Wetland habitats take many forms, from upland peat bogs through to valley mires, floodplain meadows and vast reedbeds. Whether fed by rain or groundwater, these wet habitats all need a water supply to create the conditions that keep their soils, vegetation and resident species happy and healthy. Our two counties have many important wetland habitats including rare chalk streams. Many of our nature reserves reflect this, being wetland sites which are home to a diverse range of wildlife, including Blashford Lakes Nature Reserves, Fishlake Meadows Nature Reserve, Pewit Island Nature Reserve and Newchurch Moors Nature Reserve. 

In the UK we have lost a startling 90% of our former wetlands, often by draining them to make way for agriculture, development, forestry and other land uses.

Here are just some of the essential services that wetlands provide:

Flood protection

Natural wetlands provide flood protection by slowing down and storing flood flows. Rough, tussocky sites like Devon’s Culm grasslands are extremely good at holding on to water – with research showing that, in comparison, 11 times more water leaves intensively managed grasslands during storms, placing communities downstream at risk.

Coastal reedbeds and saltmarshes buffer us from storm surges, and floodplains – when not built over – hold the excess flows from our river systems.

The use of these natural protections is termed ‘Natural Flood Management’, and can involve anything from small-scale features that mimic nature (like ‘leaky dams’ or flood storage ponds, which hold back water in high flows and allow it to drain through later, once the risk of flooding has passed) to vast habitat recreation, such as on low-lying farmland on the Essex coast at Abbotts Hall, where the failing sea wall was purposely breached to create new marshland, now teeming with migratory birds, and a network of creeks that form a valuable nursery for bass, herring and other fish.   

Some of places the Trust manage including Winnall Moors Nature Reserve in Winchester, help alleviate flooding in towns by holding back water in their wetland habitats and slowing the flow of rivers. 

Carbon storage

Wetlands are important stores of carbon – when wetland plants die, rather than decomposing and releasing their carbon into the atmosphere, they become buried in the sediment making up peatland soils. These soils, which accumulate over thousands of years, hold vast amounts of carbon and are our biggest carbon store on land. If allowed to dry out, they release CO₂and rather than mitigating climate change contribute to it. Researchers have calculated that if all of the carbon held in peatlands globally were released, it would raise atmospheric CO₂ concentrations by 75%, with catastrophic consequences for global climate.

Peatland rewetting prevents the release of this locked-up carbon, so is a key tool in our fight against climate change. Restoring fens and bogs will also provide crucial habitat for insect-eating plants, wading birds like dunlin, hen harriers, and numerous insect species, and where full-scale habitat restoration isn’t feasible, testing ways in which peatlands like the fens can be more sustainably farmed is a key part of the solution too. Other wetland habitats also suck up carbon, for example on saltmarsh, one study suggests that as new layers of sediment form they can store carbon nearly four times faster than trees!

Wetland sites like Tipner West contain mudflats that store huge amounts of carbon, as well as being a safe nursery for marine creatures like bass and many invertebrates and micro-ogranisms which make the site so attractive to other wildlife.

Marine Specialist Tim Ferrero puts it this way:

‘‘Mudflats might not sound exciting but are actually a biological powerhouse, a key habitat providing essential services for countless species, supporting biodiversity and supporting us. As mudflats build up, they capture all manner of organic material from the water column which feeds bacteria, fungi and microscopic algae that teem within the mud. Millions of small invertebrates burrow into the mud or forage on its surface, some of these animals, for example sea bass, clams and oysters, can even feed us!

The food produced by mudflats goes directly to feeding the many wading and other bird species which rely on them such as Brent Geese, Godwit and Plover species. Mudflats also have a vital role in storing carbon and processing excessive organic material, sewage and nitrate fertilisers in agricultural runoff, helping to improve the water quality in our stressed estuaries and the wider Solent.’’

Unfortunately Tipner is being threatened by development, so make sure to sign our petition telling Portsmouth City Council to scrap their plans. 

Wellbeing

Wetlands are also good for mind, body and soul! The natural environment is proven to be important for both physical and mental health, and the NHS are now piloting ‘green’ social prescribing to help patients with issues like depression, anxiety, obesity, and heart disease. But our fascination with water and wetlands suggests that wet habitats might be especially important in this nature-health interaction – ongoing research is looking at how we might use wetlands to achieve health outcomes faster and more effectively in future.

For all these reasons and more, our wetland habitats are a treasured part of the UK landscape, crucial for wildlife and for people. Together they form part of a dynamic and connected waterscape that, with a little help, can continue to support a huge and unique diversity of wildlife.

Hampshire & Isle of Wight Wildlife Trust are working to protect and restore our damaged wetlands as part of our vision to see 30% of our land and seas made wilder and 1 in 4 people connecting with and taking action for nature by 2030.

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