New research from the University of Brighton could revolutionise the way the EU legislate water quality. The research led by the University’s Dr Gary Bilotta was funded jointly by Aquaread and the Engineering and Physical Research Council.The purpose of the research was to improve the European water quality guidelines and has discovered that high levels of suspended particulate matter (SPM) are actually essential to the health of some types of freshwater ecosystems. These findings could lead to changes in the way that water quality is managed to protect aquatic wildlife.
Suspended particulate matter refers to nano-scale to sand-size pieces of eroded soil and organic matter that are found naturally in freshwater bodies of water. A high level of SPM can give the water a dirty appearance. SPM is one of the most common causes of impaired water quality around the world. The researchers studied 638 healthy stream and river sites across the UK, which represent 42 different types of freshwater ecosystems. They also investigated the environmental factors that determine the levels of SPM in these healthy ecosystems.
The research found that SPM levels varied significantly (up to 15x) between the ecosystems tested. Only 1 ecosystem had average concentrations that exceeded the current limit but some ecosystems had very low levels of SPM. The study shows that freshwater ecosystems differ in their tolerance of SPM so the water quality guidelines should be altered to reflect this. In some ecosystems SPM actually provides a food source to organisms and represents an important component of the habitat for organisms. Conversely, in other ecosystems SPM can harm organisms, even at relatively low concentrations. The research suggests that there should be different guidelines for SPM concentration for different types of freshwater ecosystems.
Current EU legislation is in place to minimise SPM and tightly control pollution caused by human activities. This legislation means that landowners and water users can be fined for being found to contribute to the failure of a water body to meet defined quality guidelines. The study has shown that not only is the background concentration of SPM within a water body mainly decided by local environmental factors, that can be predicted using an analysis model, but ecosystems require different levels of SPM to thrive. Current legislation could actually result in a landowner being fined unnecessarily.
The research has been published in Water Research, an international academic journal, and has already received attention from European policy makers. The findings have potentially big implications for land use and water quality management across the continent.