Gymnodinium breve Events in 1997-1998

Gymnodinium breve blooms on the southwest coast of Florida normally occur during the late summer-early fall months (Steidinger 1983). In 1997 a short bloom of G. breve was reported beginning August 20, 1997 in the northeastern Gulf near Apalachicola Bay and Cedar Key. Low to very low concentrations of G. breve persisted in the area near Cedar Key through March, 1998. Another occurrence of G. breve began on October 23, 1997 that led to a more wide-spread and persistent event, with G. breve reported at sites south of Tampa Bay throughout the remainder of the year and into 1998. Cell concentrations returned to non-detectable levels by the end of March 1998.

The chart below summarizes the distribution of G. breve occurrences in the Southwest region of Florida through time. Numbers refer to the number of sites sampled.

Bar graph of G. breve Conc.

For more information on harmful algal blooms and their effects, see the NOAA Coastal Services Center Harmful Algal Bloom Project