Domoic acid

Domoic acid is a naturally occurring amino acid produced by certain marine algae, responsible for amnesic shellfish poisoning when humans eat filter-feeding molluscan shellfish such as clams, mussels, scallops and oysters that have fed on the algae. It damages neurons, causing gastrointestinal symptoms followed by confusion and memory loss. Because it is heat-stable, cooking gives no protection; safety depends on algal monitoring and closure of harvest areas during blooms. Coastal monitoring programs test shellfish flesh regularly, closing beaches and fisheries when levels exceed safety thresholds.