The bloom was detected in late July in the Oakland and Alameda areas, and dead fish have since washed ashore in the bay as well as at Oakland’s Lake Merritt, California fish and wildlife department spokesperson Jordan Traverso said.
“It’s estimated that 10,000 yellowfin gobies died … as well as hundreds of striped bass and hundreds of sturgeon,” and the bloom probably is impacting all aquatic species in the area “to some degree,” Traverso said.
Algae blooms and dead fish were reported not only along the Oakland and Lake Merritt shorelines, but also “for many miles to the north and south along the coastline,” Oakland’s release reads.
Precisely what killed the fish was not immediately known, but it’s “likely related to dissolved oxygen levels and/or toxins produced by the algal bloom,” Traverso said.
The cause of the bloom was also not clear. Oakland’s government cited several potential sources and contributing conditions.
“Current research suggests that the rising temperatures and changing precipitation patterns caused by climate change are a catalyst for their growth,” the post continued.
The state fish and wildlife department is working to sample strategic locations to “verify the extent of the harm to fish and aquatic species,” Traverso said.
Oakland’s public works department and its water board detected “low levels of contaminants associated with harmful algae blooms” in May, the city said. The city then posted signs warning lake visitors that harmful algae might be there, and not to touch the water, it said.