A 79-foot-long blue whale — a member of the largest species on Earth — that washed ashore on Agate Beach in Bolinas was killed in a collision with a ship, according to biologists.

The carcass was found with injuries that indicated blunt force trauma consistent with ship strikes, according to the Marine Mammal Center in the Marin Headlands. The whale’s body had hemorrhaged; 10 ribs were broken in multiple places and the animal suffered a fractured spine, the center reported.

Twenty-five researchers from the Marine Mammal Center and the California Academy of Sciences in San Francisco conducted the animal autopsy, known as a necropsy, on the sub-adult female whale Saturday.

Ship strikes have been a recurring threat to whales around San Francisco Bay and other large ports.

Last October, a 65-foot-long blue whale washed up dead at Westmoor Beach in Daly City. That whale, a sub-adult male, was found to have died from a skull fracture as a result of a collision with a ship, scientists found.

Less than a month ago, on May 1, the Greater Farrallones and Cordell Bank national marine sanctuaries instituted a voluntary policy of asking the operators of large ships to slow their speed to 10 knots — about 11 mph — as they enter the shipping lanes heading toward the Golden Gate Bridge.

Blue whales are not only the largest animals on Earth, but the largest animals ever to have lived. The massive marine mammals can reach 100 feet in length and 300,000 to 400,000 pounds. Their tongues weigh as much as an elephant, and the whales can live 80 years or more.

Blue whales were decimated in the 1800s and 1900s by whaling, a practice that the United States outlawed in 1972. While other whale populations, including those of gray whales and humpbacks, have gradually recovered in numbers, blue whales remain listed as endangered under federal law and have been slower to come back.

Every spring, blue whales swim north from Costa Rica and Mexico up the California, Oregon and Washington coast, following krill, the tiny shrimp-like animals that form the staple of their diets.

On Saturday, national marine sanctuary scientists cruised in boats off the San Francisco and Marin coasts, looking for “hot spots” of blue and humpback whales and radioing ships in the area to warn of their locations.

“Some ship strikes are inevitable, but we may be able to minimize the harm to whales if the ships are moving more slowly,” said Mary Jane Schramm, a spokeswoman for the Greater Farrallones National Marine Sanctuary in San Francisco.

Often when whales die in ship strikes, they sink to the bottom of the ocean. Researchers at the Marine Mammal Center said this whale was found in relatively intact condition, which allowed them to take useful tissue samples to learn more about the animals.

“We rarely have the opportunity to examine blue whales due to their endangered status,” Barbie Halaska, research assistant at the Marine Mammal Center, said in a statement. “The opportunity to perform a necropsy on a carcass in this good of condition will help contribute to our baseline data on the species.”

The beaching in Bolinas was only the ninth time in the 42-year history of the center that it has responded to a blue whale death.

Information from a photo database of blue whales based on their tail markings revealed a match with this weekend’s whale. It was first identified off California in 1999 and seen in at least 11 different years mostly in the Santa Barbara Channel area, according to the Marine Mammal Center.

It is unknown when the whale may have collided with a ship, but it was likely in the past two weeks, said Moe Flannery, ornithology and mammalogy collection manager with the California Academy of Sciences.

Flannery said the whale’s carcass will eventually decompose on the beach. It cannot be buried at the rocky beach, and because of the significance of surrounding reef, it cannot be towed out to sea, she said.

“The body will remain on the beach,” she said. “We’ll see the scavengers in the area, turkey vultures, coyotes, invertebrates in tide pools — and waves will move it around and hopefully take parts out.”

There are some 8,000 to 9,000 blue whales worldwide. Roughly 2,800 blue whales feed along the California coast, according to the Marine Mammal Center. They make up the largest concentration of blue whales in the world.

Bay Area News Group reporters Paul Rogers and Stephanie Weldy contributed to this report.