General Information

Event name: US-06-015
Nature of the harmful event:
Water Discoloration , High Phyto concentration , Seafood toxins , Mass mortalities
Event directly affected:
Natural Fish , Shellfish , Humans
Toxicity detected: Yes (Approximate range: Up to 81 mouse units in tests conducted by TX)
Associated syndrome: NSP , Aerosolized toxins effects
Unexplained toxicity: No
Species implicated in toxin transmission (transvector): No reported cases of NSP.
Report the outcome of a monitoring programme: No
Event occurred before in this location: Yes (Texas red tides occur every few years, increasing in frequency.)
Individuals to contact: Byrd, Meridith

Location & Date

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Location: Latitude: , Longitude:
General location information: Texas coast and the Gulf of Mexico, Texas
HAB Area code(s): US-18
Additional location information: Approximately 175 miles of Texas gulf coastline, corpus christi bay (497 sq km), Aransas Bay (70 sq mi), Espiritu Santo Bay (80 sq mi). All three are semi-enclosed estuaries.
Bloom event dates (yyyy/mm/dd): Event Date:2006-10-02
Start: 2006-10-10, End: 2007-02-14
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Bloom began 29 sept 2006 at port aransas, TX. Persisted in the port aransas area while moving up the Texas coast along the gulf and bay sides of San Jose and Matagorda islands and south along the gulf side of Mustang and Padre islands to the jetties at port mansfield. no discolored water or other signs of bloom after late october, though low levels continued to be detected in corpus christi bay through december. Waters remained closed to shellfish harvesting from 1 november 2006 to 14 february 2007.


Causative organism known: Yes
Causative Species/Genus: Karenia brevis (5.0x10^7 cells/L)
This number occurred at Cole Park, Corpus Christi Bay
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Trichodesmium and Karenia mikimotoi were also seen in conjunction with K. brevis.
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: 0
Nutrient information:
Temperature Range During Event: Max: 33 °C, Min: 17 °C
Salinity Range During Event: Max: 38, Min: 22
Bloom location in the water column:
Growth Comments
Additional Environmental information: Bloom began in late summer. Temps and salinity readings were taken very sporadically and may not be the true minimums and maximums. Also, only surface sampling was done so it is not known if a subsurface bloom occurred.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Karenia brevis Brevetoxins 77 mouse units Bioassay-Mouse
Kit used: No Type of kit used:
Additional information: The texas department of state health services conducted mouse bioassays on oyster tissue and used these numbers to close some texas bays to shellfish harvesting from Nov 1, 2005 - feb 12, 2006.
Economic losses: The south padre island convention and visitors bureau compared hotel occupancy numbers from 2004 and 2005 and found that from 9/15/05 to 10/25/05 there were 32 days where occupancy was less than the previous year. Some days the numbers were substantial,
Management decision:
Additional harmful effect information:
Updated at 06:41 on 14 May 2018