General Information

Event name: US-93-009
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 1,900 g STXeq / 100 gr in SSM.)
Associated syndrome: PSP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes
Event occurred before in this location: Yes (1927, '29, '32, '54, '62, '64-66, '70, '71,'76, '80-82, '84, '86-93.)
Individuals to contact: ROSS, Maria R.

Location & Date

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Location: Latitude: , Longitude:
General location information: Marin County., California.
HAB Area code(s): US-21
Additional location information: California areas and shellfish affected. Drakes Bay (SSM, SBM), Drakes Estero (SSM, SBM, WBM, CPO), Keho Beach (WSM), Stinson Beach (WSM), Tomales Bay (SSM, SBM, WBM, CBM, CPO, WC).
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: March- June and October PSP concentration above alert level. In November PSP levels were in the high detectable range below the alert.


Causative organism known: Yes
Causative Species/Genus: Alexandrium catenella ( 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:
In situ
Growth Comments In situ growth. Sea water samples collected March 9 contained an abundance of the dinoflagellate A. catenella but the shellfish collected contained low detectable toxin levels howevr the concentration increased to very high throughout the month of March
Additional Environmental information: No data available.

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: A special quarantine was established on March 12 on all species of mussels taken for human consumption. The annual quarantine on sport harvested mussels goes into effect on May q, 1993 and continues through October 31, 1993. Closure of the growers harvest
Additional harmful effect information: Sentinel sea mussels (SSM) assayed at 1900 g/100 g. meat in March but decreased through June to 320 g and through September to non detectable levels. Again in November the level increased to 220 g. In March the WSM's PSP level elevated to 1300 g, in S