Clean-up of mass fish die-off at Oakland’s Lake Merritt underway with hopes to wrap up by Labor Day weekend

OAKLAND — At Lake Merritt, a natural phenomenon has people stopping, staring, and smelling.

“The smell is horrible. The smell is bad,” said Oakland resident Chris Carter. “They’ve got their work cut out trying to find out why these fish are dead like that.”

An algae bloom at Lake Merritt is causing thousands of fish to die. Experts tell KPIX 5 the toxic algae is thriving right now, and when it grows at this rate, it uses up the oxygen in the water, effectively causing the fish to suffocate.

“It’s quite a lot of fish,” said Yabeth Haile, who lives near the lake.

“They need to clean this up immediately,” Carter said. “Don’t go too long with this like this because people will get sick.”

The cleanup process started on Wednesday. The City of Oakland Public Works Department brought in crews to start cleaning up the thousands of fish that have washed up along the shores of the lake.

“The odor is a significant public nuisance out here,” said Sean Maher, a spokesperson for the department. “What we’re seeing is consistent with reported fish die-offs and other wildlife die-offs on shorelines for miles around.”

Maher says they observed the algae several weeks ago, before the bloom.

“In early August, we started observing algae – like a brown and red algae – throughout the lake. This is also consistent with the algae blooms being reported for miles in either direction along the shoreline,” he said. “We’re doing our best to mitigate the impacts, but what’s contributing to it is beyond what’s just here in the lake. We’re seeing this across the Bay shoreline for miles in either direction. We’re working closely with our partners at the California Department of Fish and Wildlife, with the regional water board, to make sure we’re all aligned and taking next steps appropriately.”

He says the city is asking people to stay out of the water, especially kids and pets. However, despite the bloom and subsequent fish die-off, they aren’t cutting off access to the lake at this time.

“Our current condition level remains at caution. Again, we’re not shutting down the lake, we’re not telling people to stay away. We’re just asking people to avoid the water, don’t touch the water or any scum or algae that you may see, and in particular, be careful to keep your children and pets out of it,” he said. “We are not, at this time, telling folks not to boat in the lake.”

Carter says he wouldn’t go out on the water anytime soon.

“I wouldn’t do it. Not until they clean all that out,” he said.

Maher says the hope is to get the situation cleaned up ahead of what will be a busy and hot Labor Day Weekend.

“The Public Works Department is here to clean up the space and provide a comfortable lake for folks to visit,” he said. “We’re working with partners who can study more what the causes here are and help identify and diagnose that.”