General Information

Event name: US-02-015
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 1 - 117 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
Individuals to contact: CANNON, Deborah F.

Location & Date

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Location: Latitude: , Longitude:
General location information: Clatsop Beaches and central beaches., Oregon.
HAB Area code(s): US-22
Additional location information: Pacific NW, USA. This event was evident along the entire coast line, north to south, but mainly on the Clatsop beaches where razor clam habitat is abundant. Shellfish sampled from coastal bays did not reach toxic levels during this event.
Bloom event dates (yyyy/mm/dd): Start: 2002-10-08,
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Final date: ongoing. The largest wild harvest area for molluscan shellfish in Oregon is Clatsop Beach, on the northern tip of the state. Clatsop Beaches started 2002 open for commercial and recreational harvest. Domoic acid levels ranged from 17 10 ppm from January to April, still declining from the levels seen during an August 2001 closure, (levels peaked at 33 ppm in 9/01). DA levels in razor clams were < 3 ppm by mid-September 2002. DA levels elevated to the 3 5 ppm range in late September. Early October saw a rapid rise in domoic acid levels on Clatsop Beach from 7 - 9 ppm on 10/2/02, to 29 37 ppm on 10/8/02. An closure was issued on 10/10/02, with an advisory to discard any clams harvested after 10/5/02. Unfortunately, this closure occurred during the best digging tides of the fall opening season. Domoic acid levels on Clatsop Beach peaked at 117 ppm late October and had dropped to the 50 90 ppm range by December 2002.Domoic acid in central Oregon coast razor clams elevated a little later and to a lesser peak than the north coast beaches. Levels were 8 ppm on 10/8/02 and rose to 61 ppm on 11/03/02.Mussels from the coastal rocks tested during October of 2002 were 3 15 ppm for domoic acid. DA levels in mussels before and after October was below detection (<1 ppm). Oysters and clams, at the mouths of the north coast bays, also tested in the 3 5 ppm range for domoic acid during October 2002.


Causative organism known: Yes
Causative Species/Genus: Pseudo-nitzschia 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: 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
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Razor clams, Mussels, Other bay clams Domoic Acid DA eq 117 ppm LC
Kit used: Type of kit used:
Additional information:
Economic losses: Closure has unknown but significant impact on commercial razor clam processors and recreational/tourism in the area.
Management decision: Commercial and recreational closure required to comply with FDA and assure public safety.
Additional harmful effect information:
Updated at 03:42 on 26 Jun 2020