General Information

Event name: US-91-034
Nature of the harmful event:
Seafood toxins , Mass mortalities
Event directly affected:
Birds , Aquatic Mammals
Toxicity detected: Yes (Approximate range: 47 ppm in Monterey County.)
Associated syndrome: ASP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector): Anchovies . This was the first documented case of marine food web effects by this toxin.
Report the outcome of a monitoring programme: Yes
Event occurred before in this location: Yes
Individuals to contact: NORRIS, Tenaya

Location & Date

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Location: Latitude: , Longitude:
General location information: , California.
HAB Area code(s): US-20 US-21
Additional location information:
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: October - December 1991.


Causative organism known: Yes
Causative Species/Genus: Nitzschia pungens f. multiseries ( cells/L)
Few cells were found.
Pseudo-nitzschia australis ( cells/L)
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: 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
Wild sea mussel (Monterey, Nov) Domoic Acid DA eq 47 ppm LC
Razor clam (Humbolt, Dec) Domoic Acid DA eq 29 ppm LC
Kit used: Type of kit used:
Additional information: Analyses by the Fepartment of Health Services Sanitation and Radiation Laboratory (SRL). All Domoic acid data from Sea mussels, unless specified. Domoic acid was found in plankton samples.
Economic losses:
Management decision:
Additional harmful effect information:
Updated at 01:05 on 10 Oct 2020