Approximately 50 % Of World’s Wetlands Lost During The 20th Century
By Marianne de Nazareth
18 October, 2012
How many of us have ever bothered about the wetlands of the world? To the common man a wetland is just a waste of ‘good’ land, and we never understood what the real use of wetlands are and how important it is to protect them. Unfortunately we humans sit up and take notice of issues with our planet only if we are affected by a problem and after we have destroyed a lot of the ecosystem. Now with the rationing of fresh water in most of our metropolises across India, we have come to realise how important it is to save our wetlands, carefully use our ground water and strongly protect our lakes and water bodies.
The world according to the new TEEB report ( The Economics of Ecosystems and Biodiversity) released at the 11th meeting of the Conference of the Parties to the Convention for Biological Diversity (COP11) in Hyderabad needs to realise the vital economic and environmental role of wetlands, to halt further degradation and loss.
Countries across the world need to realise the key role that rapidly diminishing wetlands play in supporting human life and biodiversity. Water security is widely regarded as one the key natural resource challenges currently facing the world. Human drivers of ecosystem change, including destructive extractive industries, unsustainable agriculture and poorly managed urban expansion, are posing a threat to global freshwater biodiversity and water security for 80 per cent of the world’s population.
Global and local water cycles are strongly dependent on healthy and productive wetlands, which provide clean drinking water, irrigation for agriculture, and flood regulation, as well as supporting biodiversity and propping up industries such as fisheries and tourism in many countries. Yet, despite the high value of these ecosystem services, wetlands continue to be degraded or lost at an alarming pace. Half of the world’s wetlands were lost during the twentieth century – due mainly to factors such as intensive agriculture, unsustainable water extraction for domestic and industrial use, urbanization, infrastructure development and pollution. The continuing degradation of wetlands is resulting in significant economic burdens on communities, countries and businesses.
Inland wetlands cover at least 9.5 million km (about 6.5 per cent of the Earth’s land surface), while inland and coastal wetlands together cover a minimum of 12.8 million km. Between 1900 and 2003, the world lost an estimated 50 per cent of its wetlands, while recent coastal wetland loss in some places, notably East Asia, has been up to 1.6 per cent a year. This has led to situations such as the 20 per cent loss of mangrove forest coverage since 1980.
The main pressures on wetlands come from: Habitat loss, for example through wetland drainage for agriculture or infrastructure developments, driven by population growth and urbanization;
Over-exploitation, for example the unsustainable harvesting of fish; Excessive water withdrawals for use in, for example, irrigated agriculture; Nutrient loading from fertilizer use and urban waste water, which can lead to eutrophication – the excessive growth of algae that deprives other species of enough oxygen and can create dead zones; Climate change, which can alter ecosystem conditions through rising temperatures; Pollution, remarkably through extractive industries, invasive species and siltation.
Such pressures threaten wetlands’ natural infrastructure, which delivers a wider range of services and benefits than corresponding man-made infrastructure at a lower cost. Wetlands are a key factor in the global water cycle and in regulating local water availability and quality. They contribute to water purification, de-nitrification and detoxification, as well as to nutrient cycling, sediment transfer, and nutrient retention and exports. Wetlands can also provide waste water treatment and protection against coastal and river flooding.
For example, The Catskill / Delaware watershed provides about 90 per cent of the water used by New York City citizens. In 1997, a study showed that building a new water treatment plant would cost between US$6 and US$8 billion, whereas ensuring good water quality through measures to reduce pollution in the watershed would only cost US$1.5 billion. This study led to programmes to promote the sustainability of the watershed.
Wetlands also play a key role in the provision of food, and habitats and nurseries for fisheries. One example is the Amu Darya delta in Uzbekistan where Intensification and expansion of irrigation activities left only 10 per cent of the original wetlands. Yet a pilot restoration project initiated in the delta, with the support of community, government and donors which has led to increased incomes, more cattle, more hay production for use and sale, and an increase in fish consumption of 15 kilogrammes per week per family.
Wetlands can also be an important tourism and recreation sites and support local employment. For example In the Ibera Marshes in Argentina, conservation-based tourism activities have revived the economy of Colonia Carlos Pellegrini, near the Ramsar Site “Lagunas y Esteros del Iberá”, creating new jobs and allowing local inhabitants stay employed in the town rather than migrate to cities to look for work. Around 90 per cent of the population now works in the tourism sector. In order to favour local employment, the site managers provide local rangers and guides with training on working with guiding tourists. In addition, local communities receive support to establish municipal nature trails.
Biodiversity Wetlands are some of the most important biologically diverse areas in the world and provide essential habitats for many species. Coral reefs, peatlands, freshwater lakes, waterbirds, amphibians and wetland-dependent mammals such as hippopotamus, manatees and river dolphins are among those examples of biodiversity covered by the global Ramsar Convention network of “Wetlands of International Importance”, which comprises over 2,000 sites covering over 1.9 million km.
Wetlands also provide climate regulation, climate mitigation and adaptation, and carbon storage – for example in peatlands, mangroves and tidal marshes. Peatlands cover 3 per cent of the world’s land surface, about 400 million hectares (4 million km2), of which 50 million hectares are being drained and degraded, producing the equivalent of 6 per cent of all global Carbon Dioxide emissions. While vegetative wetlands occupy only 2 per cent of seabed area, they represent 50 per cent of carbon transfer from oceans to sediments, often referred to as ‘Coastal Blue Carbon’.
National and international policy makers should: Integrate the values of water and wetlands into decision making – for policies, regulation and land-use planning, incentives and investment, and enforcement; Regulate to protect wetlands from pressures that do not lead to improvements in public goods and overall societal benefits; Regulate to ensure that wetland ecosystem services options and benefits are fully considered as solutions to land- and water-use management objectives and development; Commit to and develop improved measurement and address knowledge gaps – using biodiversity and ecosystem services indicators and environmental accounts.
“Policies and decisions often do not take into account the many services that wetlands provide – thus leading to the rapid degradation and loss of wetlands globally,” said UN Under-Secretary General and UN Environment Programme Executive Director Achim Steiner.
“There is an urgent need to put wetlands and water-related ecosystem services at the heart of water management in order to meet the social, economic and environmental needs of a global population predicted to reach 9 billion by 2050,” he added.
“In 2008 the world’s governments at the Ramsar Convention’s 10th Conference of Parties stressed that for water management carrying on ‘business as usual’ is no longer an option”, said the Ramsar Convention’s Deputy Secretary General, Nick Davidson.
“This report tells us bluntly just how much more important than generally realized are our coastal and inland wetlands: for the huge value of the benefits they provide to everyone, particularly in continuing to deliver natural solutions for water - in the right quantity and quality, where and when we need it. If we continue to undervalue wetlands in our decisions for economic growth, we do at our increasing peril for people’s livelihoods and the world’s economies,” he added.
(Marianne de Nazareth is Independent media professional and adjunct faculty St. Joseph’s College and COMMITS, Bangalore)
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