More Floridians Made Sick by Toxins Found in Tropical Fish Than Before, New Study Finds

If it's an animal found in Florida, you can be sure it's trying to kill us. With flesh-eating bacteria floating around off our beaches comes more good news from Florida waters — a new study has found that a toxin carried in certain species of edible local fish has been making Floridians sicker than originally thought.

The toxin known as ciguatera cause a series of unfortunate events on our bodies, including vomiting, diarrhea, stomach pain, or cramping. Even more pleasantly, ciguatera can cause aching teeth, muscles, and joints and tingling sensations in your arms and legs. More severe cases also cause painful urination and fever.

According to a study published in the American Journal of Tropical Medicine and Hygiene this week by researchers at the University of Florida's Emerging Pathogens Institute and the Florida Department of Health, cases of ciguatera poisoning in Florida are actually around 5.6 cases per 100,000 people. Though that number seems low in the bigger picture, the original data showed that the previous estimate was .2 cases per 100,000. In other words, the cases are rising.

Ciguatera is found in more than 400 species of fish but more prominently in fish people catch off Florida waters to eat, including barracuda, grouper, and other sport fish. 

According to Florida Health, the toxin is produced by a dinoflagellate algae called Gambierdiscus toxicus — basically algae growing on coral reefs in warm tropical and subtropical ocean waters. Ciguatera is the most common fish toxin there is and is found in higher concentrations within the muscle tissue, organs, and fat of tropical or subtropical predatory reef fish. The toxin is passed up the food chain, from algae to small fish to the big ones people eventually catch and eat.

Now the good news: While it's the most common type of toxin to get from eating tropical fish, experts say the risk of contracting ciguatera poisoning is rare. 

But the reasoning behind the study was mainly to show that there has been an increase and that people need to be aware of the risk. 

The study's author, Elizabeth Radke, PhD, says the findings do suggest that the warnings against eating barracuda are legit. The study did find that grouper, amberjack, hogfish, snapper, mackerel, and mahi-mahi found in Florida have also been found to have ciguatera.

“I don’t think that people necessarily need to stop eating these other fish," she says. "But they need to be aware there is a risk, and if they start feeling sick after eating, they should see a physician.” 

Typically, gastrointestinal symptoms begin within 24 hours for those exposed, followed a day or two later by the other symptoms. 

The best way to avoid the ciguatera toxin, outside of not eating those fish, is to be aware of where the fish were caught. 

"Areas around Miami and in the Florida Keys are particularly affected,” Radke says, according to the study.