General Information

Event name: ZAF-88-001
Country: SOUTH AFRICA
Nature of the harmful event:
Water Discoloration , High Phyto concentration , Seafood toxins , Mass mortalities
Event directly affected:
Natural Fish , Shellfish , Humans
Toxicity detected: Yes (Approximate range: Not specified)
Associated syndrome: OTHER , Aerosolized toxins effects
Unexplained toxicity: No
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: No
Event occurred before in this location: No
Individuals to contact: MANSFIELD, Lisa

Location & Date

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Location: Latitude: -34.221667, Longitude: 18.759167
General location information: False Bay, South Coast
HAB Area code(s): ZAF-02
Additional location information: During 1988 the furtherest station where sampling occurred is Hermanus in the Walker Bay area.
Bloom event dates (yyyy/mm/dd): Event Date:1988-05-24
Start: 1988-04-16, End: 1988-05-24
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information:

Microalgae

Causative organism known: Yes
Causative Species/Genus: Gymnodinium sp Horstman et al. 1991 (17127668 cells/L)
on 1988-05-24 at Gordons Bay
Co-Ocurring Species/Genus:
Chlorophyll concentration, if known: µg/l
Additional bloom information:
Event-related bibliography: HORSTMAN, D.A., S. MCGIBBON, G.C. PITCHER, D. CALDER, L. HUTCHINGS and P. WILLIAMS 1991 – Red tides in False Bay, 1959-1989, with particular reference to recent blooms of Gymnodinium sp. Transactions of the Royal Society of South Africa 47: 611-628.

Environmental Conditions

Weather: calm Turbidity (NTU): Wind direction:
Stratified water: Oxygen content (nL/L): Wind velocity:
Temperature (°C): 14.2 - 18 Oxygen saturation %: Current Direction:
Sechhi disk (m): Salinity: Current Velocity:
Nutrient information: NITRATE: 0.2 - 13.5 mmol.m-3
Temperature Range During Event: Max: 18.0 °C, Min: 14.2 °C
Salinity Range During Event:
Bloom location in the water column: Whole column
Growth: Advected
Growth Comments The bloom was much more localised, being mainly in Gordons Bay and Strand, but spreading a little to Koeelbaai and Hermanus.
Additional Environmental information: Bathers and fishermen suffered from eye, nose and lung irritations during the bloom.

Toxin Assay Information

Species containing the toxin Toxin type Toxin details Max. concentration Assay type
Gymnodinium sp Brevetoxins Bioassay-Other
Kit used: Type of kit used:
Additional information: A sea-urchin assay was performed on water samples collected on 16 May 1988.
Economic losses:
Management decision:
Additional harmful effect information: Bathers and fishermen suffered from eye, nose and lung irritations during the bloom.
Created at 03:03 on 18 Apr 2018
Updated at 09:59 on 25 Aug 2020
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