By the time a barracuda, snapper, or grouper is caught, it potentially has accumulated high levels of ciguatoxins.

Toxin-producing Gambierdiscus phytoplankton attach to seaweed, sand, and dead corals.

Carnivorous fish eat smaller ones, and the ciguatoxins move up the food chain.

Fish that eat seaweed or scrape dead coral coincidentally consume Gambierdiscus.

Ciguatoxins continue to accumulate in fish at the top of the food chain.

Ciguatera Fish Poisoning causes severe gastrointestinal and neurological symptoms in people. It is caused by toxins made by phytoplankton.

The Gambierdiscus toxins are biotransformed by fish into ciguatoxins.