The Australian red-claw crayfish is on the move in the Kafue and Zambezi River systems, to the delight of gourmets (it tastes like lobster), doctors (it feeds on the vector snails for Schistosomiasis (bilharzia), having practically eradicated the disease in some areas) and business (it comprises an export venture just waiting to happen).
However, environmentalists are horrified, as the crayfish is an invasive species (see Fact Box). Crayfish can be extremely disruptive in aquatic ecosystems where they have no natural predators or diseases to keep them in check.
How the Australian red-claw crayfish ended up in Zambia is unclear. Some say it was introduced by a fish farm in Lake Kariba in the 1990s, while others talk about Livingstone in 1992. The crayfish has definitely spread since then, perhaps aided by one or more secondary re-introductions. Allegedly, Chinese road contractors released some crayfish near Mongu in 2014, and two years later the crayfish was found near Katima Mulilo. Scientists are now worried that it may reach the fragile Okavango Delta in Botswana.
Even though crayfish have proven almost impossible to eradicate once established, their spread can potentially be limited through control measures such as traps, physical barriers and targeted biological control. Thus, the Kafue River Trust and the Lower Zambezi Catch & Release Initiative are calling on people to help it monitor the crayfish’s advance. Any sightings by fishermen, anglers, tourism guides and the general public can be reported to email@example.com. More information at www.kafuerivertrust.org.