General Information

Event name: NL-87-001
Nature of the harmful event:
Seafood toxins
Event directly affected:
Toxicity detected: Yes (Approximate range: DSP Positive ratbioassay)
Associated syndrome: DSP
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (RIVO Shellfish Monitoring)
Event occurred before in this location: Yes (DSP outbreaks in 1961, 1971, 1976, 1979, 1981, 1986.)
Individuals to contact: KAT, Marie , POELMAN, Marnix

Location & Date

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Location: Latitude: 53.328056, Longitude: 5.234444
General location information: Dutch Waddensea,
HAB Area code(s): NL-01
Additional location information:
Bloom event dates (yyyy/mm/dd): Event Date:1987-09-15
Start: 1987-08-15, End: 1987-10-01
Quarantine levels dates (yyyy/mm/dd): First detection: 1987-09-15, End: 1987-11-15
Additional date-related information:


Causative organism known: Yes
Causative Species/Genus: Dinophysis acuminata (100 cells/L)
water samples in period august - sept
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: No Chlorophyll measurements. µg/l
Additional bloom information: Identification no problems.
Event-related bibliography:

Environmental Conditions

Weather: Turbidity (NTU): Wind direction:
Stratified water: No Oxygen content (nL/L): Wind velocity:
Temperature (°C): 17.5 Oxygen saturation %: 100 Current Direction:
Sechhi disk (m): Salinity: Current Velocity: 0
Nutrient information:
Temperature Range During Event: Max: 17.5 °C, Min: 10 °C
Salinity Range During Event:
Bloom location in the water column: Whole column
Growth: Advected
Growth Comments Mussel beds in shallow waters effected.
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Mussels Okadaic Acid OA Positive Bioassay-Rat
Mussels Okadaic Acid DTX1 Positive Bioassay-Mouse
Kit used: No Type of kit used:
Additional information: DSP in mussels (all sizes). Rat bioassay (positive).
Economic losses:
Management decision: Area closed for shellfish fishery from mid september through mid November.
Additional harmful effect information:
Updated at 05:04 on 16 Apr 2015