Bay fishers still reeling from summer’s red tide, which could make a fall return

As dozens of dead fish pile along the shoreline, rotting under the baking sun, the stench is a minor inconvenience to the local anglers who are struggling with the financial burdens brought on by the recent algae bloom.

In late July, the San Francisco Bay Area witnessed the largest Heterosigma akashiwo bloom in recorded history. Notoriously dubbed the red tide, this environmental tragedy resulted in a mass fish kill that ravaged the marine life in the bay, decimating over tens of thousands of different species.

“It’s back to normal right now, but the damage has already been done,” said Steven Mitchell, a charter fisher operating out of the Pittsburgh and Berkeley marinas.

Although the red tide has nearly cleared, the threat remains for another one, and the economic impact of this summer’s event is still being felt by local fishers. The livelihood of each fisher is dependent on the health of the marine ecosystem, and human interference stands as the root cause of their economic downturn.

At the height of the red tide in early August, fishing in Richmond came to a standstill. The bloom killed thousands of fish while also driving those who were able to survive further out into the ocean.

For at least two weeks, the bites were gone.

Andy Guiliano, owner of Fish Emeryville and captain of the charter boat Play’n Hooky, witnessed a variety of fish floating on the surface of the water during his excursions on the bay. 

“That was pretty unusual,” he said. “We generally don’t see any fish that are floating that are dead.”

Guiliano said the red tide was heavier and more prevalent in certain waters where he found the algae to extend down to the sea floor. 

“Heavy concentrations seemed to be in areas that receive less tidal flow — Richmond, Inner Harbor, Lake Merritt, where the water tends to be more stagnant,” he said. 

As a result, it became increasingly difficult to acquire bait due to the mass fish kill brought on by the bloom. 

“We’ve got bait receivers behind our boats and we keep live bait,” with water circulating through the receiver, said Mitchell. “All of our bait was dead. We couldn’t keep nothing in it.”

The sight of a mass fish kill, the scarcity of bait and the financial burden of the red tide left fishers looking for answers.

Together, the San Francisco Bay Regional Water Quality Control Board in Oakland and the San Francisco Estuary Institute in Richmond monitor the bay’s water quality. They found the algae bloom to be a result of the extended drought, climate change and less runoff in the nutrient enriched estuary. The decline of sediment levels in the bay made the water less turbid and allowed sunlight to penetrate through the surface.

“We think some combination of those factors caused this algae bloom, and then the high nutrient load allowed it to grow and expand in the bay,” said Eileen White, executive officer for the Water Board SF Bay Region.

White said the 37 sewage plants that discharge effluent into the bay are responsible for over 60% of the nutrients found in the aquatic ecosystem. Though the wastewater is treated to meet regulation standards, there is no limit on nutrient levels, she added.

“If we continue to have dry, warm weather with not much wind, we can have even another algae bloom potentially in October,” White said.

With the threat of another major red tide looming, the future of the fisheries is uncertain. The health of the waterways remains in question as fishers grapple with pollutants in the bay.

“I just hope that everything sustains and we’ll be able to just keep our fishery going not only for me but for my grandkids and their grandkids to do the same thing that I’m doing right now, versus it being destroyed,” Mitchell said.