Lara Van Niekerk
Globally estuarine ecosystems’ abilities to sustain functionality and productivity are rapidly deteriorating owing to increasing human pressures. Unless policy-makers and managers intervene, this valuable natural capital will be lost to society. For interventions to be effective, knowledge on the extent of human pressures on estuaries is critical. This study systematically identified and assessed anthropogenic pressures on South African estuaries and their associated impact on ecosystem health. The outcome of the assessment revealed that a third of the country’s freshwater flow no longer reaches the coast, severely impacting at least 20% of estuaries. Wastewater discharges into estuaries amounts to about 840 million litres per day with 33% of estuaries severely affected by pollution-related activities. More than 3 730 tonnes of fish are caught annually in estuaries, severely impacting at least 20% of systems. Destruction of estuarine habitat results in severe impacts in at least 29% of estuaries, with agricultural activities contributing to 10% of change. About 15% of estuary inlets are artificially manipulated which, when combined, affects more than 60% of estuarine area. Alien vegetation has infested at least 40% of estuaries and severely impacted 6% of systems. The assessment provides a useful framework for the prioritisation of restoration actions. Arresting the decline in health on a national scale requires strategic, cross-sectoral resource-use planning and restoration that addresses the allocation of freshwater, wastewater management, fisheries, and urban, mining and agricultural development. Estuaries prioritized for restoration, particularly for water quality improvement, will provide some quick wins for increasing estuary health.
Audio/Video, Conference Presentation, SER2019
Society for Ecological Restoration