As algae blooms increase, scientists seek better ways to predict these toxic tides

The stench of thousands of dead, bloated fish has hung over the beaches of western Florida for months — casualties of an algae bloom that revisits the coastline almost every year. This year’s bloom is particularly intense — and toxic. Called red tides due to the water’s murky reddish tint, the blooms emit a neurotoxin that kills sea creatures, including dolphins and endangered sea turtles, and causes breathing problems for humans.

But the Florida red tide is not the only dangerous algae bloom plaguing water these days. Throughout the United States, a variety of toxic tides are occurring, and they’re happening more frequently, in more places and lasting longer.

On the West Coast, “things have just gotten so much worse” in recent decades, says oceanographer Clarissa Anderson from the Scripps Institution of Oceanography in La Jolla, Calif. Freshwater bodies aren’t immune, either; Lake Erie, for instance, has experienced increasingly large blooms, some even lasting into winter. All of these algae blooms could have negative impacts on human health, animal health and industries like fishing that rely on healthy water ecosystems.