The world’s wetlands are increasingly at risk from pollution, threatening the drinking water supply for millions and reducing biodiversity. But at the same time, wetlands can also provide the solution to the problem.
Wetlands are particularly susceptible to pollution. They’re often found in the lower reaches of water courses, or are fed by numerous streams and waterways, so they have the potential to “receive and collect” pollution from over a wide area. This pollution can then build up and have a massive impact on the health of a wetland.
Fertilisers and pesticides used in modern day intensive farming pose one of the biggest threats to wetlands. These chemicals, along with toxins like mercury from polluting factories, can affect the health and reproduction of plants and animals and severely reduce biodiversity.
In the UK, pollution from a specific location like an overflow pipe or a factory is increasingly coming under control. But in less developed countries, where there is less legislation, this type of “point-source” pollution continues to be of particular concern.
Plastics are also a major source of pollution for wetlands, particularly in coastal areas. 8–12 million tonnes of plastic finds its way into our oceans each year. Yet it has been projected that virgin plastics production will have risen by 40% by 2030.
As well as being threatened by pollution, wetlands also have an important role in addressing it. They can act as natural filters, helping to remove pollutants from the water. In fact they have the potential to remove up to 60% of metals, trap and retain up to 90% of sediment runoff and eliminate up to 90% of nitrogen.