The juvenile female, which was found at Point Reyes on Monday, had blunt force trauma consistent with ship strike.
A necropsy was conducted on the blue whale, the largest animal on Earth, and showed signs of muscle hemorrhage and bone fractures, according to Barbie Halaska from the Marine Mammal Centre. Speaking to NBC Los Angeles, she said that they "had similar injuries" to those seen in ship strike incidents.
The Marine Mammal Centre has reported five blue whales washing ashore since the start of May, with four thought to be victim of ship strike. The San Francisco Bay Area is has heavy shipping traffic which, when combined with significant numbers of large whales, presents a potential risk.
Shawn Johnson, who is the Marine Mammal Centre's Director for Veterinary Science, said that there have alerady been changes to try and address the issue.
Also speaking to NBC Los Angeles, he said: "Giving the ships more options, more shipping lanes coming into San Francisco Bay. There are also recommendations to voluntarily slow down as they get closer."
Johnson went on to say that there had already been a reduction in strikes, but that researchers were still looking at options to reduce the threat further and help protect the various species found on the west coast.
ORCA visited the area last month during our first survey to the Pacific, in partnership with Silversea Cruises, and in fact recorded an adolescent blue whale as a part of our data collection near San Francisco.
We are also expanding our work on ship strike this summer after a successful pilot in 2017 recording fin whale behaviour in the Bay of Biscay to try and understand the issue in more depth, hopefully helping to reduce this issue in the long term.