General Information

Event name: GB-94-004
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: 6,751 mu.)
Associated syndrome: PSP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (SOAFD Monitoring Programme.)
Event occurred before in this location: Yes (Regular occurrence every year since 1968 in Forth.)
Individuals to contact: HOWARD, Godfrey , MACDONALD, Elspeth

Location & Date

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Location: Latitude: , Longitude:
General location information: East coast, and North East coast, Scotland and England
HAB Area code(s): GB-01 GB-02 GB-23
Additional location information:
Bloom event dates (yyyy/mm/dd):
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Late April - July. A closure order was placed on the Moray Firth on 23rd June and was lifted on 28th July.


Causative organism known: Yes
Causative Species/Genus: Alexandrium sp. ( cells/L)
Alexandrium cf. Tamarense
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Low concentrations of Alexandrium cf. tamarense were detected in water samples from the Forth area.
Event-related bibliography:

Environmental Conditions

Weather: Summer weather was cool and wet. Turbidity (NTU): Wind direction:
Stratified water: Yes 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:
In situ
Growth Comments Firth of Forth is a known site of Alexandrium cyst abundance, so could be in-situ population.
Additional Environmental information: Water column in the Firth of Forth was well stratified in late April with a thermocline at around 10 m. By late May this statification had broken down.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Wild scallop muscle Saxitoxins 1,210 MU Bioassay-Mouse
Wild scallop gonad Saxitoxins 2,734 mu Bioassay-Mouse
Mussels Saxitoxins 6,751 MU Bioassay-Mouse
Kit used: Type of kit used:
Additional information: PSP was frist detected in Moray Firth shellfish in late April and on 10th May levels in mussels from Firth of Forth had reached 6751 mu, before falling below 400 mu by early June. Wild scallop stocks were also affected with samples from the Moray Firth in early June recording levels of 2734 mu in gonads and 1210 mu in muscle.
Economic losses:
Management decision: A closure order was placed on the Moray Firth on 23rd June and was lifted on 28th July. PSP > closure also in Staithes, Craster and Budle Bay England
Additional harmful effect information: PSP toxins were also detected in brown crab and Nephrops hepatopancreas, but only twice did levels exceed 400 mu.
Updated at 03:58 on 15 Apr 2018