SAN FRANCISCO (KGO) — There’s an outbreak of a bacterial disease threatening sea lions on the central coast, and it’s starting earlier than usual.

The disease attacks the kidneys of marine animals and is difficult to treat.

The Marine Mammal Center says it used to spike every three to five years. Right now, it’s coming back strong, year-after-year in Santa Cruz and Monterey Counties.

What’s also concerning is that it usually arrives later in the summer.

MORE: Toxic algae bloom killing dolphins, other marine animals along Southern California coast: Experts

“What you’re eating at a local seafood restaurant, in Monterey, is largely the same food California sea lions are eating,” said Giancarlo Rulli with the Marine Mammal Center. “So, when these animals are coming ashore sick, they are that canary in the coal mine. They give us a window into the health of our ocean, and we should be paying attention.”

It’s more severe this year than in past years, with more than 100 sea lions diagnosed just this month.

This disease can spread to dogs and even humans.

Now Streaming 24/7 Click Here

Copyright © 2025 KGO-TV. All Rights Reserved.