May 28 (UPI) — A 79-foot blue whale that washed up dead on a beach in California was struck by a boat, scientists said.
The adult, female whale was found at Agate Beach in Bolinas along the Marin County Coast, about 10 miles north of San Francisco early Friday. She sustained broken ribs, a fractured spine and trauma to her skull, according to the Marine Mammal Center after conducting a necropsy.
The injuries are “indicative of significant blunt force trauma that is consistent with ship strikes,” the scientists said.
A leading cause of whale deaths are ship strikes, the Marine Mammal Center said.
“It is a tragedy that this whale’s story ended due to vessel collision,” Halaska said. “These types of examinations have enabled the scientific community to make recommendations for slower shipping speeds and route changes, and hopefully that will help future whales.”
The whale will be left on the beach to decompose, and eaten by birds and wash back into the ocean.
Because there is a large reef off the beach, which is adjacent to Point Reyes National Seashore, Halaska said, “There’s no way you could get a vessel in there to tow it out.”
“It would be very tricky,” she added.
This was only the ninth time in the 42-year history of the center that it has responded to a blue whale death.
The Marine Mammal Center is a nonprofit veterinary research hospital and educational center that has rescued and treated more than 20,000 marine mammals, according to its website. It is headquartered in Sausalito, Calif.
In 1999, this whale was first identified swimming off the California coast, mostly in and around the Santa Barbara Channel area.
Last October, a 65-foot-long blue whale washed up dead on Westmoor Beach in Daly City, south of San Francisco. The sub-adult male also died as a result of a collision with a ship, scientists found.
Halaska said that some cargo ship operators don’t know when they have hit a whale.
“It might slow down their speed one or two knots, but nothing they would notice,” she said. “These are huge boats. People who have come into port with whales on the bow of their ships have told us they had no idea.”
When whales die in ship strikes, they usually sink to the bottom of the ocean.
On May 1, the Greater Farallones and Cordell Bank national marine sanctuaries asked the operators of large ships to slow their speeds roughly in half to 10 knots — about 11 mph — as they enter the shipping lanes toward the Golden Gate Bridge.
Blue whales are an endangered species, according to the U.S. Fish & Wildlife Service.
Between 8,000 and 9,000 blue whales exist worldwide, including 2,800 blue whales along the California coast, the Marine Mammal Center said.
Blue whales can reach 110 feet in length and weigh 300,000 pounds, the National Oceanic and Atmospheric Administration said.
The average lifespan is 80 to 90 years, the National Geographic said.