Bay Area dead fish smell blamed on toxic red tide

OAKLAND, Calif. — An unprecedented red tide in the San Francisco Bay Area is killing thousands of fish and other marine life whose carcasses are washing ashore, creating a foul odor that experts say could get worse during this weekend’s expected heat wave.

At Oakland’s Lake Merritt, a popular spot for joggers, walkers and those looking to be in nature, crews on Wednesday began removing dead crabs, bat rays, striped bass and other fish that began piling up on its rocky shores over the weekend.

The fish die-off throughout the Bay Area may be due to a harmful algae bloom that has been spreading in the region since late July, said Eileen White, executive officer of San Francisco Bay Regional Water Quality Control Board.

“We normally have algae blooms during the summertime. But what’s unusual about this one is how large it is and the fact that there are fish kills,” White said.

Most algae blooms end after a week or so. But a triple-digit heat wave forecast for the holiday weekend may help the Bay Area’s grow even more, White said. Reports of dead fish started coming in last week.

“This was a natural occurrence of Mother Nature and so, we don’t know when it’s going to end,” she said

Scientists say a yearslong drought has prevented stagnant water from flowing into the ocean and unseasonably warm and sunny weather may be helping the algae spread.

Jon Rosenfield, a scientist with the San Francisco Baykeeper conservation group, said high levels of nutrients such as phosphorus and nitrogen in wastewater also drive the growth of algae blooms.

“The only lever that we have to control the problem is to reduce nutrients put into the bay from the 40 wastewater treatment plants that operate around the bay,” he said.