Shed a tear for the last drops of our wetlands
February 2 is World Wetlands Day. Do we know what a wetland actually is, and why our survival partially depends on them? Two leading Eastern Cape-based Rhodes University wetlands researchers lay out the local and deeper issues
PIPPA HUCHZERMEYER and NICKY HUCHZERMEYER
How and where have we lost them?
Wetlands go by many names. In English they are commonly referred to as wetlands, springs, floodplains or swamps, to mention a few. In isixhosa they are known as imigxobhozo or imithombo, and in Afrikaans as vleilande.
Wetlands come in all shapes and sizes and can occur almost anywhere, even in arid environments.
The basic definition of a wetland is any area where water accumulates and saturates the soil for a prolonged period of time.
They can be permanently wet or just part of the year. This results in a unique landscape with amazing and exceptional plant and animal species.
The only legislated definition of wetlands in SA is contained within the National Water Act (1998) where wetlands are defined as “land which is transitional between terrestrial and aquatic systems, where the water table is usually at, or near the surface, or the land is periodically covered with shallow water and which land in normal circumstances supports, or would support, vegetation adapted to life in saturated soil”.
The latest National Biodiversity Assessment (NBA) for SA, released in 2019, shows that wetlands are high-value ecosystems, but sadly they are also ranked among the most threatened ecosystems in SA.
Researchers have estimated that about 10% of SA’S surface area was historically covered in wetlands. Currently, only 2.2% of SA’S surface area has been mapped as wetlands.
The NBA showed that 15% of these wetlands are in a nearnatural ecological condition and a staggering 67% have been severely modified. The exact number of wetlands lost is unknown.
Every year wetlands are lost even though they are protected by SA legislation.
The key pressures on the wetlands according to the NBA are:
● Changes in the hydrological regime which is the water quantity and availability, such as dam construction, over-extraction from rivers and groundwater, and overgrazing;
● Water quality pollution, such as sewage leaks, litter and dumping of pollutants;
● Loss of natural habitat;
● Invasive alien species which affect biodiversity and wetland function, and;
● Over-exploitation of wetland species such as through overfishing and harvesting of plants.
All these impacts are closely linked to sustainable management of catchments — areas of land in which all water converges on a single point.
This means managing the resources of these areas from the source (mountains) to the sink (such as a river mouth or the ocean) to ensure that the land use practices across the catchment are environmentally and economically feasible and sustainable.
Can a wetland be an ecological countermand and antidote to environmental collapse and catastrophe? They provide important ecosystem services essential both to humans and the environment.
According to the international Ramsar Convention on Wetlands signed in Ramsar, Iran, in 1971, “ecosystem services” refer to the benefits people get from wetlands — flood attenuation (reduced risks of floods), erosion control, carbon sequestration, water purification, water regulation, tourism, cultural values and more.
Researchers in 2019 showed that wetlands worldwide have been estimated to provide ecological services valued at more than R800-trillion a per year.
Ecosystem services are provided for free by the environment. However, environments that are in a bad ecological state no longer provide these ecosystem services. We are responsible to look after these systems.
With a reduction in functioning ecosystems, we push closer and closer to an environmental catastrophe.
In many cases wetlands that are degraded can recover with active restoration and once again contribute to ecosystem services.
Wetland restoration includes grazing management, stabilising erosion within and around wetlands, revegetating areas prone to erosion and reducing inputs of pollutants into wetland systems.
Wetland buffers are vital in helping maintain wetland systems. Buffer zones are legally required around streams, drainage lines and wetlands.
Buffer zones are used in landuse planning to protect natural resources and limit the impact of one land use on another.
SA is rich in a unique suite of wetlands. SA currently has 28 wetland sites that are designated as wetlands of international importance (Ramsar sites).
The Eastern Cape has many interesting wetlands, however, none of the Ramsar sites occur in the province despite its richness in wetlands.
In the mountainous regions wetlands and rivers commonly begin life as springs. As one moves along the land towards the coast, wetlands become larger and can span many kilometres across valley floors.
These wetlands are deeply symbolic in the isixhosa culture and language such as the name Tsitsa — the name of a large river system northeast of Mthatha — relates to the slow release of water out of the wetlands that occur in this catchment.
These wetlands are the source of life that sustains the rivers and livelihoods downstream. Estuaries are also a type of wetland and are found where rivers meet the ocean.
The estuaries along the eastern seaboard of SA, including the estuaries in the Buffalo City Metro, are increasingly becoming threatened not only by direct impacts on the estuaries themselves, such as large-scale developments, but also by upstream land uses.
The combination of frequent and prolonged droughts, illegal clearing of indigenous vegetation and extensive impoundments (dams) have led to negative effects on most of the downstream estuaries and the species occurring in the sea estuaries.
Many species, such as the endemic Estuarine Pipefish (Syngnathus watermeyeri), are sensitive to high levels of sedimentation, nutrients and pollution and hypersaline conditions. All of these are consequences of catchment mismanagement.
One of the major contributing factors is the loss of functional wetlands in the catchment area.
By not protecting our wetlands, we are removing a vital part of our everyday life, and we are contributing to the collapse of ecosystems.
We cannot survive without wetland systems, and wetland systems rely on us as sustainable custodians.
Nicky Huchzermeyer holds an MSC in geography with a focus on fluvial geomorphology (the study of landscape features and the processes that shape them). He has been working in integrated catchment systems in SA, Lesotho, Tanzania and Belize in Central America, and focuses on geomorphological studies, aquatic environments (including wetlands), catchment systems, and geographical information systems (GIS). He works closely with the Rhodes Restoration Research Group which focuses their efforts on the sustainable use of the subtropical thicket biome. Pippa Huchzermeyer is a wetland specialist with a strong interest in wetland geomorphology. She has worked on a variety of wetlands across the Eastern Cape and is in the final stages of finishing her PHD, which explores sediment dynamics in meandering floodplain wetlands in the Tsitsa River catchment.
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