Skip to main content
U.S. flag

An official website of the United States government

Harmful algal blooms

January 19, 2007

What are Harmful Algal Blooms (HABs)?
Freshwater and marine harmful algal blooms (HABs) can occur anytime water use is impaired due to excessive accumulations of algae. HAB occurrence is affected by a complex set of physical, chemical, biological, hydrological, and meteorological conditions making it difficult to isolate specific causative environmental factors. Potential impairments include reduction in water quality, accumulation of malodorous scums in beach areas, algal production of toxins potent enough to poison both aquatic and terrestrial organisms, and algal production of taste-and-odor compounds that cause unpalatable drinking water and fish. HABs are a global problem, and toxic freshwater and (or) marine algae have been implicated in human and animal illness and death in over 45 countries worldwide and in at least 27 U.S. States (Yoo and others, 1995; Chorus and Bartram, 1999; Huisman and others, 2005).

Publication Year 2007
Title Harmful algal blooms
DOI 10.3133/fs20063147
Authors Jennifer L. Graham
Publication Type Report
Publication Subtype USGS Numbered Series
Series Title Fact Sheet
Series Number 2006-3147
Index ID fs20063147
Record Source USGS Publications Warehouse
USGS Organization Kansas Water Science Center