General Information

Event name: US-94-019
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 24 ppm DA.)
Associated syndrome: ASP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes
Event occurred before in this location: Yes (The last Oregon domoic acid alert began on the northern beaches in November in razor clams and continued to exceed 5 ppm until July 1992.)
Individuals to contact: CANNON, Deborah F.

Location & Date

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Location: Latitude: , Longitude:
General location information: Clatsop Beaches., Oregon.
HAB Area code(s): US-22
Additional location information: Oregon coast from Cape Lookout near Netarts to the Columbia River (approximately 44.4-46.7 N). This area is called the Clatsop Beaches.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Toxicity in razor clams began in November 1993 when domoic acid levels increased to 10 ppm. This was the first time levels exceeded 6ppm since November 1992. Mussels were 1 ppm, the first time detected since November 1992. DA levels rose to 24 ppm in January and declined to less than 4 ppm bya April. Levels less than 5 ppm in bimonthly sampling for the rest of 1994.


Causative organism known: No
Causative Species/Genus:
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Not confirmed.
Event-related bibliography:

Environmental Conditions

Weather: Typical late summer and fall weather conditions. Fall rains began in early November which is later than usual. 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: 13 °C, Min: 10 °C
Salinity Range During Event: Max: 30, Min: 25
Bloom location in the water column:
Growth Comments Not known.
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Razor clams (Nov. 1993) Domoic Acid DA eq 10 ppm Bioassay-Mouse
Razor clams (January 1994) Domoic Acid DA eq 24 ppm Bioassay-Mouse
Razor clams (rest 1994) Domoic Acid DA eq 5 ppm Bioassay-Mouse
Kit used: No Type of kit used:
Additional information:
Economic losses:
Management decision: Commercial and recreational harvest of razor clams was reopened on Clatsop Beaches on 1 November for the first time since November 1991.
Additional harmful effect information: The razor clam fishery was already closed.