The third dead whale in a week has washed up in the San Francisco Bay Area. The two earlier whales died of a ship strike and fishing-gear entanglement, while experts are still working to determine the cause of the latest death.
“The deaths of these two whales highlights the direct negative impact humans can have on marine wildlife,” Dr. Shawn Johnson of the Marine Mammal Center in Sausalito said in a statement after first causes of death were determined.
Three gray whales were also found dead in the area from March to early May.
The latest death was a 58-foot fin whale that washed up near Agate Beach in Bolinas in Marin County on Wednesday. The Marine Mammal Center and the California Academy of Sciences were on the scene after the discovery, and plan to conduct a necropsy Friday to determine the cause of death. Fin whales are an endangered species.
A 45-foot female juvenile fin whale washed up last Friday near Jack London Square in Oakland. It had suffered massive hemorrhaging on both sides of its body and fractures in a collision with a ship in the bay, officials said. It was spotted Wednesday draped over the bow of a large ship entering the bay.
Last Friday, a 36-foot adult female gray whale was also found dead at Tennessee Valley Beach in Marin County. Scientists found linear lesions around the neck and both front flippers, consistent with entanglement, which was the cause of death. The whale also had several lacerations and multiple skull fractures from a ship propeller, but those likely occurred after death, according to the center.
The earlier deaths of three gray whales were due to a ship strike, malnutrition and net entanglement.
Ship strikes and entanglement in fishing gear are leading causes of death for whales. Strandings and deaths increase in the spring while the animals are migrating from Mexico to Alaska up the California coast.
It’s not clear why there were three whale deaths in such a short span of time. The Marine Mammal Center uses information it gleans to provide greater protections in the future. In 2013, changes were made to the mile-wide shipping lanes into San Francisco Bay to reduce the risk for whales.