General Information

Event name: US-06-014
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 1 - 190 ppm)
Associated syndrome: ASP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector): None
Report the outcome of a monitoring programme: Yes (Oregon Dept of Agriculture (ODA), Shellfish Sanitation Program (toxins monitoring) and others)
Event occurred before in this location: Yes (Oregon coastal razor clams have been affected by domoic acid producing algae blooms by five other extended closures in the past 10 years)
Individuals to contact: CANNON, Deborah F.

Location & Date

[View larger map]
Location: Latitude: , Longitude:
General location information: Oregon Coast, Pacific NW, USA
HAB Area code(s): US-22
Additional location information: Oregon Coast, Clatsop beaches (northern most county), and north central beaches (next two counties south). Shellfish harvest areas on Clatsop and north and central coast beaches (Astoria - Coos Bay) were open at the beginning of the year, the far south coast (coos bay - CA border) was closed due to toxin residuals from 2005 but opened by June 2006. The DA event of 2006 began in early July and affected the north and north central until early august when levels in shellfish again trended downward.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Detection date: 07/12/06 in razor clams on N coast; 7/25/06 in razors on C coast. Pseudo-Nitzschia cell counts monitored by NOAA grant were elevated to 177k cells/liter on 7/11/06 in N coast samples with all species represented. Final date: DA toxin levels in razor clams declined from 7/25/06 peak of 31 ppm to <20 ppm by 10/04/06. Pseudo-nitzschia cell counts less than 1000 by mid-August. Clatsop Beach on north coast of OR began the calendar year of 2006 in open status for all razor clam harvesting; commercial and recreational. Levels of DA were below 3 ppm 6/29 and Pseudo-nitzschia counts were 3000 per liter on 7/4, just prior to the beginning of the event. During a low tides series in the 2nd wk of July 2006, razor clams and phytoplankton samples were collected. Results of the phytoplankton examinations were available the day before 7/12 lab results for razor clams testing 7/13. Pseudo-nitzschia cells were elevated to 177,000 per liter; razor clams on Clatsop Beach jumped from 2.7 (6/29) to 27 (7/12); and mussels elevated from < 1 to 3.5 ppm DA on a beach 60 mi to the S. Toxin levels in razor clams off agate beach on N central coast rose from 8 ppm DA on 7/10 to 20 on 7/25. The peak of 31 ppm at the So Jetty of the Columbia R on Clatsop Bch. Levels dropped to less than 20 ppm DA in razor clams on the N and N-Central beaches by 10/04/06l. Pseudo-nitschia levels fell to 100 cells per liter by 8/14/06. These areas were reopened to all harvesting by oct 14, 2006. Mussels on the N and N-central coast ranged from 3.5 - 7.6 for DA during July of 2006 but were not closed to harvest. Other species of clams-softshells and butters; were non-detectable for DA during event. Detectable levels of DA were not found in oysters, coastwide during 2006. There was no evidence of a DA producing algae bloom on the S-central or South coast. Razor clams on the south coast were still closed for residual toxins at the beginning of 2006. All areas were open by the end of June 2006 and stayed less than 10 ppm during the N-coast bloom event. Pseudo-nitzschia cell counts were elevated to 12,000 cells per liter on the south coast during july but no changes in DA levels were detected in south coast razor clam samples or any other shellfish species. For the first time in 3 years, at the end of 2006, all areas of the Oregon coast were open to shellfish harvesting; DA levels in razor clams were less than 15 ppm.


Causative organism known: No
Causative Species/Genus: Pseudo-nitzschia spp. (177,000 cells/L)
7/11/06 in water from Clatsop Beach between Astoria Seaside, OR. Beginning in July 2005 Oregon received a grant from NOAA and began collecting and examining plankton from 5 sites.
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Further details of Pseudo-nitzschia percentage break-downs may be available from teh primary state agency for this work - OR Dept of Fish and Wildlife, Matt Hunter, 503-325-2462
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: 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 and mussels Domoic Acid 31 ppm LC
Kit used: No Type of kit used:
Additional information:
Economic losses: Closure has unknown but significant impact on commercial razor clam processors and recreational/tourism in the closed areas.
Management decision: Commercial and recreational closure required to comply with FDA and assure public safety. Recreational closure required to assure public safety. Commercial bait harvesting is also closed to prevent any contaminated product from entering commerce.
Additional harmful effect information: