Can We Prevent Another Algaepocalypse in the Bay?
Starting in July 2022, a dark, reddish-brown tinge crept across San Francisco Bay, leaving dead fish in its wake. Carcasses piled up, first on the shores of Alameda and Lake Merritt, then South Bay, then all the way to Point Pinole. In a matter of weeks, more than 800 sturgeon and countless other fish perished from a lack of oxygen and, possibly, algal toxins.
Last summer’s “algaepocalypse” was the Bay’s worst harmful algae bloom ever recorded. Since then, officials from wildlife, water, and health agencies have been scrambling to piece together what happened—and how future algae blooms might be prevented. Ten months later, they are just starting to get answers.
One human-caused driver has been clear from the start—the sheer amount of nutrients flowing into the Bay that fed the algae, via wastewater, agricultural runoff, fertilizer, and urban runoff. The key elements in this mix are excess nitrogen and phosphorus, which feed algal blooms.
This nutrient pollution problem will be very hard to fix.