General Information

Event name: US-91-011
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 3,300 g STXeq /100 g of wild sea mussels.)
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, 1930, 1932, 1937, 1954, 1962, 1968, 1969, 1970, 1971,1976, 1980, 1981,1982, 1984, 1987, 1989, 1990.)
Individuals to contact: ROSS, Maria R.

Location & Date

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Location: Latitude: , Longitude:
General location information: Sonoma County., California.
HAB Area code(s): US-21
Additional location information: Salt Point State Park, Bodega Head, Sea Ranch, Mussel Point, Doran Rocks (Wild Sea Mussels); Bodega Harbor/Doran Park, Bodega Harbor/Inner, Bodega Bay, Bodega Head, Bodega Harbor/USCG Dock (Washington Clam); Bodega Bay (Basket Cockle).
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: July- August, October - December.


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:
Growth: Advected
In situ
Growth Comments Both advected population and in situ growth. The bloom of the dinoflagellate traced to Mendocino County.
Additional Environmental information: No data available.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Wild Sea Mussels Saxitoxins STX eq 3,300 Bioassay-Mouse
Washington Clam Saxitoxins STX eq Bioassay-Mouse
Basket Cockle Saxitoxins STX eq Bioassay-Mouse
Kit used: No Type of kit used:
Additional information:
Economic losses:
Management decision: Although the California Annual Quarantine was in effect a special quarantine was established by the Director of Health Services on July 25 to include all bivalve shellfish taken by sport harvesters.
Additional harmful effect information: During July, August paralytic shellfish toxin levels assayed reached a high of 3,300 g/100 g of wild sea mussels decreasing to below alert concnetration and in November the level increased to 110 g. During the rest of the 1991 the wild sea mussels level