General Information

Event name: US-96-004
Nature of the harmful event:
Water Discoloration , Seafood toxins , Mass mortalities
Event directly affected:
Birds , Other Terrestrial , Aquatic Mammals , Humans
Toxicity detected: Yes
Associated syndrome: NSP , Aerosolized toxins effects
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes
Event occurred before in this location: Yes (Usually patchy along Florida coast, not necessarily coast wide. Jan-Dec 1995, Sept-Dec 1994, Jan 1993 (cont. Of Dec 1992) Sept-Dec 1992, Jan-Feb 1991, Feb-Mar, Oct-Nov 1990; Mar-May 1989; Oct-Dec 1988; Jan-Feb, May -July, Sept-Oct 1987; Sept-Dec 1986; Sept-Dec 1985; Jan-Mar, May-Aug 1984; Jan-Feb, Oct-Dec 1983; Jan-Apr, July-Oct 1982; Sept-Oct)
Individuals to contact: STEIDINGER, Karen A.

Location & Date

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Location: Latitude: , Longitude:
General location information: Pensacola to the Florida Keys., Florida.
HAB Area code(s): US-16
Additional location information:
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: January - June, October and November 1996 (inshore, offshore), September - December 1996 (offshore central west coast) and continued into 1997 as an offshore bloom.


Causative organism known: Yes
Causative Species/Genus: Gymnodinium breve (0 - 10,000 cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Inshore and coastal water samples up to 45 miles offshore.
Event-related bibliography: Foley, A., Stacy, B. A., Schueller, P., Flewelling, L. J., Schroeder, B., Minch, K., Fauquier, D. A., Foote, J. J., Manire, C., Atwood, K. E., Granholm, A. A., Landsberg, J. H., 2019. Assessing Karenia brevis red tide as a mortality factor of sea turtles in Florida. Dis. Aquat. Org. 132, 109124.

Environmental Conditions

Weather: Turbidity (NTU): Wind direction:
Stratified water: No Oxygen content (nL/L): Wind velocity:
Temperature (°C): Oxygen saturation %: Current Direction:
Sechhi disk (m): Salinity: Current Velocity: 0
Nutrient information:
Temperature Range During Event: Max: 32 °C, Min: 12 °C
Salinity Range During Event: Max: 36, Min: 15
Bloom location in the water column:
Growth: Advected
Growth Comments Advected population from offshore waters between Tampa Bay and Charlotte Harbor. In February, warm water intrusion documented off southwest Florida which preceeded establishment of red tide in Pine Island sound. In November, Loop Current water documented
Additional Environmental information: Occurred in nearshore and shelf waters with wide salinity and temperature range.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Brevetoxins Bioassay-Mouse
Kit used: Type of kit used:
Additional information:
Economic losses:
Management decision: Shellfish harvest bans due to Gymnodinium breve red tide in most major shellfish harvesting areas along the west and north coasts of Florida at some point in year.
Additional harmful effect information:
Updated at 06:33 on 28 Jul 2020