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SUSTAINABILITY SUPPLEMENT Pans have little impact on the environment as individual water sources, but collectively they have the ability to affect climate change as well as biodiversity Prevention is better than cure South Africa’s wetlands are highly protected ecosystems, particularly if your business is mining. The same however cannot be said for the country’s vast pan ecosystems, which if neglected and polluted will have devastating impacts on local biodiversity in the long-term, Jeffares & Green’s senior aquatic scientist Dr Martin Ferreira tells Laura Cornish. areas included Mpumalanga, the Free State and North West provinces. IN SHORT South Africa’s pans are under threat and human intervention is required to protect them, not destroy them. A ccording to Ferreira, pans are classified as wetlands in South Africa, but have been neglected in terms of research and monitoring when compared to other wetland ecosystems. By definition they are isolated, ephemeral shallow depressions, drawing water from rainfall and subsurface flows as they have no connection with a water inlet or outlet system. Their lifespans are cyclical, losing their water (over varying periods of time) through evaporation. Because of these characteristics, pans are often restricted to arid regions with complete desiccation occurring seasonally. Although generally restricted to the drier western parts of South Africa, pans are also present in the eastern Highveld region where rainfall often exceeds 750 mm a year. This has seen a large volume of pans emerge over centuries in Mpumalanga – South Africa’s largest coal mining region. 58 MINING Liqhobong diamond mine. REVIEW AFRICA ISSUE 4 2014 “Compared to wetlands, pans have received very little research dedication, despite being classified as a type of wetland (endorheic) in South Africa. I believe this is largely because they are mostly temporary and provide few ecosystem services. South Africa is home to thousands and thousands of pans, some small, some extremely large. They have little impact on the environment as individual water sources, but collectively they have the ability to affect climate change as well as biodiversity, directly and indirectly,” Ferreira outlines. Ferreira, together with the University of Johannesburg and Water Research Commission, has spent the last seven years evaluating three large pan areas, focused on determining the ecological functioning of the pans. Two of the three areas chosen are heavily populated with mines, whose potential impact (from acid mine drainage (AMD)) was incorporated into the study. The three “I cannot deny the difficulties associated with evaluating pans,” Ferreira notes. “Because they are temporary environments, they have short hydro-periods and evolve alongside natural weather patterns and conditions. Studied in isolation, it cannot be properly determined how anthropogenic activities are impacting on them.” “Ephemeral pans do however provide a biological template for a unique group of fauna in the form of different branchiopod crustaceans and certain aquatic insects that are able to adapt to the harsh environments associated with pans,” Ferreira continues, referring to a paper he has written on this subject as part of his PhD. Such crustaceans have not only adapted to live in such environments, but further require a pan’s evolutionary lifecycle to survive. “As such, they are a good indication of the pan’s ecological integrity.” Branchiopod crustaceans are aquatic species and include a variety of fairy shrimps and water fleas. They lay their eggs in the uppermost sedimentary layer at the bottom of pans. These eggs don’t hatch