General Information

Event name: US-03-009
Nature of the harmful event:
Water Discoloration , High Phyto concentration , Seafood toxins , Mass mortalities , Other ( Human respiratory irritation)
Event directly affected:
Natural Fish , Shellfish , Aquatic Mammals , Humans
Toxicity detected: Yes (Approximate range: 22.2 - 145 MU brevetoxin.)
Associated syndrome: NSP , Aerosolized toxins effects
Unexplained toxicity: No
Species implicated in toxin transmission (transvector): Toxic epifauna on leaves of seagrasses which could be transmitted to aquatic animals feeding on seagrass.
Report the outcome of a monitoring programme: Yes (State of Florida Redtide Monitoring Program)
Event occurred before in this location: Yes (almost annually between Pinellas and Lee Counties, 29 of last 30 years.)
Individuals to contact: HEIL, Cynthia A. , TRUBY, Earnest W.

Location & Date

[View larger map]
Location: Latitude: 24.683056, Longitude: -81.189167
General location information: Florida Gulf Coast, Gulf of Mexico.
HAB Area code(s): US-16
Additional location information:
Bloom event dates (yyyy/mm/dd): Start: 2003-01-02, End: 2003-11-20
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Started in 2002 and continued into 2004 in this area. It would decline and then re-establish bloom populations.


Causative organism known: Yes
Causative Species/Genus: Karenia brevis (9,610,000 cells/L)
Co-Ocurring Species/Genus: Karenia sp. (2,230,000 cells/L)
Chlorophyll concentration, if known: 0.401 - 10.33 g/L Chl. 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): Wind velocity:
Temperature (°C): Oxygen saturation %: Current Direction:
Sechhi disk (m): Salinity: Current Velocity: 0
Nutrient information:
Temperature Range During Event: Max: 36 °C, Min: 10 °C
Salinity Range During Event: Max: 40, Min: 17
Bloom location in the water column: Whole column
Growth: Advected
Growth Comments Classically the redtide starts off central Florida.
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Karenia brevis Brevetoxins 46.3 MU Bioassay-Mouse
Kit used: Type of kit used:
Additional information:
Economic losses: Closed shellfish beds, no estimate of loss.
Management decision: followed Biotoxin Control Plan-closed shellfish harvesting areas affected; opened when <20 MU.
Additional harmful effect information:
Updated at 07:25 on 28 Jul 2020