As if rising sea levels, extreme weather and a host of other drastic environmental impacts weren’t enough, scientists are now predicting that global climate change will lead to an increase in ciguatera — a nasty and incurable foodborne illness.

Ciguatera is caused by eating tropical reef fish (such as grouper, snapper and barracuda) that have been contaminated with toxins from marine microalgae. It can result in nausea, vomiting and even some neurologic symptoms, including tingling fingers or toes and a reversed sense of hot and cold temperatures.

In a new study published in the journal Ecological Modeling, researchers with the National Oceanic and Atmospheric Administration found that expected increases in ocean temperatures in the Gulf of Mexico and the Caribbean through 2099 will likely lead to far more abundant and more diverse neurotoxins associated with ciguatera fish poisoning.

Red snapper, Lutjanus bohar, eating a Diadema sea urchin on the fore reef of Kingman Reef, 10 m depth. The red snapper is the second most abundant predator at Kingman Reef, second only to sharks. They are voracious predators that eat everything from fishes to giant clams to sea urchins.
A red snapper eats a sea urchin on the fore reef of Kingman Reef, 930 miles south of Honolulu. Enric Sala

The forecast is part of a larger effort to develop and implement strategies for managing the risk of the illness, NOAA said in a release.

“Contaminated fish have no specific taste, color, or smell and there is no easy method for measuring ciguatoxins,” said Steve Kibler, a NOAA scientist and the study’s lead author, in the release. “However, we can forecast risk based on where and when we are likely to find the algae that produce ciguatoxins.”

More than 400 fish species are known to become contaminated, according to NOAA. In U.S. waters, ciguatera occurs in Hawaii, Guam, southern Florida, Puerto Rico, the U.S. Virgin Islands and occasionally in the Gulf of Mexico.

Earlier this year, a study found that ciguatera poisonings in Florida were an estimated 28 times more common than previously thought.

An estimated 10,000 to 50,000 people suffer from the illness each year, making it the most commonly reported marine toxin disease in the world. However, those are likely just the tip of the iceberg, as only an estimated 2 to 10 percent of all cases are actually reported to health authorities.

While ciguatera’s symptoms can be treated, the illness itself has no cure. And anecdotal reports indicate that some patients experience recurring neurologic symptoms upon consuming alcohol, fish and other foods, even years after the initial exposure.

“Whatever I touched, if it was hot, it would feel cold. If it was cold, it felt hot,” one patient recalled. “I couldn’t walk on the tile floor. It felt like it was burning me.”

If global sea level rise wasn’t enough to convince you it’s time to reduce your carbon footprint, maybe your appetite for fish will.

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