General Information

Event name: NL-90-007
Nature of the harmful event:
High Phyto concentration
Event directly affected:
Toxicity detected: No
Associated syndrome:
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (Phytoplankton Monitoring program. Tidal Waters Division.)
Event occurred before in this location: No
Individuals to contact: WETSTEYN, L.P.M.J

Location & Date

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Location: Latitude: 51.668889, Longitude: 3.195833
General location information: Delta Area,
HAB Area code(s): NL-03
Additional location information: Oosterschelde and Westerschelde stations.
Bloom event dates (yyyy/mm/dd): Event Date:1990-05-01
Start: 1990-05-01, End: 1990-07-31
Quarantine levels dates (yyyy/mm/dd): First detection: 1990-05-01, End: 1990-07-31
Additional date-related information: Before the bloom in the Waddenzee.


Causative organism known: Yes
Causative Species/Genus: Phaeocystis sp. (13,000,000 cells/L)
Station OSR May.
Phaeocystis sp. (4,700,000 cells/L)
Station OSH May.
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: In 1990 Phaeocystis cell numbers were extremely low; the usual spring bloom was absent.
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:
In situ
Growth Comments
Additional Environmental information:

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Kit used: Type of kit used:
Additional information:
Economic losses: Continuous interest of authorities for the high Phaeocystsis occurence and potential economic and environmental effects.
Management decision: None.
Additional harmful effect information:
Updated at 06:06 on 16 Apr 2015