Fish and Shellfish Toxins

Abstract

Fish- and shellfish-associated toxins are generally derived from toxic microalgae or cyanobacteria growing in the water from which the fishes are harvested with the exception of the scombroid toxin, which is associated with bacterial decarboxylation of fish protein. Six types of algal toxins that are involved in fish and shellfish poisoning include (i) paralytic shellfish poisoning, (ii) diarrhetic shellfish poisoning, (iii) neurotoxic shellfish poisoning, (iv) ciguatera fish poisoning, (v) azaspiracid shellfish poisoning, and (vi) amnesic shellfish poisoning. Scombroid toxin shows allergenic response, while the majority of the algal toxins (Na-channel blocker) affect nerve impulse propagation. Fish and shellfish poisoning are manifested by the diarrhetic, neurological, or anaphylactic response and are prevalent in people living in the coastal areas because of the increased consumption of seafood. Global warming and climate change have been attributed to increased fish-related food poisoning due to increased toxic algal bloom. Toxins are heat-stable; thus, cooking or heating may not be able to inactivate them. To prevent food poisoning, fish and shellfish should be harvested from clean water or purchased from a certified or licensed source before consumption.