General Information

Event name: US-20-008
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 139-3498g/100g)
Associated syndrome: PSP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (Marine Biotoxin Program at the Washington State Department of Health, Office of Environmental and Health and Safety.)
Event occurred before in this location: Yes
Individuals to contact: BORCHERT, Jerry

Location & Date

[View larger map]
Location: Latitude: , Longitude:
General location information: Puget Sound, Washington
HAB Area code(s): US-24
Additional location information:
Bloom event dates (yyyy/mm/dd): Start: 2020-07-15, End: 2020-12-03
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information:


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: 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
Blue mussels Saxitoxins 3498g/100g Bioassay-Mouse
Geoduck clams Saxitoxins 1054g/100 Bioassay-Mouse
Butter clams Saxitoxins 430g/100g Bioassay-Mouse
Manila clams Saxitoxins 582g/100g Bioassay-Mouse
Pink scallop Saxitoxins STX 147g/100g Bioassay-Mouse
Varnish clam Saxitoxins 167g/100g Bioassay-Mouse
Cockles Saxitoxins 139g/100g Bioassay-Mouse
Littleneck clams Saxitoxins 93g/100g Bioassay-Mouse
California mussels Saxitoxins 1396g/100 Bioassay-Mouse
Horse clams Saxitoxins 220g/100g Bioassay-Mouse
Kit used: No Type of kit used:
Additional information:
Economic losses: Recreational and commercial shellfish harvest seasons were interrupted, causing an economic loss to the Central Puget Sound Washington communities
Management decision: WADOH closed shellfish harvesting at impacted areas to protect public health.
Additional harmful effect information:
Created at 11:18 on 19 Apr 2021