Marine mammal experts studying dead sperm whale

Johanna Vollenweider/NOAA A team of marine mammal experts perform a necropsy on a male sperm whale.

A team of marine mammal specialist, led by NOAA Fisheries veterinarian Kate Savage, is studying the remains of a 48-foot long sperm whale that washed up on a beach in Alaska’s famed Inside Passage in Southeast Alaska.

Sperm whales, who have been listed as endangered under the Endangered Species Act since 1970, usually are found in deeper offshore waters. This one was found beached on the east side of Lynn Canal, north of Berners Bay near Juneau.

NOAA officials said that necropsy findings indicate the whale died from trauma consistent with a ship strike. The team documented fractured vertebrae and three deep propeller slices into the whale’s side. The team also found that the whale’s stomach contents were a lot of squid beaks, but no plastic and no sablefish parts. Multiple sperm whales have been found dead with significant amount of plastic in their stomachs in recent years, go the team was pleased not to find any in this whale.

Savage said the deceased whale provided an exceptional opportunity for a marine mammal biologist.

“There are a lot of unknowns around sperm whale biology and life history in Alaskan waters, so we could learn a lot from this stranding,” she said.

The team led by Savage includes others from NOAA Fisheries, the Alaska Department of Fish and Game, Sitka Stranding Network and the University of Alaska.

On March 20 the team collected the whale’s teeth to determine age, blubber to check for contaminants and a variety of tissue samples to examine DNA and other health indicators.

Only two other sperm whales have been necropsied in Alaska since 1990. The first was a partial necropsy of a whale that became stranded in Resurrection Bay in 2006, and the second was a calf stranded near Homer in 2009.

Researchers with the Southeast Alaska Sperm Whale Avoidance Project are working to determine if this whale is one of three known individual whales to frequent Chatham Strait and Lynn Canal, based on tagging data collected over the past five years. SEASWAP is a collaboration of commercial fishermen, scientists and fisheries managers who use acoustics, tagging, tissue sampling and photo-identification to learn more about sperm whales in Southeast Alaska. Their goal is to test deterrents and strategies to minimize interactions between whales and fishermen.