A New Invader in the Western Cape Province: The Red Swamp Crayfish
A concerning new discovery was made in Vredendal where the North American Red Swamp Crayfish (Procambarus clarkii) was detected in the Lower Olifants River irrigation system. The crustacean is a notorious invader of many countries worldwide and can have negative ecological and economic impacts. There are no naturally occurring freshwater crayfish in Africa.
Due to the active response of the farmer who found them and swiftly alerted the authorities, CapeNature was able to rapidly conduct an inspection. Unfortunately, the findings of the inspection were not good as a well-established population of Red Swamp Crayfish was found in the canals and related water bodies in the Vredendal area.
The next steps will be to establish the full extent of invasion and work out the origin of invasion. To assess where they came from, CapeNature is collecting DNA samples for comparison to existing populations. Once this information has been received, a response plan can be developed by the relevant authorities to combat the impacts of this invasive alien species. Any new sightings of this species in the province are to be reported to CapeNature: Dr Martine Jordaan, mjordaan@capenature.co.za
A Red Swamp Crayfish (Procambarus clarkii) captured in the Lower Olifants Irrigation Scheme in Vredendal (photo credit Dr Andrew Turner).
Dr Andrew Turner sampling the inflow canal and collecting several Red Swamp Crayfish (photo credit Dr Martine Jordaan).
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