What are wetlands and why are they important?

Wetlands are a characteristic feature of many areas in the United Kingdom including the Humberhead Levels and The Fens. Wetlands usually form in glacially influenced areas and can be small and scattered features or cover extensive parts of the landscape.

Wetland habitat types vary from freshwater to coastal and marine, and include lakes, rivers, bogs and marshes but these valuable habitats are now under threat. Globally, there has been a massive reduction in the total area of wetland habitats. It has been estimated that approximately two-thirds of European wetlands that existed 100 years ago have been lost (Anon, 2004). It is also estimated that in the Roman period, as much as 25% of the British Isles were covered by vast wetland habitats, but in the 21st Century wetlands cover only 5% of the UK landscape (Rackman, 1986).

In many industrialised countries rivers have been straightened and deepened for navigation purposes and embanked to protect the surrounding areas against floods. This effectively isolates the floodplain from frequent flooding from the river and has enabled intensification of agriculture and urban development. Policies promoting the intensification of agriculture have been a primary driver for the drainage and loss of floodplain wetlands. Land drainage and ground water abstraction has further reduced the quality and extent of floodplain wetlands.

Whilst this massive reduction in wetland habitats has taken place, there has been an increasing realisation that wetland habitats play an important role in allowing the retention of high levels of biodiversity, and in limiting the impact of human activities on the environment.

There are also a large number of socio-economic arguments for maintaining biodiversity levels as wetland habitats can produce valuable resources and are important recreational areas. For example, a reduction in species richness due to decreased biodiversity may affect the potential use of wild plant derivatives in new drugs and other products, which destroys a potential source of income.