General Information

Event name: GB-96-003
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 555 g STXeq /100 g Mussels.)
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 (PSP has regularly occurred in Orknwy since 1990.)
Individuals to contact: HOWARD, Godfrey , MACDONALD, Elspeth

Location & Date

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Location: Latitude: , Longitude:
General location information: Orkney Islands., Scotland.
HAB Area code(s): GB-20
Additional location information:
Bloom event dates (yyyy/mm/dd): Start: 1996-04-23, End: 1996-09-23
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information:


Causative organism known: Yes
Causative Species/Genus: Alexandrium spp. (2,000 cells/L)
May at Scapa Flow.
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Alexandrium spp. observed at two sites in Orkney until July with highest levels found in May (2000 cells/L) at Scapa Flow.
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 Not known.
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Scallops Saxitoxins STX eq 640 Bioassay-Mouse
Velvet crabs Saxitoxins STX eq 27 Bioassay-Mouse
Mussels Saxitoxins STX eq 555 Bioassay-Mouse
Kit used: No Type of kit used:
Additional information: PSP in mussels (max. 555 g/100 g) mostly in Scapa Flow, Kirkwall Bay and Wide Firth. Other species affected included cockles, scallops, queen scallops and razor fish. Low levels (up to 27 g/100 g) in velvet crabs. Scallops from east of Orkney contained up to 640 g/100g.
Economic losses:
Management decision: FEPA 1985 closure order imposed on 17/07/96 and revoked on 23/09/96 for offshore scallop gonads.
Additional harmful effect information: Low levels of PSP detected in scallop gonads during winter 1995-96.
Updated at 11:09 on 14 Sep 2016