General Information

Event name: ZAF-66-001
Nature of the harmful event:
Water Discoloration , High Phyto concentration , Seafood toxins , Mass mortalities
Event directly affected:
Toxicity detected: Yes (Approximate range: Yes, but no specific range given)
Associated syndrome: OTHER
Unexplained toxicity: No
Species implicated in toxin transmission (transvector): White mussels, Donax serra and Black mussels, Choromytilus meridionalis
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: -32.312778, Longitude: 18.338056
General location information: Elands Bay, Western Cape
HAB Area code(s): ZAF-01
Additional location information: extends from a few miles south of St. Helena Bay to at least 50 miles northwards.
Bloom event dates (yyyy/mm/dd): Event Date:1966-12-21
Start: 1966-12-21, End: 1967-01-05
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information:


Causative organism known: Yes
Causative Species/Genus: Gonyaulax grindleyi Reinecke 1967 (6667500 cells/L)
Now know as Protoceratium reticulatum
Co-Ocurring Species/Genus: Eutreptiella sp. (835000 cells/L)
Chlorophyll concentration, if known: µg/l
Additional bloom information: Diatoms were co-occuring species as well as non-toxic Gyrodinium obtusum
Event-related bibliography: GRINDLEY, J.R. and E.A. Nel 1970 - Red water and mussel poisoning at Elands Bay, December 1966. Fish. Bull. S. Afr 06: 36-54

Environmental Conditions

Weather: calm Turbidity (NTU): Wind direction: NW
Stratified water: Oxygen content (nL/L): 5.32 - 6.90 Wind velocity:
Temperature (°C): 14.0 - 17.5 Oxygen saturation %: Current Direction: S
Sechhi disk (m): Salinity: Current Velocity:
Nutrient information:
Temperature Range During Event: Max: 15.07 °C, Min: 12.79 °C
Salinity Range During Event:
Bloom location in the water column:
Growth: Advected
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:
Management decision:
Additional harmful effect information: This bloom resulted in the death of hundreds of thousands of White mussels (Donax serra) and large numbers of Black mussels (Chloromytilus meridionalis) and many other marine invertebrates.
Created at 12:09 on 17 Apr 2018
Updated at 07:12 on 13 Nov 2018