Fish-Killing Marine Algal Blooms: Causative Organisms, Ichthyotoxic Mechanisms, Impacts and Mitigation.

Fish-killing microalgal blooms are responsible for much greater global socio-economic impacts than the well-studied HAB species causing seafood biotoxin contamination. Examples are the 1972 Chattonella marina bloom in the Seto Inland Sea, Japan (estimated USD 71M loss to yellowtail aquaculture), the 1988 Prymnesium polylepis bloom in the European Kattegat with broad marine ecosystem impacts, and the 2015/16 Pseudochattonella verruculosa bloom in Chile (USD 800M loss to salmon aquaculture). Highly potent fish-killers include the globally distributed, taxonomically unrelated dinoflagellate genera Alexandrium, Karenia, Karlodinium and Margalefidinium, raphidophytes Chattonella and Heterosigma, dictyochophytes Pseudochattonella and Vicicitus, and haptophytes Chrysochromulina and Prymnesium. All these species have in common their propensity to produce lytic compounds that irreparably damage the sensitive gill tissues of fish which ultimately die from suffocation. Except for recen.....