Swamps and bogs don’t tend to get the same level of attention as rainforests or coral reefs. However, wetlands are one of the most biodiverse and productive ecosystems on the planet and they are being lost at an alarming rate. World Wetlands Day on February 2nd aims to raise global awareness about the vital role of these habitats, and in 2022 the focus is a call to action to save and restore the world’s wetlands.
What are wetlands?
Wetland habitats take many forms including peatlands, floodplain meadows, estuaries, reedbeds and marshes, extending across inland and coastal zones. They are either permanently or seasonally inundated with water, and range in size from the Pantanal floodplains of South America at over 180,000km², to your back garden pond. Different wetland habitat types often combine into complex ecosystems, and they support an incredible diversity of plant and animal species.
Why are wetlands important?
BIODIVERSITY – These amazing areas are some of our most valuable ecosystems, with 40% of the world’s wildlife relying on them, including half of all bird species and two thirds of all fish species. Rich in plant life and packed with insects, they are home to many of the UK’s protected species including otter, water vole, great crested newt, European eel, and white-clawed crayfish. They are a great place to see a range of birds such as lapwing, curlew, snipe, and marsh harrier.
CARBON STORAGE – Wetlands are important stores of carbon. Wetland plants absorb carbon dioxide and when they die and partially decompose, they form peatland soils. Over thousands of years these soils accumulate vast amounts of carbon, holding around one third of total carbon in soils and more than is held in all living vegetation combined. When peatlands are drained or extracted for horticultural use, they release CO₂ into the atmosphere with implications for climate change. Emissions from peatland currently contribute around 3.5% of all human-caused greenhouse gas emissions globally. If all carbon currently stored in peatland was released, it would raise atmospheric CO₂ by 75%, with disastrous results. Rewetting and restoration of peatlands prevents the release of this stored carbon, while providing important habitat for plant and animal species.
FLOOD CONTROL – Wetland habitats act as a buffer to store and slow rainwater runoff and flood flows, gradually releasing it back into the system. River floodplains hold excess flows from our river systems and saltmarshes on the coast absorb wave energy. When wetlands are drained or floodplains used for development, the risk of flooding downriver increases. ‘Natural flood management’ schemes are used to recreate natural processes to reduce flooding or coastal erosion, such as restoring bends in rivers or creating new salt marshes. This not only reduces flood risk but can help restore habitats and improve water quality.
CLEAN WATER – One of the valuable services provided by wetlands is the protection of downstream watercourses from sediment and pollutants, through physical, chemical, and biological processes. Water flow slows as it enters a wetland, allowing suspended particles to drop out of the water column and into the ground layer. A slower water flow improves water chemistry, allowing time for bacteria to naturally convert toxic nutrients into less harmful forms. Nutrients from sewage, agricultural run-off and other sources are used by growing plants and soil microorganisms. In fact, wetlands are so effective at this filtering process that they are being planted and preserved to replace traditional water treatment plants at a much lower cost; New York City found that it could save $3-8 billion in new water treatment plants by buying and conserving $1.5 billion in wetlands around its upstate reservoirs.
WELLBEING – The natural environment is increasingly understood to have a significant impact on our physical and mental health. Research shows that even short periods of contact with nature can improve conditions such as anxiety, stress and depression, and it appears that water and wetlands may be especially important in these nature/health interactions. Research by the Mental Health Foundation found that being near lakes, rivers and the sea was rated the highest by people in terms of having a positive impact on their mental health.
Why are wetlands at risk?
Despite the essential role of wetlands for people and planet, estimates show that at least 64% of the world’s wetlands have disappeared since 1900, disappearing three times faster than forests. In the UK we’ve lost a staggering 90% of our wetland habitats in the last 100 years and over 10% of our freshwater and wetland species are threatened with extinction.
The reasons for this dramatic loss include unsustainable farming and development practices, urbanisation and water abstraction. Species are affected by pollution from rural and urban areas, modification of rivers and other wetlands and invasive non-native species. Raised bogs have been destroyed or degraded through industrial peat-cutting for fuel or use in compost, and in some places this continues.
How do we protect and restore wetlands?
World Wetlands Day marks the anniversary of the Ramsar Convention on Wetlands in 1971. Under this convention, wetlands of international importance are designated as protected Ramsar sites. The UK currently has more Ramsar sites than any other nation with 175 designated sites, all with commitments for conservation objectives. UK wetland sites often also fall under other levels of protection such as Sites of Special Scientific Interest (SSSIs), Priority Habitats, or Biodiversity Action Plans.
In recent decades, after years of decline, wetlands are making a comeback. Nature conservation organisations, water companies, landowners, farmers and local communities are recognising the value that these habitats hold. Restoration and creation projects have been implemented across the UK, such as the award-winning Anglesey and Llŷn Fens LIFE Project or the Wallasea Island Wild Coast Project. The Wildlife Trusts are currently running trials to reintroduce beavers, which would once have played a crucial role as ’ecosystem engineers’ creating diverse and dynamic wetland systems through coppicing, damming, and digging ‘beaver canal’ systems.
What can we do?
One of the most effective ways you can help wildlife in your garden is to create your own wetland area. A garden pond will provide shelter, breeding grounds, food and drinking water for mammals, birds, amphibians, and invertebrates. Taking time to design your pond to incorporate features to attract a wide range of species will really maximise the benefits. If a pond is not suitable, if young children use the garden for example, using a damp area to create a bog garden can be a great way to incorporate valuable habitat. Frogs, toads, or grass snakes may be attracted to the area along with dragonflies, butterflies and other insects.
You can visit, support, or volunteer for your local wetlands by looking for local reserves run by charities such as the Wildfowl and Wetland Trust (WWT), the Royal Society for the Protection of Birds (RSPB), the Wildlife Trusts and the National Trust.
Our wetland habitats are a vital part of the UK landscape, essential for wildlife and for people. They form part of a dynamic and interconnected system that, with a little help, can continue to sustain a vast and unique diversity of wildlife.
Jenny O’Neill, Assistant Ecologist
Davidson, N. C. (2014). How much wetland has the world lost? Long-term and recent trends in global wetland area. Marine and Freshwater Research, 65(10), 934-941.
Evans, C., Artz, R., Moxley, J., Smyth, M-A., Taylor, E., Archer, N., Burden, A., Williamson, J., Donnelly, D., Thomson, A., Buys, G., Malcolm, H., Wilson, D., Renou-Wilson, F., Potts J. (2017). Implementation of an emission inventory for UK peatlands. Report to the Department for Business, Energy and Industrial Strategy, Centre for Ecology and Hydrology, Bangor.88pp.
WWF and the Swiss Agency for the Environment, Forests and Landscape (2004) – The Economic Values of the World’s Wetlands