Forecasting harmful algal blooms in the Bay Area

Harmful algal blooms should, in theory, have struck the San Francisco Bay Area far more often over the past few decades. Yet the region, home to 7.5 million people, has experienced relatively few events compared to other nutrient-rich estuaries. Scientists have attributed this anomaly to invasive algae-eating clams and high levels of tidal and wind-driven mixing in the bay, which limits the exposure of plankton to the sun they need to grow. That all may have changed last fall, when a massive bloom that tinted the bay red for a month depleted dissolved oxygen and killed fish. Prolonged periods of dry weather and heavy nutrient loads will likely give rise to more “red tides” in the future, yet resource managers lack tools to inform prevention and response. Oliver Fringer, professor of civil and environmental engineering and of oceans, will partner with the San Francisco Estuary Institute to create a system for predicting future harmful algal blooms. Using a machine learning algorithm, they will combine historical data sets from numerical models, field measurements, and satellites to assess the likelihood of blooms in different regions of the bay and at desired times.