Wetlands and climate change

Vincent Gono, Features Editor
THE world yesterday and environmentalists in particular, commemorated World Wetlands Day. The day (2 February) marks the anniversary of the signing of the Convention on Wetlands of International Importance — the Ramsar Convention in Ramsar, Iran, on 2 February 1971.

The Ramsar Convention is the only global environmental treaty that deals with a particular ecosystem.

And this year’s international theme for the day is wetlands and climate change and gives a brief on how wetlands can be vulnerable to climate change, being impacted by changes in temperature, rainfall, sea level rise and extreme events.

Wetlands can also play an important role in climate change mitigation and adaptation, through capturing and storing carbon to reduce atmospheric greenhouse gases, and providing resilience to hazards such as flooding, storm surge and sea level rise.

In Zimbabwe, however, these important ecological sites have not been treated with the respect they deserve. They have been taken for granted and this is so because the scope of conservation of water and its sources in the country has been limited to lakes, dams, tanks and other man-made water reservoirs.

Little attention has, however, been paid to the natural sources of so many rivers and perennial streams that feed into the various creations of man — the wetlands, while their many ecological functions have equally been ignored. In fact people have taken it upon themselves to disturb these ecological sites with reckless abandon while ignoring the bigger catastrophe they will be causing in the process — climate change.

And perhaps due to a combination of arrogance, ignorance and failure of a strict policy by the Government to protect these important areas, the country has lived to see various state-of-the-art buildings being erected on wetlands seriously threatening food security in the country and disturbing the natural ecosystem.

One wonders therefore whether the legislation that protects wetlands that states that it is illegal to cultivate or build in wetlands before getting approval from the Environmental Management Agency (EMA) is a loud sounding statement whose applicability is painful or whether its applicability is selective.

This is despite the fact that the country has a rich and clear legislative ammunition on wetlands provided in Section 113 of the Environmental Management Act (Chapter 20:27), Statutory Instrument 7 of 2007 of the Environment Impact Assessment (EIA and the Ecosystems Protection Regulations) which provides for the minister to declare any wetland to be an ecologically sensitive area and gives him/her the power to impose limitations on development in or around such an area.

But by allowing certain state-of-the-art buildings erected on such prohibited areas, the probable assumption one gets is that investing in infrastructure is so valuable that it has to be allowed to disturb the natural ecosystem.

Ecologists and urban planners are, however, always calling on people including the Government to ensure that the legislation governing wetlands is adhered to because the long term effects are known to affect future generations.

The advice is often despised as both individuals and local authorities continue erecting buildings on wetlands and even on flood plains, exposing people to dangers such as flooding.

Local authorities have continued to ignore calls by the Local Government not to build on wetlands and have failed to move people whose houses were in wetlands and flood plains, who have become perennial victims of floods each time the country receives above average rainfall to higher ground.

Some have made it their business to dump waste on these ecological sites of importance thereby disturbing the flora and fauna found on them. And apart from a comprehensive and often not followed legislative framework the country is a member of the Ramsar Convention — an inter-governmental treaty that provides the framework for national action and international co-operation for the conservation and wise use of wetlands and their resources.

By definition a wetland is an area that is seasonally or permanently covered by shallow water or an area where the water table is close to or at the surface where there are water saturated soils and water tolerant plants.

Wetlands, according to EMA, provide an important habitat for a wide variety of wildlife, trap moderate amounts of soil from running off nearby uplands before they enter lakes and streams. They maintain and improve water quality by filtering contaminants and excessive nutrients as well as renew ground water supplies.

Wetlands also help control flooding and reduce flood damage and further support recreational activities including fish, hunting, nature appreciation, and bird watching and are a source of economically valuable products such as wild rice and commercial fishing.

However, the challenges currently facing wetlands in the country are twofold in that while they are threatened and facing extinction from people’s actions, they also risk a bigger phenomenon of climate change.

With climate change the frequency of droughts has reduced water availability resulting in the water table dropping (lowering) to considerable depths that affect crop and biodiversity to access below ground water.

Climate Change co-ordinator in the Ministry of Environment, Water and Climate Mr Washington Zhakata said elevated temperatures caused by climate change were enhancing evaporative losses, and as precipitation is gradually decreasing, there are signs of reduced run-off and discharge into the rivers from the wetlands.

“Indirectly, water abstraction has also increased in wetlands in some areas as well as dry up in non-wetland areas. Water storage in lakes and reservoirs is being significantly affected by changes in precipitation and enhanced evaporation. Many rivers and reservoirs have either ceased to have an outflow or have dried completely during drought conditions. The changing climate is also altering or hampering animal migrations,” he said.

Mr Zhakata added that there were many derivations from wetlands such as hunting, fishing and bird watching.

“Hunting, fishing, bird-watching, and nature photography are just a few of the many activities that people enjoy in wetlands.

“At first, people were not sure about the benefits provided by wetlands. People are now starting to realise the importance of wetlands and are taking actions to protect them. Wetlands can be protected by passing stringent laws and promoting programmes that help protect existing wetlands. People should not be allowed to drain, fill, or build on a wetland unless they receive a permit”.

He said wetlands prevent flooding by holding water much like a sponge adding that by doing so, wetlands help keep river levels normal and filter and purify the surface water.

Research has shown that wetlands accept water during storms and whenever water levels are high. When water levels are low, wetlands slowly release water. Wetlands also release vegetative matter into rivers, which helps feed fish in the rivers.

Wetlands help to counter balance the human effect on rivers by rejuvenating them and surrounding ecosystems. Many animals that live in other habitats use wetlands for migration or reproduction. For example, some birds nest in large old trees, but need shallow areas in order to wade for fish and aquatic life. Amphibians often forage in upland areas but return to the water to mate and reproduce.

Environmentalist Mr Barnabas Mawire said wetlands were important in that they regulate hydrological processes apart from them being home to a number of animal and plant species.

He added that they have a socio-cultural value attached to them and tampering with them negatively affect their cultural value because in some areas they were deemed sacred where people attach a strong cultural significance on them.

“Wetlands are important in that they regulate hydrological processes such as evapo-transpiration and run-off. Tampering with them therefore causes the effects of climate change to be more apparent. Economically, the situation that we have where local authorities use more than eight chemicals to purify water is evidence that wetlands that help purify water have been destroyed and the costs are usually borne by the people.

“Dumping of waste on wetlands should therefore be punishable and necessary education given so that people have an in-depth appreciation of the important ecological sites,” said Mr Mawire.

He added that an Environmental Impact Assessment (EIA) should always be carried out before any developments could be done on wetlands and EMA should always ensure that due processes were followed.