Wetlands supply us with an abundance of food and useful stuff, but this natural wealth could also be their downfall
David Reay, The Times 1 Apr 10;
• If ever there were a fitting ecological term, it is wetland. For these vast tracts of marshes, swamps, bogs, fens, coasts, reefs and flood plains are exactly that — a confluence of water and land. Covering 4 to 6 per cent of the world’s surface, they form where water cannot drain away. Even London has some.
• The 15,000sq km Bangweulu wetlands in Zambia are an ever expanding and contracting wilderness, flooding and receding in time with seasonal rains. David Livingstone, the missionary, discovered them in 1868. Returning five years later, he died there, exhausted and malarious.
• Freshwater areas are home to more than 40 per cent of all the world’s species. Nearly two thirds of the world’s fish harvest is plucked from wetlands and migrating birds depend on them for refuge. They also sustain up to 400 million people, making them in effect nature’s supermarket …
• So first, the fruit and veg section. Oil palms, one of the world’s most important sources of edible oil, biofuel and soap, occupy millions of acres of swampy plantations in Malaysia and Indonesia. Cranberries, which grow in marshes, are a $1.5 billion industry in the US.
• And so through to groceries. More than half the world’s population relies on one staple food — rice. Although many paddy fields are now man-made, the wild strain of rice first grew in swamps. Sago, a starchy cereal, also has its roots in South-East Asian flood plains.
• Which brings us to the meat and fish counter. Saltwater wetlands are a haven for fish and shellfish. In 2008, nearly half a billion Scottish farmed salmon meals were eaten, with most hatcheries relying on water from wetlands.
• So what about household goods? Willow trees are synonymous with river banks, and from them we derive aspirin, wicker and, of course, cricket bats. And forget bleach — wetlands act as natural sewage works.
• And now the DIY aisle. Reeds have been used for thousands of years as thatch, although cutting down wetland buffers is not always a good idea. The cost of replacing Malaysian coastal mangrove swamps — a natural storm and flood protection system — with concrete walls has been estimated at almost £200,000 per kilometre.
• Finally, let’s pull into the fuel station. Peat is a clean and efficient fuel when dried. And mangrove charcoal, highly prized for its long-lasting heat, provides income for communities from Thailand to the Caribbean.
• All these benefits mean that wetlands are in demand and thus in decline. More than half the world’s coverage has been destroyed in the past 100 years and they are now the most threatened ecosystem on Earth. The Convention on Wetlands of International Importance was adopted in 1971 and it protects 185 million hectares in 159 countries. But, as shown below, this is the tip of the iceberg.
