General Information

Event name: US-01-007
Nature of the harmful event:
Foam/Mucilage in the coast , Other ( Alexandrium present but not in exceedingly high cell densities.)
Event directly affected:
Toxicity detected: Yes (Approximate range: Shellfish: 535 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: No
Individuals to contact: LANGLOIS, Gregg

Location & Date

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Location: Latitude: , Longitude:
General location information: Humboldt Bay, Bodega Bay south to Monterey Ba, California: Northern, Central.
HAB Area code(s): US-19 US-20 US-21
Additional location information: Extensive and discontinuous. Highe relative abundances in Humboldt Bay, Bodega Bay south to Monterey Bay, and San Luis Obispo south to Santa Barbara.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Date of quarantine levels: 22/08/01-31/10/01. Detection date and Final date = first and last occurrence, respectively, of PSP toxins > 80 ug/100 g. Low positives (PSP toxins) observed in the beginning of July at several locations. Low numbers of Alexandrium were detected in May and June along the coast of Marin and Humboldt, respectively, prior to the detection of toxicity.


Causative organism known: Yes
Causative Species/Genus: Alexandrium spp. ( cells/L)
Qualitative assessment showed cells were common but not abundant.
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information:
Event-related bibliography: Documented in our program's monthly/quarterly reports.

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: Whole column
Growth: Advected
Growth Comments Possible combination of sources given lack of stability in sea surface temperature during June through August.
Additional Environmental information: A warmer, more stable water mass existed by September 10, which is the period of time when PSP toxin levels first exceeded the alert level along the coat of Marin County.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
M. Californianus, M. Edulis, C. Gigas Saxitoxins STX eq 535 Bioassay-Mouse
Kit used: No Type of kit used:
Additional information:
Economic losses:
Management decision: Harvest areas closed when toxin concentration exceeds the alert level. Adjacent areas are placed on batch release pending assay results.
Additional harmful effect information: First concentrations of PSP toxins >80 ug detected in late August in Humboldt Bay, which immediately subsided. By mid-September PSP toxicity increased above the alert level along Marin Coast (north of Golden gate) and persisted until the last week of Octo