General Information

Event name: US-90-015
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 580 g STXeq / 100 g.)
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, 1962-65, 1980, 1982, 1984, 1986, 1988, 1989.)
Individuals to contact: ROSS, Maria R.

Location & Date

[View larger map]
Location: Latitude: , Longitude:
General location information: Marin County., California.
HAB Area code(s): US-21
Additional location information: Drakes Bay Chimney Rock, Drakes Estero Beds #12, #38, Kehoe Beach, Tomales Bay Clam Island and Lawson's Landing.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Two separate episodes occurred. March-April, and August through November. PSP concentrations detected were well above the alert levels, however, the rest of the year detectable levels below the alert were recorded.


Causative organism known: Yes
Causative Species/Genus: Protogonyaulax 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 Comments Most likely in situ growth. No visible red tide conditions reported.
Additional Environmental information: Observation of a toxic dinoflagellate bloom, however, no other data available.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Shellfish (March-April) Saxitoxins 160 Bioassay-Mouse
Shellfish (August-November) Saxitoxins 580 Bioassay-Mouse
Kit used: No Type of kit used:
Additional information:
Economic losses:
Management decision: Emergency quarantine issued for March and April on sport harvested mussels; persons collecting clams and scallops advised to discard viscera or dark parts and only white meat be prepared for human consumption. Annual mussel quarantine in effect May 1 thro
Additional harmful effect information: Presence of Paralytic Shellfish Toxin activity in wild sea mussels, sentinel sea mussels, bay wild mussels, gaper clams, cultured pacific oysters as assayed by the State of California Department of Health Services mouse method.