General Information

Event name: NL-91-004
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: 53.167778, Longitude: 5.077222
General location information: Wadden Sea,
HAB Area code(s): NL-01
Additional location information:
Bloom event dates (yyyy/mm/dd): Event Date:1991-04-01
Start: 1991-04-01, End: 1991-09-15
Quarantine levels dates (yyyy/mm/dd): First detection: 1991-04-01, End: 1991-09-15
Additional date-related information: Total bloom/prevalence April-September.


Causative organism known: Yes
Causative Species/Genus: Phaeocystis sp. (5,000,000 cells/L)
Station E30.
Phaeocystis sp. (4,000,000 cells/L)
Station E250.
Phaeocystis sp. (6,000,000 cells/L)
Station W590.
Phaeocystis sp. (20,000,000 cells/L)
Station W420.
Phaeocystis sp. (6,000,000 cells/L)
Station W30.
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information: Highest cell numbers were counted during the spring bloom in April-May. After the spring bloom values were between ca. 10,000 and 10,000,000 cell/L, although sometimes values >>1,000,000 cell/L. Were measured.
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
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: None.
Management decision: None. The goverment focusses on Phaeocsytsis as a nuisance species.
Additional harmful effect information:
Updated at 06:25 on 16 Apr 2015