General Information

Event name: US-22-011
Nature of the harmful event:
High Phyto concentration , Seafood toxins
Event directly affected:
Shellfish , Humans
Toxicity detected: Yes (Approximate range: 46-81 g/100 g)
Associated syndrome: PSP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector): California Mussels and Pacific Oysters
Report the outcome of a monitoring programme: Yes (California Department of Public Health - Marine Biotoxin Monitoring Program)
Event occurred before in this location: Yes
Individuals to contact: ZUBKOUSKY-WHITE, Vanessa

Location & Date

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Location: Latitude: , Longitude:
General location information: California - Monterey and San Luis Obispo Counties,
HAB Area code(s): US-20
Additional location information:
Bloom event dates (yyyy/mm/dd): Event Date:2022-10-23
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: PSP detected (< 80 ug/100 g) January- March,


Causative organism known: Yes
Causative Species/Genus: Alexandrium spp. ( 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: Oxygen content (nL/L): Wind velocity:
Temperature (°C): Oxygen saturation %: Current Direction:
Sechhi disk (m): Salinity: Current Velocity:
Nutrient information:
Temperature Range During Event: Max: °C, Min: °C
Salinity Range During Event:
Bloom location in the water column:
Growth Comments
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
California Mussels Saxitoxins 81 g/100g tissue Bioassay-Mouse
Pacific Oysters Saxitoxins 46 g/100g Bioassay-Mouse
Kit used: Yes Type of kit used: NeoGen
Additional information: Shellfish homogenates are received on ice, extracted, and a Neogen rapid test determines whether the mussel sample is positive or negative. Mussel samples that are positive on NeoGen are then tested using a mouse bioassay to determine concentration of PSP toxins. All other species are only tested with mouse bioassay.
Economic losses: Commercial areas in Morro Bay in San Luis Obispo County went under biotoxin restrictions and had more frequent testing. Recreational advisories were placed on San Luis Obispo and Monterey counties when the mussel quarantine was not in effect so potential
Management decision: Recreational advisory was in place, from the time of first positive result above 80 g/100g until all sites had two consecutive samples below 80 g/100g collected 14 days apart.
Additional harmful effect information:
Created at 06:20 on 5 Apr 2023