General Information

Event name: NZ-04-002
Nature of the harmful event:
High Phyto concentration , Mass mortalities
Event directly affected:
Toxicity detected: No
Associated syndrome:
Unexplained toxicity:
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: Yes (National Marine Biotoxin Monitoring Program)
Event occurred before in this location:
Individuals to contact: RHODES Lesley

Location & Date

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Location: Latitude: -36.290556, Longitude: 174.802778
General location information: Leigh, North Island
HAB Area code(s): NZ-02
Additional location information:
Bloom event dates (yyyy/mm/dd): Event Date:2004-02-18
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information:


Causative organism known: Yes
Causative Species/Genus: Ostreopsis siamensis Schmidt 1901 ( cells/L)
1406 * 10^-3 g/FW
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information:
Event-related bibliography: Shears, N. T., & Ross, P. M. (2009). Blooms of benthic dinoflagellates of the genus Ostreopsis; an increasing and ecologically important phenomenon on temperate reefs in New Zealand and worldwide. Harmful algae, 8(6), 916-925.

Environmental Conditions

Weather: Turbidity (NTU): Wind direction:
Stratified water: Oxygen content (nL/L): Wind velocity:
Temperature (°C): Oxygen saturation %: Current Direction:
Sechhi disk (m): Salinity: Current Velocity:
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: occurred following a period of calm sea conditions with warmer than averagewater temperatures.

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:
Management decision:
Additional harmful effect information: Urchins densities declined by 56%-60% at blooms sites over the study period, urchins are extremely important as herbivores and as a resource, threat to coastal food webs and fisheries.
Created at 11:40 on 7 Mar 2018
Updated at 01:14 on 12 Apr 2018