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How can we mitigate the increasing problems of pollution and lost biodiversity in our rivers, streams and ponds caused by pesticides, phosphorous, diffuse pollution from agriculture and even the seeping of nutrients from septic tanks and small sewage treatment works?
The Water Friendly Farming Report 2014, by the Freshwater Habitats Trust and the Game & Wildlife Conservation Trust, highlights the results of the four-year Water Friendly Farming Project, which for the first time identifies the specific habitat creation needed to prevent the loss of freshwater biodiversity at the landscape scale.
Results of the research show that the creation of new wildlife ponds is vital in helping to reverse a decline of aquatic plants. The researchers identified that 80% of all freshwater plants are found in ponds and therefore make a very large contribution to protecting freshwater biodiversity. However, there has been a marked decline in both the number of ponds and their quality across England and Wales between 1998 and 2007. But despite being established for under a year, the newly created ponds in the project played a crucial role in offsetting the apparent decline of aquatic plants in the wider landscape within a very short time-scale.
Grass buffer strips along streams and ditches and implemented under Environment Stewardship Schemes also proved highly effective in protecting freshwater from pollution by halving the movement of sediment from land to water. Combining computer modelling and field monitoring data, the project discovered that without the protection of grass buffer strips alongside rivers and streams at least 890 tonnes of sediment from the land ended up in the freshwater. Computer modelling indicated that the buffer strips had reduced this to under 400 tonnes.
Professor Chris Stoate, from the Game & Wildlife Conservation Trust’s Allerton Project at Loddington in Leicestershire, explains, “Given that many grass buffer strips are likely to be lost as Stewardship agreements expire over the next few years, the implications for water quality in the future could be worrying.”
The aim of the Water Friendly Farming Project is to test the effectiveness of landscape-wide measures like constructed wetlands, stream fencing, flood storage ponds and the creation of new freshwater habitats, designed to reduce the unintended effects of agriculture on the freshwater environment. Crucially, by creating habitats in mainly unproductive parts of farms, the project has minimised any impact on food production or farm profitability.
Dr Jeremy Biggs of the Freshwater Habitats Trust said, “Currently many millions of pounds are spent on measures aimed at protecting our freshwaters from the impacts of land-use. However, there is remarkably little evidence available to assess whether they are actually protecting freshwater biodiversity or reducing pollution.
“This is important, because globally there are concerns that freshwater biodiversity is declining seriously, and in the UK many freshwater species that have been lost from a large part of the landscape and are still declining.”
As well as making new ponds to help protect aquatic wildlife, the project is investigating whether mitigation measures can reduce the loss of nutrients, sediments and pesticides from the land to reduce water pollution and decrease the rate of run-off to help reduce flooding further downstream.
The project is also investigating the effect of village sewage treatment works, septic tanks and run-off from roads. Tributaries with sewage treatment works in them have consistently higher phosphorus concentrations than those in purely agricultural catchments, and peaks in phosphorus concentration at the base of each study catchment are reached in later summer before runoff from agricultural land occurs.
Professor Stoate, said, “This project is extremely significant because it is providing some of the first evidence that in a commercially viable farming system it is possible to protect life in freshwater. Farming has many competing demands to fulfil and with the need to produce more crops, it is essential that we can do this and still protect the natural environment.”