General Information

Event name: US-04-021
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 1 - 87 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, Shellfish Sanitation Program)
Event occurred before in this location: Yes (Yes, Oregon coastal razor clams have been affected by domoic acid producing algae blooms by 3 other extended closures.)
Individuals to contact: CANNON, Deborah F.

Location & Date

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Location: Latitude: , Longitude:
General location information: Oregon, Clatsop Beaches (northern most county, Pacific NW, USA
HAB Area code(s): US-22
Additional location information: This event was continued from 2003 along the entire coast line, north to south, affecting the following named beaches: Clatsop, Newport-Waldport, ocean spits of Umpqua & Coos Bays and Gold Beach. These are beaches where razor clam habitat is abundant although variable. Bay clams and mussels 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: 01/10/03 for Clatsop Beach or north coast; ongoing for central and south coast beaches Clatsop Beach on north coast of Oregon began the calendar year of 2004 in open status for all razor clam harvesting; commercial and recreational. Levels of DA were below 5 ppm during the first half of 2004 and in June & July several samples were below detection (<1 ppm). Aug and Sept saw a slight elevation to a range of 6 - 8 ppm. Levels declined again in the fall to < 5 ppm again in Dec 2004.Domoic acid levels in razor clams on the central coast beaches of Newport - Walport (recreational only) were still declining from 2003 highs (287 ppm); levels in Jan- June 2004 ranged from 50-30 ppm. July to mid Aug DA dropped to 20ís but mid Aug saw another elevation to 48 and 33 for razor clams from the N end of Newport beaches. By Oct - Nov of 2004 DA levels on Newport-Waldport beaches returned to mid 20ís.Other species of clams- softshells and butters; mussels and oysters (Pacifics), on the north & central coast showed no detectable levels of domoic acid all year round.During 2004, DA in south coast razor clams continued declining from 2003 highs (100 ppm); levels in Jan- April 2004 ranged in 20ís. In early May an elevation of DA was seen in extreme So coast mussels (7 -10 ppm) then 1 wk later razors jumped to 46 ppm and by June 2 Gold Beach razor clams were at 87 ppm. Mussels dropped to below detection within the next week. The Umpqua and Coos Bay ocean spits were not affected by the apparent DA bloom in May; these areas continued to drop, DA levels were < 20 by Oct permitting an opening of these two spits. By Sept, Gold Beach razor clams again dropped to 20 ppm range for DA but in mid Sept low levels were seen again in mussels (2 ppm); razors went up to 48 by end of Sept; levels still in 40ís by end of year.To summerize, at the end of 2004, two large recreational beaches - Newport-Walport and Gold Beach have been closed to razor clamming, due to DA contamination, since Nov 2002. (At the time of writing this 2004 summary, March 2005, the Newport-Walport beach has opened.)


Causative organism known: No
Causative Species/Genus:
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 87 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: