Hundreds of Sharks Wash Up in Foster City, Redwood Shores and Coyote Point

As dead leopard sharks continue to wash ashore around the Bay, the Department of Fish and Game pathologists have identified infection as the cause.

The with the investigation despite budget constraints that have prevented officials from visiting the actual lagoon site. The executive director of the Pelagic Shark Research Foundation, Sean Van Sommeran, has been collaborating with the state department since day one and actively securing specimens to ship to Dr. Mark Okihiro for testing

Of the four sharks sent to Okihiro, the three testable specimens were found to be infected from a carnobacterium or a protozoan, with two showing very clear examples of a damaged nervous system and GI tract.  

“This is really serious,” Van Sommeran said. “Leopard sharks are usually very resistant to infections.”

The first sharks were initially found in the Redwood Shores lagoon by resident Cathy Greer. Since then, she said that many neighbors have been approaching her saying they’ve seen numerous subsequent instances.

Van Sommeran estimates that the count is now up to hundreds of sharks that have washed up from Redwood Shores to Foster City to Coyote Point. He said they could have become infected in the Redwood Shores area, swam to other areas in the Bay then eventually died in those places. Most recently in Redwood Shores, foundation volunteer Brandy Faulkner discovered a shark trapped in the mudflats over the weekend.

Van Sommeran said he was hesitant to specify a cause for infection because the state department had not released an official statement. He said many more specimens needed to be examined. But if the cause is poor water quality, he said, the city could provide a simple solution by installing airaters and other water cleansing mechanisms. He doubted that a chemical spill or any other unnatural isolated incident caused this epidemic of shark deaths.

The city had conducted a water quality test the week after the sightings occurred and reported no abnormalities, according to Public Works superintendent Marilyn Harang. However, Van Sommeran suspected that the lapse in time and fresh water diluting the potential stagnant water might have produced inaccurate results. 

Van Sommeran said he was also concerned because the leopard sharks are the most species that reside close to the shore. He said biologists couldn’t detect what was happening to other species further out in the Bay like seven-gill sharks.

“But we’re continually working on this and the Department of Fish and Game is determined to find the cause of these sharks dying,” Van Sommeran said.