Ciguatera is a toxin passed from smaller fish to larger fish and then if the fish is consumed by humans the toxin is then stored in the body. When it reaches a certain level the effects can cause the person to become extremely ill. It can occur in reef fish, finfish, and shellfish as well. Read up about it and be sure to talk with the locals before fishing in and around islands to find out if Ciguatera is a problem there.
Care should also be taken trolling a line between islands and consuming fish caught. To be on the safe side, avoid eating any fish that are caught around island shores.
The most important fact is that your body never purges the toxin. It’s stored in your body and then eating a fish years later having a small amount of toxin can trigger a reaction again.
Ciguatera fish poisoning: Treatment, prevention and management
Ciguatera – how do you tell if a fish has it?