General Information

Event name: US-96-009
Nature of the harmful event:
Water Discoloration , Mass mortalities
Event directly affected:
Toxicity detected: Yes (Approximate range: 200-260 MU. (Brevetoxin))
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 (Red Tide: Previously occurred in 1986.)
Individuals to contact: STOCKWELL, Dean A.

Location & Date

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Location: Latitude: , Longitude:
General location information: Matagorda Bay to Port Isabel., Texas.
HAB Area code(s): US-18
Additional location information: Red Tide: Coastal texas - Matagorda Bay to Port Isabel (this includes San Antonio, Aransas, Matagorda and Corpus Christi Bays).
Bloom event dates (yyyy/mm/dd): Start: 1996-09-11, End: 1996-10-20
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information:


Causative organism known: Yes
Causative Species/Genus: Gymnodinium breve (300,000,00 cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information:
Event-related bibliography:

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: 27 °C, Min: 21 °C
Salinity Range During Event: Max: 42, Min: 25
Bloom location in the water column:
Growth: Advected
In situ
Growth Comments Initial population advected into nearshore waters, with in situ growth occurring in coastal embayments.
Additional Environmental information: Occurred in nearshore and shelf waters and in coastal embayments and lagoons.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Kit used: Type of kit used:
Additional information:
Economic losses:
Management decision: Red Tide: Shellfish harves bans due to Gymnodinium breve red tide - Matagorda Bay south to Texas-Mexico border. Bays closed from September 1996 - February 1997.
Additional harmful effect information: Red Tide: Dead fish (approximately 5 million) - inshore and offshore within coastal lagoons. Water discoloration brownish-red. Respiratory irritation throughout the entire area. Noted oyster die-offs in areas of high concentrations.
Updated at 03:09 on 14 May 2018