General Information

Event name: US-03-005
Nature of the harmful event:
Seafood toxins , Other ( High densities of Pseudo-nitzschia observed by volunteer network)
Event directly affected:
Toxicity detected: Yes (Approximate range: 1 - 80 ppm DA.)
Associated syndrome: ASP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (California Department of Health Services' Marine Biotoxin Monitoring Program)
Event occurred before in this location: Yes
Individuals to contact: LANGLOIS, Gregg

Location & Date

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Location: Latitude: , Longitude:
General location information: Santa Cruz and Monterey Counties., California, Northern California.
HAB Area code(s): US-20
Additional location information:
Bloom event dates (yyyy/mm/dd): Start: 2003-05-13, End: 2003-05-21
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: NORTHERN CALIFORNIA (progressing north to south): Santa Cruz and Monterey Counties: High densities of Pseudo-nitzschia and elevated domoic acid concentrations from February through early April; elevated levels reoccurred in September and October in sardine fished from Monterey Bay. Peak concentrations observed late March/early April (68-80 ppm in mussels). Pseudo-nitzschia bloom also occurred in Del Norte, Humboldt and Marin counties. Low levels of domoic acid detected in mussels from Humboldt in mid August and in crab viscera from Sonoma in late October. Higher levels of domoic acid were detrected in crab viscera from Marin County in late October (41 ppm).


Causative organism known: Yes
Causative Species/Genus: Pseudo-nitzschia spp. ( cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Additional species: Numerous dinoflagellate and diatom species.
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 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: