General Information

Event name: ZAF-97-001
Nature of the harmful event:
High Phyto concentration , Mass mortalities , Other ( massive rock lobster mass stranding due to low oxygen water)
Event directly affected:
Toxicity detected: No
Associated syndrome: OTHER
Unexplained toxicity:
Species implicated in toxin transmission (transvector):
Report the outcome of a monitoring programme: No
Event occurred before in this location: Yes (similar to this event but not to this scale)
Individuals to contact: MANSFIELD, Lisa

Location & Date

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Location: Latitude: -32.315278, Longitude: 18.331667
General location information: Elands Bay, West Coast
HAB Area code(s): ZAF-01
Additional location information: Dwarskersbos site of the last stranding on 7 May 1997
Bloom event dates (yyyy/mm/dd): Event Date:1997-04-05
Start: 1997-03-06, End: 1997-05-07
Quarantine levels dates (yyyy/mm/dd):
Additional date-related information: Bloom essentially persisted for two months.


Causative organism known: Yes
Causative Species/Genus: Ceratium furca (1-25x10e6 cells/L)
total dinoflagellate concentration
Co-Ocurring Species/Genus: Ceratium lineatum (1-25x10e6 cells/L)
total dinoflagellate concentration
Chlorophyll concentration, if known: >100mg/m3 µg/l
Additional bloom information: very high bottom chlorophyll a concentrations
Event-related bibliography: COCKCROFT, A.C., D.S. SCHOEMAN, G.C. PITCHER, G.W. BAILEY and D.L. VAN ZYL 1999 A mass stranding, or "walk out" of west coast rock lobster, Jasus lalandii, in Elands Bay, South Africa: causes, results and implications. In: Crustacean issues. Vol 12. The biodiversity crisis and crustacea (Ed. by J.C Von Vaupel Klein and F.R. Schram), pp. 673-688 AA Balkema, Rotterdam, the Netherlands.

Environmental Conditions

Weather: Turbidity (NTU): Wind direction: S
Stratified water: Oxygen content (nL/L): < 1ml / litre Wind velocity: < 2 m/s
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:
In situ
Growth Comments
Additional Environmental information: Very low oxygen levels in shallow inshore waters

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: A total of 2000 tonnes of west coast rock lobster were stranded (in comparison to the annual TAC of 1680 tonnes for 1996/97 season)
Management decision: In total, some 318 tonnes of rock lobster were returned to the sea alive in areas unaffected by low oxygen. Monitoring of red tide activity and a proposed early warning system to detect the presence of low oxygen water in Elands Bay.
Additional harmful effect information:
Created at 02:00 on 15 Jun 2018
Updated at 03:25 on 18 Dec 2019