KZN freshwater fish species classified as threatened
LEADER of the Aquatic Ecosystem Research Programme at the University of KwaZulu-Natal, Dr Gordon O’Brien, recently attended an International Union for Conservation of Nature and Natural Resources (IUCN) red list assessment workshop for freshwater fishes in southern Africa, where the conservation status of existing and new fish species in KwaZulu-Natal was reviewed and changed. O’Brien is part of specialist team that authored the review, and thanks to his knowledge on local species, is the leading author reviewing those species.
Key outcomes include the revision of a range of new fishes for the province and the listing of many species as threatened due to multiple stressors.
“KwaZulu-Natal had fewer than three freshwater fishes listed as threatened by the early 2000s, which may now be tripled with some species possibly Endangered or Critically Endangered,” said O’Brien.
He added, “The province has close to 100 species of freshwater fishes, many endemic, ... and many new species of barbs (Enteromius spp.) have recently been discovered and described.”
UKZN has worked closely with Ezemvelo over the past three years to look for these barbs in KZN rivers, especially in threatened systems.
“We’ve observed a concerning decline in the average diversity and abundance of many populations of fishes in the province,” said O’Brien, “largely associated with changes in distribution of alien fishes, land use practices and pollution and most importantly the drought, which has decreased availability of surface water in numerous systems. Surviving fishes have also been removed through pollution, habitat change and harvesting by local communities for subsistence and commercial trade. Such extreme conditions have never been observed, even in severe droughts in the 1990’s; the threats to the wellbeing of rivers today are considerably more than those then.”
The workshop was hosted by the South African National Biodiversity Institute (SANBI) and held at the South African Institute of Aquatic Biodiversity (SAIAB) in Grahamstown. Numerous regional scientists and conservationists were in attendance.
O’Brien emphasised that, while KZN-dwellers need fresh water for homes, industries, recreation and waste treatment, it is vital that people learn to look after that water and its inhabitants in return, notably through increasing our knowledge and exploration of water systems.