These are some of the organisms responsible for harmful algae blooms in U.S. coastal waters:

  • Gymnodinium breve, a dinoflagellate, produces neurotoxic shellfish poisoning along the coasts of the Gulf of Mexico and, rarely, the southeast Atlantic Coast.
  • Various species of the dinoflagellate genus Alexandrium are responsible for paralytic shellfish poisoning in New England, Northern California, the Pacific Northwest and Alaska.
  • Aureococcus anaphagefferens, a small, golden brown algae, is responsible for brown tide bloom in southern New England, particularly Long Island, and in New York and Texas. Aureoumbra lagunensis, a similar species, causes blooms in Texas bays and lagoons.
  • Blooms of various species of the diatom genus Pseudo-nitzschia produce domoic acid that causes amnesiac shellfish poisoning on the Northwest, East and Gulf Coasts.
  • The raphidophyte flagellate Heterosigma akashiwo and a few species of the diatom genus Chaetoceros cause catastrophic losses of cultured and wild fish, particularly in the Pacific Northwest.

Sources: Maryland Sea Grand and "Harmful Algal Blooms in Coastal Waters" produced by the National Oceanic and Atmospheric Administration's Coastal Ocean Program