” Sue Moore, a biological oceanographer at the University of Washington said. “The whales may have to shift to other prey, such as krill or other things they eat.”
The last UME event was in 2000, when more than 100 whales washed up on shore. That investigation failed to identify a cause. The deaths followed strong changes in ocean conditions in the mid 90s, and Moore said warmer water patterns might have affected the availability of prey. But without accurate samples, they were unable to pinpoint a specific cause.
“It's sometimes very difficult to get to these whales in a timely fashion,” Moore said. “You can't always get the kind of samples you would need for diagnostic reasons.”
Researchers have now built up an improved group of volunteers and have asked the public to help report and respond to whale deaths.
“Scientists have been able to perform necropsies on 20 of the whales this time around,”
Deborah Fauquier, veterinary medical officer at NOAA's Office of Protected Resource said.
Scientists said they would continue to investigate whale strandings and work to determine a cause.
Max Kirkendall is the managing editor at the News Guard in Lincoln City.