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WETLANDS: WASTELANDS OR SOURCES OF WEALTH?

Wetlands have often been seen as wastelands, with governments seeking to 
drain them both to eliminate malaria and other water-borne diseases and to 
create more agricultural land. But now the world's swamps, bogs and marshes 
are coming back into their own as science discovers the vital role they 
play in regulating water quality and quantity and influencing the local 
climate.

By Barry James


An estimated 50% of the world's wetlands, ranging from the 
fast-disappearing mangrove swamps in East Asia to the environmentally 
challenged Jamaica Bay marshes in the heart of New York, have disappeared 
in the last 100 years. Many of those that remain have been fragmented with 
dams, sluices and canals.

Mostly the wetlands have receded under the pressure from growing 
populations and cities. But sometimes they have been deliberately 
eradicated as in Iraq, where the former regime drained most of the vast 
extent of marshlands that stood between the Euphrates and Tigris rivers 
since the dawn of history and turned much of its population into refugees.

Admittedly, the idea of 'reclaiming' the Iraqi marshes and using the water 
for irrigation was originally a British plan, but that was before 
scientists knew about the complex interaction between water, land and 
climate and the key role of the wetlands in protecting a diversity of 
birds, fishes and plants. Now the draining of the Iraqi marshes is seen by 
the United Nations, the European Parliament and by many non-governmental 
organisations as a tragic and probably irreversible assault on culture and 
environment.

Patrick Denny,  a  wetlands scientist,  has spent much of his career in 
Uganda,  the second country in the world after Canada to grant official 
protection to its extensive wetlands by constitutional law. He says a good 
wetland acts as both a sponge and a filter.

'It holds water, and allows a river to be released more slowly,' he said. 
'It keeps the rivers flowing. In the dry season it keeps the streams 
trickling. It gives time for the water to recharge the aquifer and keeps 
the water table up.'

Without this sponge function, rivers flow faster and carry off valuable 
nutrients, soil and organic matter from up-stream. Not only is this an 
economic waste, but the nutrients can damage lakes and kill fish by 
promoting an explosive growth of algae and reducing the oxygen at deeper 
levels - a process known as eutrophication.

The effects of neglecting wetlands can be seen in the world's largest 
tropical lake, Lake Victoria, which is bordered by Uganda, Tanzania and 
Kenya, and is a source of livelihood, food and employment for more than 30 
million people.

The once-astonishing diversity of fish species in the lake has been sadly 
depleted not only by the introduction of aggressive non-native species, but 
also because of the run-off of pollution and silt from the catchment.

Protection of the lake's environment was one of the reasons that prompted 
the Ugandan government to adopt a national wetlands policy and enshrine it 
in the constitution.

Swamps occupy about 13% of Uganda's territory, and used to cover a much 
greater area, including the land around the capital, Kampala. But a 
frustrated wetland is always a potential flood, and the urban sprawl and 
industries that surround Kampala are prone to frequent inundation as nature 
reasserts its rights.

The ensuing pollution and water stagnation clearly are sources of disease, 
but Prof. Denny said this is the result of a poorly managed environment and 
human pressure.

'The classic word is that wetlands are wastelands,' he said. 'I can think 
of nothing further from the truth. If water and wetlands systems are well 
managed, then health issues are not as serious as one might believe.

'Disease usually comes from poorly managed systems in which human beings 
themselves have changed the balance of nature. In a naturally functioning 
system with good biological diversity, you are not likely to have many 
mosquitoes because of the amount of fish, insects and birds that eat the 
larvae.'

Prof. Denny,  who  teaches  mid-career  water professionals at  the 
UNESCO-IHE Institute for Water Education at Delft, the Netherlands, said 
wetlands act as a natural purification system if they are allowed to do 
their job.

Seeded with fast-growing papyrus, which has many economic applications, the 
marshes not only filter out the impurities but recycle nutrients as well. 
This produces food for the invertebrates, which in turn provide nourishment 
for fish and birds.

'If you have more diversity, there is a greater chance that the people who 
live in those systems can have a sustainable way of life,' he said. 
Riparian people can ensure a better supply of fish by helping nature 
through digging ponds called 'fingerponds' at the fringes of the wetlands 
where fish collect. The ponds remain flooded in the dry season: the fish 
are fed on domestic waste and can grow fat.

Even industrialised countries, which have exported their dam- and 
canal-building technologies into the developed world, are starting to undo 
some of the hard engineering of rivers and lakes and allow water to occupy 
natural flood plains with beneficial effects for the people, the 
environment, for biological diversity and for the underground aquifers.

It is even possible to create small artificial wetlands to treat the sewage 
output of a village or clean the effluent from conventional sewage plants, 
which in Africa frequently fail to function because of electricity cuts and 
poor maintenance.

Such artificial swamps are odour-free, Prof. Denny said, and the water that 
comes out of the end is clean, although enough nutrients can be left in to 
keep fishes happy and to use in agriculture.

In New York's Jamaica Bay, which has had every conceivable pollutant dumped 
into it over decades, and is partly bisected by the runway at John F 
Kennedy airport, the cleanliness of the water is a source of wonder to 
environmental scientists. Despite such resilience, the 10,000 acres of 
wetlands, forests and beaches have shrunk by about half their original size 
because of a combination of man-made and natural causes.

Engineers have belatedly come to appreciate that the once-neglected bay, 
like the disappearing mangrove swamps of Asia, may play an important role 
in calming the energy of the sea and protecting the mainland as climate 
change brings with it the threat of rising ocean levels. From New York to 
Venice, and Indonesia to Uganda, environmentalists are increasingly finding 
out that bogs and swamps are not insalubrious wastelands, but waterlogged 
wealth and friends of nature and of mankind. - Third World Network Features.

-ends-

About the writer: Barry James writes for the UNESCO Courier. The above 
article appeared in UNESCO-IHE (Institute for Water Education) Update 
(January 2004).

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