Wetlands are vital in ecosystem performance and functions as they provide products and possess attributes that are beneficial to almost all forms of life.

 

By Felicity Nyamakupe

What are wetlands?

Wetlands are areas where water covers the soil or is present either at or near the surface of the soil all year or for varying periods of time during the year including during agricultural cropping seasons.

 They occur where the water table is at or near the surface of the land or where the land is covered by water.

Most wetlands are natural while some are human-made.

Importance of Wetlands

Wetlands are vital in ecosystem performance and functions as they provide products and possess attributes that are beneficial to almost all forms of life.

Wetlands act as a habitat for fish, wildlife and plants.

They serve as a biologically diverse ecosystem.

It improves the water quality and hydrological processes that take place within diverse water systems.

 Wetlands also serve as natural sewage treatment systems by absorbing chemicals, filtering pollutants and sediments, breaking down suspended solids and neutralizing harmful bacteria. Wetlands also assist in flood protection by storing and slowly releasing surface water, rain, groundwater and flood water.

 Trees and other wetland vegetation also impede the movement of flood waters.

Wetlands also act as recreation or tourism, education and research areas.

Wetlands transform communities into economic and food secure communities as they can sustain crops, livestock and wildlife.

 What drives wetland loss and degradation?

Agriculture is one of the major drivers of wetland depletion through stream bank cultivation. This leads to soil salinization, sediment deposition, erosion and eutrophication.

Grazing animals degrade the condition of wetlands by compacting soils, dispersing the seeds of weeds, trampling vegetation and contaminating the water with animal waste.

 The increased population has led to infrastructure development in wetland areas hence their depletion.

 Water diversion through dams, dykes, and canalisation lead to dramatic changes to groundwater-storing.

 Waterlogging has been suggested to affect carbon (C) turnover in wetlands and it reduces soil respiration.

 The cultivation of forest trees has led to reduced infiltration and has led to a high risk of flood occurrence.

The drilling of boreholes has led to the reduction of the water table therefore thereby negatively impacting wetlands.

Impacts of Wetland Degradation

As a result of the degradation of wetlands, there is a loss of all the benefits that they provide.

Water scarcity is being experienced in Zimbabwe as a result of the depletion of the wetlands and this is mostly due to infrastructure development.

 There is an increase in the loss of biodiversity. The species that survive in the wetlands become extinct.

 The rate of runoff and flash floods will increase due to the reduced infiltration of water.

What does the law say about Wetlands?

Wetlands in Zimbabwe are protected by law and authority for their utilisation may be granted by the Environmental Management Authority, EMA.

The Ramsar Convention is an inter-governmental treaty whose mission is “the conservation and wise use of all wetlands through local, regional and national actions and international cooperation as a contribution towards achieving sustainable development throughout the world”.

Zimbabwe is a signatory to the Ramsar Convention on Wetlands of 1971 and has domesticated provisions for the protection of wetlands under the Environmental Management Act (Cap 20;27), Statutory Instrument 7 of 2007 on Environmental Management (Environmental Impact Assessment and Ecosystems Protection) Regulations and  Government Gazette 380 of 2013. Failure to abide by the law is a crime and a fine has to be paid or imprisonment not exceeding two years.

The wetlands of Zimbabwe

Wetlands come in many different forms. They can be tidal zones, marshes, pans, flood plans,  bogs or swamps among many other types.

However, they all share characteristics that make them wetlands.

Mana Pools in Chinhoyi, Driefontein Grasslands in Chivhu, Cleveland Dam, Lake Chivero and Manyame, Monavale Vlei and Victoria Falls have been declared Ramsar sites in the country.

The way forward

Under an ever-changing climatic environment the human –wetland interface for survival cannot be ignored.

The depletion of wetlands is proving to be a big problem that needs to be addressed because if it is not attended to urgently the wetlands will be depleted to a state of no recovery.

The communities are urged to sustainably manage the wetlands to avert water scarcities that are occurring due to Climate Change.

There is a need for an increase of public awareness on the importance of wetlands.

Laws on wetlands protection need to be reinforced.

The wise use of the wetlands needs to be emphasised while preservation and conservation of wetlands is very important. Projects on the restoration of wetlands should be implemented through the education of people. Communities, businesses and governments need to work together to protect these amazing ecosystems which in turn will help us adapt to the impacts of Climate Change.

 The Zimbabwe National Water Authority (Zinwa) has already raised the red flag, saying due to the destruction of wetlands in Harare the water table has drastically gone down and the situation could worsen if action to save the water sources is not taken.

Wetlands and Climate Change

Wetlands play the role of buffering Climate Change and they are important for helping to mitigate Climate Change because they manage extreme weather events through the multiple services they provide like flood mitigation.

 Wetlands assist in drought mitigation by allowing water to reach the surface of the water table thereby making the resource available in dry periods.

 Floods are also prevented as a result of water absorption and storage in the soil.

Wetlands are significant carbon stores for Climate Change regulation and their loss and degradation is a major concern as it contributes to global warming by transforming natural carbon sinks into emission sources.

The wetlands buffer the coastlines from extreme weather like storm surges.

Wetlands are also among the ecosystems most vulnerable to Climate Change.

Inland and freshwater wetlands are likely to be affected by increased temperatures and changes to precipitation and more frequent or intense droughts, storms, and floods.

Climate Change results in the degradation of biodiversity and ecosystem activities and it negatively impacts human and animal communities.

-ACCCKF