Skip to main content
U.S. flag

An official website of the United States government

Heat wave brings an unprecedented red tide to San Francisco Bay

February 15, 2005

An exceptional red tide in San Francisco Bay was observed on 8 September 2004. The red tide had chlorophyll concentrations approaching 200 mg/m3 (Figure 1) in red/purple surface streaks containing high abundances of the dinoflagellate Akashiwo sanguinea. Red tides and harmful algal blooms (HABs) are common features of coastal ecosystems, and their growing frequency is a suspected outcome of coastal eutrophication.

However, the authors have never observed a dinoflagellate bloom of this scale during 28 years of sampling in the nutrient-rich San Francisco Bay. Phytoplankton biomass along this transect is typically <5mg Chla/m3, and has never exceeded 21 mg Chla/m3 during summer-autumn.

Citation Information

Publication Year 2005
Title Heat wave brings an unprecedented red tide to San Francisco Bay
DOI 10.1029/2005EO070003
Authors James E. Cloern, Tara S. Schraga, Cary B. Lopez
Publication Type Article
Publication Subtype Journal Article
Series Title Eos, Earth and Space Science News
Index ID 70174923
Record Source USGS Publications Warehouse
USGS Organization San Francisco Bay-Delta; Pacific Regional Director's Office

Related Content