General Information

Event name: US-94-020
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 282 g STXeq / 100 g tissue.)
Associated syndrome: PSP
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 PSP alert began on the northern beaches in August 1993 in mussels and continued to October 1993.)
Individuals to contact: CANNON, Deborah F.

Location & Date

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Location: Latitude: , Longitude:
General location information: Netarts, Tillamook, and Nehalem., Oregon.
HAB Area code(s): US-22
Additional location information: Entire Oregon coast from California border to Columbia River. North coast bays affected were Netarts, Tillamook, and Nehalem.
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: South: 27 April at Bandon, mussel PSP = 62 g/100 g peaking at 282 g/100g on 23 June with levels less than 40 g/100 g by mid-August. North: 7 May at Roads End with 37 g/100 g, peaking at 199 g/100g on 6 July, levels less than 40 g/100 g by early September. Toxicity in bay clams ranged from 73 g/100 g in Nehalem Bay cockles on 5 July to 98 g/100 g in Tillamook Bay on 6 July.


Causative organism known: No
Causative Species/Genus: Alexandrium catenella ( cells/L)
Not confirmed
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Field staff trained to examine species recorded an increased abundance on the south coast prior to toxicity in mussels.
Event-related bibliography:

Environmental Conditions

Weather: Warmer than normal spring temperatures occurred in April and May. July was very hot. 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 Not known.
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Mussels Saxitoxins STX eq 282 Bioassay-Mouse
Clams Saxitoxins STX eq 73 Bioassay-Mouse
Kit used: No Type of kit used:
Additional information:
Economic losses:
Management decision: Commercial and recreational harvest of shellfish was closed on the north coast on 6 March; southern beaches on 10 June; entire coast closed by 22 June; northern bays were closed on 8 July. South coast reopened on 16 August; north coast bays on 29 July, an
Additional harmful effect information: A large mussel shipper was closed for three weeks before lot sampling assured safety of product. Commercial clam divers in northern bays were closed for three weeks. Limited oyster production in nothern bays monitored by lot sampling.