General Information

Event name: US-12-021
Nature of the harmful event:
Water Discoloration , High Phyto concentration , Seafood toxins , Mass mortalities
Event directly affected:
Natural Fish , Birds , Shellfish , Aquatic Mammals
Toxicity detected: Yes (Approximate range: 22.2 - 37.7 g / 100 g shellfish)
Associated syndrome: NSP , Aerosolized toxins effects
Unexplained toxicity:
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (FWC/FWRI HAB Monitoring Program)
Event occurred before in this location: Yes (Historically, Karenia brevis blooms occur in SW Florida shelf almost annually usually beginning in summer or fall.)
Individuals to contact: SCOTT, Paula

Location & Date

[View larger map]
Location: Latitude: , Longitude: -83.471667
General location information: SW Florida, 4
HAB Area code(s): US-16
Additional location information: Gulf of Mexico: 230 miles n to s; 72 miles w to e (patchy movement alongshore throughout the fall, mostly lingering around Lee & Collier counties
Bloom event dates (yyyy/mm/dd): Event Date:2012-09-17
Start: 2012-09-17, End: 2013-05-01
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: 2011 bloom continued through 03/12/2012


Causative organism known: Yes
Causative Species/Genus: Karenia brevis (8,800,000 cells/L)
Co-Ocurring Species/Genus: Skeletonema spp. (26,129,300 cells/L)
Chlorophyll concentration, if known: µg/l
Additional bloom information:
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): 6.1 (mg/L) Wind velocity:
Temperature (°C): 27.1 Oxygen saturation %: Current Direction:
Sechhi disk (m): Salinity: 35.73 Current Velocity:
Nutrient information:
Temperature Range During Event: Max: 30.5 °C, Min: 18 °C
Salinity Range During Event: Max: 40.0, Min: 22.3
Bloom location in the water column: Whole column
Growth: Advected
In situ
Growth Comments
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
clams Brevetoxins 37.7 MU/100 g Bioassay-Mouse
Kit used: No Type of kit used:
Additional information: manatee tissues as assayed by ELISA for PbTx
Economic losses: unknown
Management decision: shellfish harvesting closures until Karenia brevis cell counts fell below 5,000 cells/L and shellfish NSP toxins below 20 MU/100 g.
Additional harmful effect information: Reports of respiratory irritation throughout affected bloom areas
Created at 08:37 on 7 Apr 2014
Updated at 08:13 on 29 Jul 2020