Leopard shark
The leopard sharks are infected by a parasite that goes to their brains.

A shark die-off in San Francisco Bay is being blamed on a parasite in the water. Bay currents are pushing the carcasses ashore at Crown Beach.

So far this year, about 100 leopard sharks have washed up onto beaches around the area, not just in Alameda.

The deaths are blamed on a protozoan parasite that gets into the sharks brains, James C. Frank, Supervising Naturalist for the East Bay Regional Park District told KTVU. If you come across a shark that is struggling, researchers say it is too late to be saved.

This die-off has been happening annually.

In 2017, thousands of sharks were killed by the parasite.

The California Department of Fish and Wildlife is trying to get to the bottom of the problem.