Scientists Ponder Why Fish Are Spinning Themselves to Death

Next of Spin

The mystery surrounding the disturbing phenomenon of fish spinning themselves to death in Florida is as murky as the ocean's depths, but scientists may have a lead: poisonous algae.

While red tide algae hasn't been detected where the fish are dying, scientists working with the state Fish and Wildlife Conservation Commission (FWC) tested water samples and discovered they contained other "harmful algal species" while "associated toxins" have also been found in fish tissues, according to a FWC statement.

But more testing is needed to further pinpoint the cause of this condition, according to FWC, which has impacted a variety of fish.

Finding the cause is especially pressing because fish anglers, ocean divers, and wildlife officials have seen the spinning behavior in sawtooth fish, an endangered species, before they die.

As of May 8, FWC has also recorded an alarming spike in deaths for the sawtooth fish with 47 dead — and they think the spinning and increase in mortality are related.

Murky Waters

Poisonous algae that produces toxins, which includes the infamous red tide, have been around since before humans walked on the Earth. But warming waters from climate change, increased development, and agricultural runoff are a toxic brew that's making them more frequent, scientists told Newsweek last year in March amidst a bad red tide bloom.

Over the last half century, red tide blooms have increased 15-fold, University of Miami's professor of marine biology and ecology Larry Brand told Newsweek last year.

"Being an algae, it needs nitrogen and phosphorus to grow," he was quoted as saying. "I attribute [the 15-fold increase] to the large increase in human activities in South Florida over the past 50 years, primarily fertilizer and sewage runoff. It is not clear if higher temperatures from climate change are increasing red tide, but the more intense rainstorms associated with it will be leading to more nutrient runoff."

Fish kills, whether they are caused by red tide or another algae, are a terrible problem not just for the health of the fish and oceans but also their impact on humans.

People who eat fish infected by red tide can come down with food poisoning that's life threatening. And breathing in the red tide can cause breathing problems as well.

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