Ship strike killed gray whale found dead in Bay Area, scientists say

SAN FRANCISCO (KTVU) - A team of marine biologists confirmed that a gray whale found floating in the San Francisco Bay died after being struck by a ship. 

Scientists from The Marine Mammal Center, the world’s largest marine mammal hospital, were investigating the deaths of two gray whales found around the Bay Area. So far, a total of four dead whales have been located just days apart. 
 
"It’s alarming to respond to four dead gray whales in just over a week because it really puts into perspective the current challenges faced by this species," said Dr. Pádraig Duignan, Director of Pathology at The Marine Mammal Center. 
 
The marine center said malnutrition, entanglement, and trauma from ship strikes have been the most common causes of death found by researchers. 

Scientists performed necropsies, or animal autopsies, on whales found separately at Angel Island State Park and Muir Beach. 

"During the necropsy at Muir Beach, scientists discovered significant bruising and hemorrhaging to muscle around the whale’s jaw and neck vertebrae consistent with blunt force trauma due to ship strike," according to a news release from the marine center. 

Researchers found that the 41-foot adult female was in good body condition based on blubber layer and internal fat levels.
 
A team is still working to determine the cause of death for the 37-foot subadult male gray whale that was found at Angel Island State Park.

"Our team hasn’t responded to this number of dead gray whales in such a short span since 2019 when we performed a startling 13 necropsies in the San Francisco Bay Area," says Dr. Duignan. "Gray whales are ocean sentinels due to their adaptability and foraging habits, meaning they have a lot to tell us about the health of the ocean, so to see the species continue to suffer with the added threats of human interaction is a major cause for concern."