General Information

Event name: US-94-016
Nature of the harmful event:
Water Discoloration
Event directly affected:
Toxicity detected: No
Associated syndrome:
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes
Event occurred before in this location: Yes (Brown tide bloom started in December 1989 and has been continously present in Baffin Bay to the present time. Outbreaks have been observed in Mexico and other Texas embayments (Copano Bay, Nueces Bay, Matagorda Bay) for short times in 1991 and 1992.)
Individuals to contact: STOCKWELL, Dean A.

Location & Date

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Location: Latitude: , Longitude:
General location information: , Texas.
HAB Area code(s): US-18
Additional location information: Upper Laguna Madre, Baffin Bay and Lower Laguna Madre, Texas Nueces, Kleberg, Kenedy, Willacy and Cameron Counties.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: All year - seasonal fluctuation in populations with decline in winter, but alwasy dominant organism.


Causative organism known: No
Causative Species/Genus:
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: Chl ranges from 20 g/L to more than 250 g/ µg/l
Additional bloom information: The organism has tentatively been identified as a type III aberrant Chrysophyte sp. RNA seguencing, pigment analysis, and polyclonal antibody assays indicate that the organism is similar to Aureococcus anophagefferens, but there are some differences.
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: °C, Min: °C
Salinity Range During Event: Max: 75, Min: 2
Bloom location in the water column:
In situ
Growth Comments In situ growth. Origin not known.
Additional Environmental information: The organism has been found in bay waters ranging from 2-75 salinity. The most pronounced accumulations have been observed in Baffin Bay, Texas which has very sluggish circulation. The organism thrives on ammonium nitrogen regenerated from sediments and

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Kit used: No Type of kit used:
Additional information:
Economic losses:
Management decision: Shrimp and redfish mariculture hatcheries using alternate water sources where possible. Adjust water intakes to periods of low brown tide standing crop. Grazing studies on zooplankton and larval fish indicate little or no consumption.
Additional harmful effect information: Effects: Water discoloration in all of the above areas. A major concern is the shading and light limitation on seagrass beds in Laguna Madre. There has been a serious disruption of sports fishing for spotted sea trout and redfish. Loss of seagrass beds be