Harmful Algal Information System: Event US-94-019

General Information

Event name:	US-94-019
Country:	UNITED STATES
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:	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 44.4-46.7º 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:

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:

Growth Comments

Not known.

Additional Environmental 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.