Sadly when most people think of wetland habitats, they tend to associate them with the 4 D’s. Those D’s being: danger, disease, dampness and difficulty. The reality is they are an important and bio diverse habitat which is home to a diverse and often specialist flora and fauna.
What is a wetland?
There is no definitive answer to this question. Wetland habitats cover a fairly broad spectrum of environments. Key features are waterlogged soil which is covered by seasonal or a permanent layer of shallow water. As a result they tend to have a unique soil structure. The flora and fauna which live there have adapted to live in a water saturated environment.
Typical wetland habitats are swamps, marshes and bogs. In many peoples eyes, they are not the most attractive of places and are actively avoided as people associate them with those 4 D’s!
The threats to the worlds wetlands
As urbanisation spreads globally, planners and industrialists are keen to find new land to develop. Wetlands, owing to their negative public perception are seen as ideal areas for development. Primary uses for wetlands are conversion to waste disposal sites, dams, sewage plants, industry, airports or draining them for agriculture or malaria prevention.
One such airport project is the construction of Navi Mumbai international airport. Environmental concerns were raised over the potential loss of mangrove swamps and wetlands. However, these concerns were over ruled by the high court and an estimated site of 121 hectares of forest, 162 ha of mangroves and 404 ha of mudflats will be under concrete, destroying a unique wildlife habitat. In addition to the loss of wetland and other habitats, some 3,500 families will be displaced. The Navi Mumbai International Airport is expected to be operational in 2023.
Southern Africa’s wetlands are also under threat. Principally from agriculture and mining activities. The National Biodiversity Assessment 2011 Report (Driver et al., 2012) stated that 65% of wetland ecosystem types in South Africa are threatened. Of that number 48% are critically endangered. Making wetlands the most threatened of all of South Africa’s ecosystems.
The threat to the Okavango
The Okavango Delta, in Botswana is a wildlife rich haven and its fertile lands and water have long been a draw for agriculture and industry. The Boro river which flows through the region has become a controversial topic for debate. The powerful diamond mining corporations, which contribute so much to Botswana,s economy, have forwarded plans to dredge the river or canalize it in order to improve vital water supplies for their operations. Conservationists concerns are the proposed works are to extend 25kms inside a protected fenced area. The fence was erected to prevent domestic cattle coming into contact with wild buffalo and risk the spread of contagious diseases such as foot and mouth.
The fence acts as more than a barrier to contagious disease. It separates the wilderness habitat from the outer edges of the delta, where people graze livestock. Many see allowing works inside this zone will set a dangerous precedent for future operations to be given the green light.
Wetland habitat benefits
Wetlands provide many benefits to the environment. Their unique soil structure and plant-life means they act as a giant sponge, storing water and slowly releasing it downstream. In doing so they ensure many areas have a constant water supply. They also control potentially damaging flood waters, slowing it down and spreading it over a larger area. This action of slowing flood water down prevents erosion of nutrient rich soil.
The bulrushes, grasses, reeds, waterlilies and sedges which grow in them, not only help to slow flood waters. They also trap sediments and act as water purifiers, trapping nitrogen and phosphates as well as pollutants, like mercury, lead and pesticides. By-products from agricultural and industrial processes further inland. Many communities rely on them for grazing cattle. While the abundant reeds and grasses are used for thatching homes and for basket weaving.
Wetland plants provide food and shelter for a great variety of birds and animals. Many migratory birds use them as stop overs or as breeding grounds. Species, like the Wattled Crane, found in southern Africa, are classed as wetland-dependent and rely on these habitats for breeding. With habitat loss and land degradation, these majestic birds are now under great threat. It is estimated there are only just over 7000 individuals living in the wild today. Urgent action is needed if we are to save them from extinction.
A rich and diverse habitat
Finally a closing thought. If you still see wetlands as damp, disease ridden, difficult and dangerous places to be avoided or developed. Then you might be surprised to know a healthy wetland contains more life, hectare for hectare, than any other habitat on the planet.