Harmful Algal Information System: Event US-91-011

General Information

Event name:	US-91-011
Country:	UNITED STATES
Nature of the harmful event:	Seafood toxins
Event directly affected:	Humans
Toxicity detected:	Yes (Approximate range: 3,300 痢 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.

Microalgae

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 痢/100 g of wild sea mussels decreasing to below alert concnetration and in November the level increased to 110 痢. During the rest of the 1991 the wild sea mussels level