Harmful algal blooms on the U.S. west coast

In the U.S, the two major toxic syndromes caused by harmful algal blooms (HABs) that are found along the entire west coast are paralytic shellfish poisoning (PSP) and domoic acid poisoning (DAP), also known as amnesic shellfish poisoning (ASP). Certain species of phytoplankton from the genus Pseudo-nitzschia, and the genus Alexandrium are concentrated by filter-feeding shellfish and finfish which when consumed by humans, marine mammals, or birds can result in ASP and PSP, respectively. Specifically in the subtropical region of Hawaii, ciguatera fish poisoning (CFP) is also known to be a problem, caused a nerve poison, ciguatoxin, produced by the dinoflagellate, Gambierdiscus toxicus. Other harmful species, including the raphidophyte, Heterosigma akashiwo, and the diatoms from the genus Chaetoceros, kill fish at aquaculture sites, but are not known to be harmful to humans. Water discolorations (red tides) caused by noxious phytoplankton, such as Noctiluca scintillans and Ceratium spp., also occur throughout the area and are noted to be nuisance species but are not included in this summary. This report will focus on those algae that produce toxins known to be harmful to humans.