Wetlands are exceptionally biodiverse habitats, with thousands of animal and plant species around the globe being heavily dependent on them. In fact, it is believed that 40% of all the world’s species are dependent in some way on the continued existence of wetland habitats. With the term wetland meaning any habitat that is seasonally, or permanently, saturated by water, wetlands are also exceptionally diverse in character with a great variety of different types found around the world. These can range from reedbeds, swamps, peat bogs, mangrove forests, saltmarsh and fen to name but a few. Each of these wetland types supports a unique suite of species, some of which are entirely endemic to that particularly habitat; for example, the famous booming bittern only breeds in the reedbeds of Europe and Asia.

Wetlands are also a highly effective means of mitigating and preventing flooding. By acting like a sponge in the landscape, wetlands can absorb vast amounts of excess rain fall, greatly reducing the amount that flows into rivers. They also play a vital role in the prevention of coastal flooding. Saline wetland habitats such as mangrove forests and saltmarsh help to hold back sea water and absorb the sea’s power in events such as storm surges. Across the UK, saltmarshes are being actively restored in many of our estuaries to reap these benefits. The loss of much of our wetlands in the UK and across the world is undeniably a contributing factor in the increase of damaging flood events in recent years. With climate change likely to increase rainfall and freak weather events in many parts of the world, restoring these natural flood barriers will be a great asset in protecting human populations as well as increasing biodiversity.

Undoubtedly the most significant of the many assets that wetlands provide in our fight against climate change is that they are the most effective carbon sinks of any habitat on Earth. For instance, despite covering a far smaller percentage of the Earth’s surface, peat bogs hold twice as much carbon as all the world’s forests combined. The reason wetlands are capable of storing so much carbon is that wetland plants absorb huge amounts of carbon dioxide via photosynthesis and because the oxygen poor soils found in wetlands such as peat bogs mean that dead plant matter biodegrades very slowly, causing the accumulation of huge amounts of highly carbon rich soils over thousands of years. But this seemingly magical ability to store carbon is also a double-edged sword; as wetlands around the world are drained for agriculture and other human activities, and as ancient wetlands in polar regions begin to melt due to global warming, huge quantities of this locked-up carbon, as well as the extremely potent greenhouse gas methane, are released into the Earth’s atmosphere, thus accelerating climate change even further. This gives us further cause to preserve and restore our precious wetland habitats.

Another of the many ecosystem services that wetlands provide, which humans and wildlife hugely benefit from, is water purification. As water enters a wetland via rain, run-off or ground water, wetland animals and plants, as well as microorganisms, feed on potentially harmful nutrients and convert them into other forms via various biological processes. Another way in which wetland habitats improve water quality is via filtration. A wetland habitat that is excellent at this, and as a result is being restored across the UK, are beaver ponds. A watercourse is greatly slowed down as it flows through a beaver pond and many large pollutant particles and sediments are deposited on the bed of the pond as the river loses momentum. As well as this, the beaver dam itself also filters out many of these large particles, preventing them from flowing down stream. Trials across the UK have proven that beavers living at the top of river catchments greatly improve water quality directly downstream.  

Despite us now knowing the immense benefits that wetlands provide to wildlife, the broader environment and people, humans are having a very damaging effect on wetlands globally. The UK has witnessed some of the most devastating losses of wetland habitats anywhere in the world. In the middle ages, entire regions of Britain such as the Fens in East Anglia and the Somerset Levels were vast, almost uninhabitable labyrinths of fen, marsh and reedbed, but sadly only small fragments now remain. In the last 100 years alone, the UK has lost 90% of its wetland habitats, mainly as a result of drainage for agriculture and development. This has resulted in devastating declines of iconic species such as curlew and water voles. Globally, the situation is not much better. It is now thought that globally we have lost 87% of the world’s wetland habitats as a result of human activities, with much of our remaining wetlands still under threat. Despite this bleak picture, conservationists around the world are working tirelessly to protect what remains but also restore what has been lost. Locally, Herefordshire Wildlife Trust have been involved in ambitious wetland creation projects at Bodenham Lake and Oak Tree Farm Nature Reserves. There are many other wetland creation projects occurring across the UK. Perhaps the most exciting is the Great Fen project, being led by Bedfordshire, Cambridgeshire and Northamptonshire Wildlife Trust, which aims to eventually create 14 square miles of continuous fenland habitat in East Anglia.