Phycotoxins

Harmful algal blooms cause dead zones in water bodies or they may produce phycotoxins that directly or indirectly poison aquatic and terrestrial animals—including humans. Important phycotoxins include saxitoxins, domoic acid, brevetoxins, ciguatoxins, cylindrospermopsins, microcystins, nodularins, anatoxins, guanitoxin, lyngbyatoxins, aplysiatoxins, aetokthonotoxin, and palytoxins. Overfertilization, mismanaged animal or human wastes, burning fuels, reducing plant cover, climate change, dams, and water abstractions concentrate nutrients in water bodies, and shorten generation times of phycotoxin producers. Different phycotoxins cause neurologic, gastrointestinal, hepatic, renal, dermal, and immunologic toxicity, tumor promotion, and/or cancers. Diagnoses of phycotoxicoses are often based on exposure to a source, appropriate signs, clinical pathologic and/or gross and microscopic findings, and analyses of phycotoxins in source materials, digestive tract contents, and tissues. We recommend an updatable repository of information to underpin more effective diagnostics and treatments for poisoned individuals, as well as targeted management actions to remediate and prevent future HABs.