adminWETLANDS are areas that are seasonally or permanently covered by shallow water or areas where the water table is close to or at the surface, and these are usually characterised by water-saturated soils and water-tolerant or water-loving plants.
They are transition zones between land and open water. Wetlands are essential to the health of our lakes, rivers and streams.
The survival of hundreds of plant and animal species depend on the unique and specialised habitats found only in wetlands.
Wetlands comprise an incredible array of landscapes. They can be found near the banks of rivers and streams, along the edges of lakes and ponds, or in open fields and wooded areas where the water table is near the surface.
Some wetlands may not even appear wet year-round. Wetlands occur widely throughout both rural and urban areas and can be very small or thousands of hectares in size.
In some areas, particularly near cities and towns, wetlands may be the only remaining “wild” spaces.
Throughout the world many different names are used to describe wetland areas. Marshes, vleis, dambos, floodplains, springs are the types of wetlands found here in Zimbabwe.
About the Convention on Wetlands
The Convention on Wetlands (Ramsar, Iran, 1971) is an intergovernmental treaty whose mission is “the conservation and wise use of all wetlands through local, regional and national actions and international co-operation, as a contribution towards achieving sustainable development throughout the world”.
As of October 2010, 160 nations have joined the Convention as Contracting Parties, and more than 1900 wetlands around the world, covering over 186 million hectares, have been designated for inclusion in the Ramsar List of Wetlands of International Importance.
In Zimbabwe, six sites were designated and these are:
1. Victoria Falls
2. Chinhoyi Caves
3. Mana Pools
4. Lake Chivero/Manyame River
5. Dreifontein Grasslands
6. Monavale
Types of Wetlands found in Zimbabwe
- Marshes (Mapani, Maxhaphozi): Marshy areas are home to many kinds of plants and animals, including fish, which are often present in high numbers. Marshes also serve as stopping point for migratory species, especially birds.
- Floodplains: Lie in areas surrounding lakes, such as Lake Kariba, and in areas alongside river. The regular flooding of floodplains gives rise to local areas of nutritious grassland for grazing for wildlife and stock. Floodplains also regulate water flow they act like gigantic sponge, absorbing the seasonal rains, holding them and then slowly releasing them down into rivers.
- Dambos: They act like a sponge, storing large quantities of water during the wet season and gradually releasing it during the dry season.
- Springs (Zvitubu, umithombo): From a major source of water supply for many rural communities. Their occurrence is to a large extent dependent upon climate.
- Temporary pans and vleis: Pans usually have no established vegetation while vleis typically have some emergent plants. Although temporary, these wetlands support a wide variety of highly adapted organisms which can complete their life cycles rapidly, can cope with large fluctuations in temperature and salinity, and can survive desiccation (drying out) or are mobile enough to move to another water body when theirs dries up.
Why are wetlands important?
They are recognised internationally through the Ramsar Convention as one of the most threatened typed of habitat.
The convention, to which Zimbabwe is a signatory, aims to protect wetlands by improving the communities’ understanding of their importance.
The importance of wetlands:
1. Biodiversity: Large and small wetlands are borders between land and permanent water. They become refuge area in drought and often support rare and threatened plants and animals found nowhere else.
2. Plant and animal habitat: Wetlands are homes for many species of water birds, frogs, invertebrates and fish. They also support countless water loving plants such as sedges, rushes and trees.
Many fish, birds and invertebrates use wetlands as breeding grounds and nurseries for their young. Freshwater wetlands are particularly important for the breeding of water birds.
3. Water quality: The flow of water through wetlands is slowed by bank and in-stream plants, allowing sediments to settle. Nutrients, such as nitrogen, phosphorous and other pollutants are removed as water passes through a wetland, improving water quality and decreasing algal blooms downstream.
4. Biological productivity and nutrient recycling: Wetlands are productive ecosystems. They recycle the nutrients that settle as water flows through, which in turn, promotes plant growth. This cycle supports a diversity of plants and animals through seasonal changes.
5. Flood mitigation: Wetlands hold floodwaters and run-off, reducing flood peaks downstream and directing water-flow away from adjacent properties. This reduces erosion and flood damage in the catchment.
How can you help protect wetlands?
There are many ways we can make sure the ecological, economic and social values of our wetlands are maintained. As individuals and as a community we have a responsibility to protect our wetlands and that includes reducing water pollution.
As part of the Ministry of Environment, Water and Climate; the Agency has embarked on a wetland mapping exercise.
All identified wetlands will be legally protected and to date, wetlands in Harare have been mapped and gazetted.
We are now in the fire season, please do not start open fires. Report all unattended fires in your area to EMA, Forestry Commission or ZRP.
Please talk to us. We are always ready to listen. Email: [email protected]; Tel: 04-0305543 Tollfree 08080028.
Online Reporter