By Name

IOC UNESCO Taxonomic Reference List

This comprehensive list of harmful micro algae prepared by the IOC Harmful Algal Programme may also be of interest:

Please refer to the EPA's CyanoHAB website for information on freshwater taxa:

Causative Organism Toxin/Bioactive Compound Human Health Effects and/or Syndrome Impacts to wildlife and/or domestic animals Ecosystem Disruption Impacts Economic Impacts Impacted Areas in U.S.
Akashiwo sanguineum Surfactants Suspected respiratory irritant Migratory bird deaths, including protected species Water discoloration; Foam formation Rehabilitation of protected bird species Pacific Coast
Alexandrium monilatum
Goniodomin Fish and shellfish mortality Water discoloration Gulf of Mexico and Atlantic coast up to New Jersey
Alexandrium*; Gymnodinium*; Pyrodinium bahamense Saxitoxins Respiratory paralysis, death (Paralytic Shellfish Poisoning or PSP) Marine mammal deaths Loss of shellfish harvesting income; human illness from recreational harvest; closure recreational puffer fish harvest in FL Pacific coast, including Alaska; NE Atlantic coast;
Aureococcus anophagefferens --Long Island Brown Tide Not characterized Water discoloration; seagrass and shellfish die-offs; hypoxic zones Loss of shellfish harvesting income; interference with restoration Mid-Atlantic coast
Aureoumbra lagunensis --Texas Brown Tide

Not characterized: extracellular polymeric substance (EPS); possibly other uncharacterized compounds

Water discoloration; Loss of submerged aquatic vegetation Texas, Florida
Reactive oxygen species (ROS); possibly other uncharacterized compounds Fish kills Water discoloration Severe impacts on fish and shellfish maricultrue in Asia West Coast, Mid-Atlantic
Dinophysis; Prorocentrum* Okadaic acid; Dinophysotoxins Gastrointestinal distress (Diarrhetic Shellfish Poisoning or DSP) Closing of shellfish fisheries Oregon, Texas, Washington, Long Island Sound; Cape Cod, MA
Gambierdiscus* Ciguatoxins Sensory and gastrointestin al dysfunction (Ciguatera Fish Poisoning or CFP) Unknown; Possible impacts to monk seals Bans on fish sales from affected areas, cost of medical treatment, loss of protein source Florida, Gulf Coast, Hawaii, Pacific, and Caribbean
Heterosigma akashiwo Ichthyotoxins Fish kills Water discoloration Loss of fish net pen mariculture Washington; Mid-Atlantic coast
Karenia Brevetoxins Neurotoxicity; Gastrointestinal and sensory effects (Neurotoxic Shellfish Poisoning or NSP), respiratory effects Fish kills; manatee, dolphin, marine turtle, and bird deaths Water discoloration Loss of tourism income; Removal of dead fish from beaches, shellfisheries closing, increased emergency room visits due to respiratory and gastrointestinal illness, wildlife rehabilitation Gulf of Mexico and Atlantic coast up to Delaware
Karlodinium Karlotoxins Fish kills Water discoloration Atlantic and Gulf Coasts
Macroalgae H2S, dopamine Respiratory impacts Impair nesting protected species Shade submerged aquatic vegetation, overgrow coral reefs, cause hypoxia Removal from beaches; loss of tourism income All coasts
Marine cyanobacteria (formerly Lyngbya) Dermatotoxins Impact divers on coral reefs Overgrow coral reefs Loss of tourism income South Florida
Other Raphidophytes: Chattonella, Fibrocapsa Ichthyotoxins; Brevetoxins
Fish kills
Water discoloration Mid-Atlantic coast
Prorocentrum minimum--Mahogany Tides Not characterized Mortality of spat in shellfish hatcheries Water discoloration Loss to shellfish hatcheries Chesapeake Bay
Pseudo-nitzschia Domoic Acid Gastrointestinal and central nervous system effects (Amnesic Shellfish Poisoning or ASP) Sea bird and marine mammal mortality Closure of shellfish harvesting, loss of tourism income, wildlife rehabilitation West Coast, Florida, Maine
*only some species within the genus produce toxins

Last updated: July 28, 2016