General Information

Event name: US-94-017
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 930 g STXeq / 100 g tissue.)
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, 1929, 1932, 1954, 1962, 1963, 1964, 1965, 1966, 1970, 1971, 1976, 1980, 1981, 1982, 1984, 1986, 1987, 1988, 1989, 1990, 1991, 1992, 1993, 1994.)
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: Marin County, California. Areas affected: Drakes Bay, Drakes Estewro, Tomales Bay, Kehoe Beach, Muir Beach.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: January (320 g/100 g tissue), February (11 g), March (230 g), April (680 g), May (220 g), August (330 g), September (930 g).


Causative organism known: Yes
Causative Species/Genus: Alexandrium catenella ( cells/L)
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Alexandrium catenellum.
Event-related bibliography: State of California Department of Health Services. Shellfish Monitoring Program (SDHSSMP). Technical report No. 94-03 thru 94-28.

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; high concentrations of A. catenellum were noted each time the PSP concentrations were recorded in the shellfish.
Additional Environmental information: Warming trend in the sea surface temperatures (SST) following a brief upwelling period.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Sentinel Bay Mussel Saxitoxins STX eq 930 Bioassay-Mouse
Cultured Pacific Oysters Saxitoxins STX eq Detectable Bioassay-Mouse
Kit used: No Type of kit used:
Additional information: Sentinel Bay Mussel (SBM) 930 g; detectable but below alert levels of PSP in Cultured Pacific Oysters (CPO) were evident.
Economic losses:
Management decision: On January 21, 1994 a quarantine was established for sport-harvested mussels which was lifted on March 7th by the Director of the State Department of Health Services. On March 31 a special quarantine was again establiched due to the rapid increase in PSP
Additional harmful effect information: