A dead fin whale washed up on the beach at Seahurst Park in Burien on Saturday morning.
The 70-foot whale washed up at about 10:30 a.m.
Biologists were working to determine how the whale died.
"This point we are fairly convinced this was a ship strike mortality ... the whale was hit by a ship when it was still alive we see areas of bruising and blood infused into the blubber, which means the whale was alive when struck we see signs paint from a ship," said John Calambokidis, research biologist with Cascadia Research.
Biologists say fin whales are among the most susceptible to being hit by a ship because they don't dive very deeply and spend a lot of time close to the surface while they're feeding.
"We found almost a third of the whales we've examined in the last ten years show signs of being struck by ships," said Calambokidis. "So this is an increasing problem with more ships, faster, larger ships, this has become a concern for recovering some of these whale poplations."
Biologists want to examine the whale more closely so they are going to tow it away via water.