Distribution of HABs in the U.S.

Coastal waters of the United States are subject to most of the major HAB poisoning syndromes and impacts. These include paralytic shellfish poisoning (PSP), neurotoxic shellfish poisoning (NSP), amnesic shellfish poisoning (ASP), ciguatera fish poisoning (CFP), brown tides (BT), cyanoHABs and a number of other HAB phenomena such as fish kills, loss of submerged vegetation, shellfish mortalities, and widespread marine mammal mortalities. 


Approximate areas of the U.S. coast affected by various HAB poisoning syndromes and other impacts. Note that cyanoHAB dots and golden alga dots portray geographically general representations of outbreaks and may represent events occurring in more than one water body within a state.  Note also that not all HABs are depicted in this generalized view of the U.S.


U.S. maps
The following maps depict the frequency of specific HAB problems along the U.S. coast over the last ten years. These data are updated annually to generate a time series of the events.

ASPAmnesic Shellfish Poisoning


CFPCiguatera Fish Poisoning


Diarrhetic Shellfish Poisoning


NSPNeurotoxic Shellfish Poisoning


PSPParalytic Shellfish Poisoning


Plant and Animal Mortalities




Last updated: July 31, 2012