General Information

Event name: US-04-012
Country: UNITED STATES
Nature of the harmful event:
Water Discoloration , High Phyto concentration , Foam/Mucilage in the coast
Event directly affected:
Toxicity detected: No
Associated syndrome:
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: No
Event occurred before in this location: No
Individuals to contact:

Location & Date

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Location: Latitude: 28.000000, Longitude: -89.000000
General location information: Gulf of Mexico,
HAB Area code(s): US-17
Additional location information: Coastal Louisiana, at various times seen from near the Mississippi River plume (28.9651N 89.9988W) to south of Terrebonne Bay (approximately 28.7583N 90.2345W).
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: First samples received 5/3/04, last samples received 5/20/04; The dominant organism found in most of these surface samples was the non-harmful diatom Guinardia delicatatula, along with numerous other centrics, and it is likely that these were the source of the water discoloration; other potentially harmful speces were present during the bloom but caused no harmful effects as far as we know.

Microalgae

Causative organism known: Yes
Causative Species/Genus: Guinardia delicatula (2.5-2.7 x cells/L)
and other non harmful diatoms non enumerated.
Co-Ocurring Species/Genus: Prorocentrum scutellum (76,000 cells/L)
Date Collected: 5/3/04
Prorocentrum gracile (64,000 cells/L)
Date Collected: 5/3/04
Prorocentrum minimum (1,200 cells/L)
Date Collected: 5/3/04
Trichodesmium sp. (1,500,000 cells/L)
Date Collected: 5/5/04
Pseudo-nitzschia spp. (480,000 cells/L)
Date Collected: 5/5/04
Prorocentrum gracile (9,800 cells/L)
Date Collected: 5/5/04
Pseudo-nitzschia spp. (8,100,000 cells/L)
Date Collected: 5/19/04
Prorocentrum gracile (51,000 cells/L)
Date Collected: 5/19/04
Dinophysis caudata (30,000 cells/L)
Date Collected: 5/19/04
Prorocentrum scutellum (18,000 cells/L)
Date Collected: 5/19/04
Pseudo-nitzschia spp. (340,000 cells/L)
Date Collected: 5/20/04
Prorocentrum scutellum (2,133 cells/L)
Date Collected: 5/20/04
Prorocentrum compressum (1,700 cells/L)
Date Collected: 5/20/04
Prorocentrum gracile (1,600 cells/L)
Date Collected: 5/20/04
Prorocentrum minimum (2,400 cells/L)
Date Collected: 5/20/04
Chlorophyll concentration, if known: µg/l
Additional bloom information: This bloom was so persistent and widespread throughout the month of May that state agencies such as Department of Health and Hospitals and Dept. of Wildlife and Fisheries were being contacted by the public concerned about its cause. Complaints were recei
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:
Bloom location in the water column:
Growth:
Growth Comments
Additional Environmental information:

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:
Additional harmful effect information:
IOC/UNESCO ISSHA
IOC/UNESCO ICES PICES