Rare Fin Whale Likely Killed By Ship Strike; Fifth Whale Carcass To Wash Ashore In 3 Weeks

SAUSALITO (CBS SF) -- An endangered fin whale that washed ashore in San Francisco this weekend likely suffered fatal injury from a ship strike, officials from the Marine Mammal Center announced Saturday.

Teams from the California Academy of Sciences and U.C. Santa Cruz helped investigate the animal's death in a necropsy conducted on Saturday afternoon.

"By investigating deaths like this, we can learn more about how human activity and changing environmental trends are impacting large whales," said Barbie Halaska, Necropsy Manager for The Marine Mammal Center. "Ship strikes are the biggest threat fin whales face, so this investigation helps us understand the challenges these animals face and inform decision-makers so we can safely share the ocean with marine wildlife."

Initially reported to center early Friday morning by the U.S. Coast Guard, the whale carcass was sighted a few miles offshore west of the Golden Gate Bridge. By Friday night, it landed at Fort Funston.

During Saturday's necropsy, scientists discovered significant bruising and hemorrhaging to muscle around the whale's neck vertebrae consistent with blunt force trauma due to a ship strike.

The team identified the fin whale as a 46-foot juvenile male that was moderately decomposed. Experts noted the whale was of average body condition based on the blubber layer and internal fat levels. The whale also had a stomach full of krill, a primary food source.

The Marine Mammal Center has responded to six other fin whale deaths in its 46-year history. Five of the six died from trauma due to ship strike.

The fin whale -- typically found offshore in deep waters -- is the second-largest species of whale and is listed as endangered under the Endangered Species Act.

The four other whale carcasses that have washed ashore in the Bay Area since March 31 have been gray whales.