The dead gray whale discovered Wednesday night, wedged between pilings underneath Seattle’s WA State Ferries dock, was killed by a large ship propeller.

Yesterday, a necropsy exam was performed by biologists from NOAA’s marine mammal stranding network, led by Cascadia Research and Washington Department of Fish and Wildlife with support from interns, marine mammal vets and volunteers from Sno-King MMSN and Seal Sitters MMSN.

The 6 deep gashes (photo above) along the right side of the female whale caused extensive damage while the animal was alive in Puget Sound. At least one rib was sheared off. It is estimated the 30’5” juvenile died quickly and less than 36 hours prior to her discovery.

A thick, oily layer of blubber (right) and food in the intestines indicated the two - three year old whale was in excellent health. It is a bit unusual for a gray whale to be inside Puget Sound in January. The gray was assumed headed south to Baja California’s warm winter breeding grounds after a successful season feeding in the rich waters of Alaska’s Bering and Russia’s southern Chukchi seas. Watch a video here that shows typical feeding behavior of a gray whale, scooping up large mouthfuls of ocean sediment and straining invertebrates through a comb-like filter of baleen. In the spring, on their 10,000 mile roundtrip migration back north, it is common for gray whales to venture into inland waters to feast on ghost shrimp around Whidbey Island.

Washington State averages about a half-dozen gray whale strandings each year. Thanks to the Port of Seattle for providing a secure location to perform the examination. The whale will be sunk to decompose and nourish the marine ecosystem.

Read Seal Sitters “Gray Whale Facts” here.

Tags: gray whale, necropsy