‘Uncountable’ Number of Fish Killed in San Francisco Bay Due to Deadly Red Tides

by Shelby Scott

Last year, Florida’s summertime red tide killed a massive amount of sealife, resulting in the deaths of 600 tons of various wildlife. Now, a year later, California is enduring a deadly red tied of its own, leaving an “uncountable” number of fish dead in San Francisco Bay.

According to Field & Stream, San Francisco’s red tide, caused by a toxic algae bloom known as Heterosigma akashiwo and resulting in what we know as red tides, has left tens of thousands of fish dead. The tides are not deadly to humans, but they are absolutely fatal to various sea life. In addition, the outlet reports that though red tides are always present in the San Francisco Bay, the area hasn’t experienced one this severe since 2004.

Addressing the current bloom in a press release, San Francisco Baykeeper places blame on humans. The Baykeeper wrote, “Treated sewage discharges from the Bay’s 40 sewage treatment plants and the pollutants from five dirty oil refineries create conditions ideal for algal blooms.”

Calling for better management on the part of the oil refineries and sewage treatment plants, the statement continued, “Baykeeper scientists have been actively working for the past five years through agency technical advisory committees to prevent large blooms of any number of potentially toxic microorganisms from becoming commonplace in the Bay.”

The press release specifically called on the Regional Water Board to help contain this issue in the San Francisco Bay by getting “excessive sewage and refinery discharges under control.” Calling out city officials, they added, “Bay Area cities need to invest in water recycling to keep wastewater out of the Bay in the first place.”

They conclusively said, “Hopefully this is a wakeup call.”

San Francisco Bay’s Algal Bloom From a Fish’s Perspective

The current red tide suffocating many of San Francisco Bay’s fish is, compared to other natural occurrences somewhat foreign to humans. Because they don’t physically affect us, it’s hard to truly comprehend what an algal bloom does to a fish, dolphin, shark, etc. Fortunately, amid the current crisis, Jon Rosenfeld, senior scientist with the San Francisco Baykeeper provided a little bit of perspective.

“From a fish’s point of view,” he explained, “this is a wildfire in the water.” In speaking about the physical effects on the sea life compared to what we can physically see, he added, “What you see is just a hint of what’s actually happening further beneath the surface and in places you’re not getting to on the shoreline. So [the total fish kill is] really an uncountable number.”

Field & Stream reports that scientists have been tracking the current red tide and its fatal effects since July. And though they expect it to come to an end in the coming weeks as the days get shorter, it doesn’t appear to be dissipating any time soon. And as such, officials are concerned with how the rapidly depleted local fish supply will affect San Francisco Bay’s recreational and commercial fisheries.