General Information

Event name: US-11-034
Nature of the harmful event:
Water Discoloration , High Phyto concentration , Seafood toxins , Mass mortalities
Event directly affected:
Natural Fish , Birds , Aquaculture Fish , Other Terrestrial , Shellfish , Humans
Toxicity detected: Yes
Associated syndrome: NSP , Aerosolized toxins effects
Unexplained toxicity:
Species implicated in toxin transmission (transvector): Fish
Report the outcome of a monitoring programme: No
Event occurred before in this location: Yes (Texas has K brevis blooms every few years.)
Individuals to contact: Byrd, Meridith

Location & Date

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Location: Latitude: , Longitude:
General location information: Texas coast, from Port Aransas to Mexico border,
HAB Area code(s): US-18
Additional location information: At one point during the bloom, discolored water and dead fish could be found along over 250 miles of Gulf beach, from San Luis Pass to the Rio Grande, which is the border with Mexico. Major bays/estuaries (with the exception of Sabine Lake) were affected.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd): First detection: 2011-10-05, End: 2012-03-08
Additional date-related information:


Causative organism known: Yes
Causative Species/Genus: Karenia brevis (tens of millions cells/L)
many samples labeled
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: Oxygen content (nL/L): Wind velocity:
Temperature (°C): Oxygen saturation %: Current Direction:
Sechhi disk (m): Salinity: Current Velocity:
Nutrient information:
Temperature Range During Event: Max: °C, Min: °C
Salinity Range During Event:
Bloom location in the water column:
Growth Comments
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Karenia brevis Brevetoxins 23 mouse nits/100 g ELISA
Kit used: Type of kit used:
Additional information: The Texas Dept of State Health Services uses a mouse assay in addition to ELISA kits
Economic losses: The Texas oyster industry was hit hard. All 17,586 acres of oyster beds were closed for half the season (Nov 1-Jan 27). In 2009 the oyster industry brought in $9.4 million over the 6-month season. Coastal communities suffered tourism decline.
Management decision: The Texas Dept of State Health Services delayed the opening of oyster season due to brevetoxin levels. All bays were closed until Jan 27, when 2 bays were opened. DSHS continued to open bays through Feb and early March, when the last bays were opened.
Additional harmful effect information:
Created at 08:08 on 25 Jun 2012
Updated at 06:52 on 14 May 2018