CIGUATERA FISH POISONING - The most common illness associated with fish ingestion in the United States. Human beings contract ciguatera poisoning when they eat large fish (from the tropics) that have fed on dinoflagellates that elaborate neurotoxins. These toxins are concentrated in the fish and are passed on to humans, where they initially cause weakness, nausea, and dizziness, abdominal pain, low blood pressure, and sweating.