CAPE TOWN, April 9 (Xinhua) -- A South African conservation agency has warned that invasive red swamp crayfish are spreading at an alarming rate across the country's Western Cape Province, posing a serious threat to fragile local freshwater ecosystems.
In a statement posted on Wednesday, CapeNature said the species, scientifically known as Procambarus clarkii, has expanded beyond its initial detection site after first being recorded a few years ago in a river in the province.
"Since first being found in the canal systems of the lower Olifants River in 2022 by CapeNature officials, invasive red swamp crayfish are being found further afield in the Western Cape at an alarming rate," the agency said.
The freshwater species is globally recognized as "seriously damaging invasive" and was originally introduced for aquaculture and the ornamental pet trade, the agency said.
CapeNature warned that the threat is particularly severe because continental Africa has no native crayfish. "Therefore, the threat posed by this species is considerable as the fragile freshwater systems and species of the Western Cape are not adapted to crayfish," it said.
According to the agency, the species can disrupt ecosystems by feeding across multiple trophic levels, damaging fisheries and reshaping ecological systems once established. They can also carry aquatic diseases, destabilize riverbanks through burrowing, and damage irrigation infrastructure.
"It is essential that this species does not continue to establish in the Western Cape, as the ecosystem engineering capacity of Red Swamp Crayfish may alter the unique habitats permanently," it said.
CapeNature urged the public not to release crayfish into the wild and to report sightings, noting the species' ability to survive out of water for extended periods.
CapeNature is a government entity responsible for managing and maintaining 31 nature reserve complexes comprising 112 nature reserves, of which 106 are terrestrial and six are marine protected areas, totaling 828,506 hectares in the Western Cape. ■
