Study of Ciguatera Poisoning in the Virgin Islands

Earlier this month at the University of the Virgin Islands, scientists researching ciguatera fish poisoning in the U.S. Virgin Islands discussed some of their preliminary findings from a three-year study of ciguatera that was just launched last December. Here are excerpts with a link to the full article below:

The project’s purpose is to study how ciguatera works its way up the food chain, how it affects human health and if climate change or environmental factors contribute to higher or lower instances of the poisoned fish. Ciguatera poisoning is caused by naturally occurring toxins, called ciguatoxins, which are produced by microscopic plants – gambierdiscus toxicus – that live on seaweed and other surfaces within coral reef communities. When fish eat seaweed or algae they consume the organisms, too, and the ciguatoxins build up in the fish’s flesh. The toxin is fat soluble – it is stored in the fishes’ body and not excreted – so it builds up as it goes up the food chain. The bigger fish eat the little fish and the toxin gets passed on until it is consumed by humans. Predators at the top of the food chain – like barracuda – can end up with large amounts of the toxin in their flesh. No test can be done to determine if the fish is poisoned and cooking and preparation methods have no effect on the toxin.

[. . .] UVI coral reef researcher Tyler Smith and students at UVI’s Center for Marine and Environmental Studies have spent the last year collecting samples of plants, algae and fish at four sites on a monthly basis and sending them to the project’s investigators for analysis. The four sites identified [are] Black Point, Flat Cay, Benner Bay, and Seahorse. Smith found a link between the abundance of microscopic plants which produce ciguatoxins and the seasonal fluctuations in water temperature, although he said more study must be done.

[. . .] The microscopic plant cells secrete mucus, which they use to attach to algae and other surfaces, but Smith said they cannot attach to live coral. Woods Hole Oceanographic Institution research associate Mindy Richlen, the co-principal investigator for the project, said she has hypothesized that events which cause massive coral death – like coral bleaching due to warmer water temperatures or dredging projects – may lead to more cases of ciguatera. She said when there is less live coral, there are more surfaces available for the ciguatoxin producing plants to attach to, which could mean an increase in the amount of toxins consumed by reef fish and ultimately the amount of toxic fish consumed by humans.

[. . .] Patterns in the Ciguatera Fish Poisoning Monitoring project include the Emerging Pathogens Institute at the University of Florida, UVI, University of Maryland School of Medicine, Woods Hole Oceanographic Institution, Schneider Hospital, the Food and Drug Administration Dauphin Island Lab and Florida State University. The project is funded through a $1 million grant from the Centers for Disease Control and Prevention.

[. . .] Symptoms of ciguatera fish poisoning can appear within hours to a few days after eating infected fish. Treatments are available and the symptoms may pass within a few days to six months. Symptoms can include nausea or vomiting, diarrhea, electric shock-like or painful sensations, reversal of hot and cold sensations, intense itching or tingling fingers and toes, slowed heart rate and a drop in blood pressure, weakness or fatigue, muscle or joint pain, depression, and headaches.

For full article, see

For more information on the ciguatera research project, see

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