- Review of Water Framework Directive points to increased diversity of invertebrates, fish, plants, algae
- Cunliffe report urges Government to consider scientists’ proposals including a biodiversity audit
The system for assessing the health of England’s rivers states just 14% are in good ecological health but an independent report for Defra says this masks improvements in freshwater biodiversity – and has proposed an alternative monitoring standard.
A team of scientists, led by the UK Centre for Ecology & Hydrology (UKCEH), carried out a review of the ecological status assessments of the Water Framework Directive (WFD), and criticised its ‘one out, all out’ approach. This prevents a waterbody being awarded ‘good ecological status’ if concentrations of a single element, such as a chemical, are above the threshold – even though it also receives a separate chemical status.
The Cunliffe report, published on 21 July, said the UK Government should consider the review’s recommendations, which include a proposed regular biodiversity audit that could be introduced fairly quickly and run alongside the WFD.
A variety of chemical pollutants from agriculture, industry, wastewater and roads find their way into rivers, lakes and other waterbodies. But the authors of the review point out that analyses of a wealth of Environment Agency sampling data show there have been important improvements in the species richness of invertebrates, plants, fish and benthic (bottom-dwelling) algae in rivers over recent decades.
The scientists say a biodiversity audit would more clearly reveal the status of different species at any given location, informing local people. It would be supported by statistical analysis of associated monitoring data on chemical concentrations, habitat quality, water temperature and flow to clearly identify what elements might be suppressing biodiversity.
Providing a clearer picture
While the WFD assessments are revealed every six years, the statistical analysis would be carried out every year based on the Environment Agency sampling data. This would provide a clearer and simpler picture of how human activities are affecting wildlife, thereby supporting what the scientists say should be the desired outcome – improvements in biodiversity.
Previous UKCEH analyses of Environment Agency data have shown increases in diversity of freshwater invertebrates correlate with reductions in metal pollution and improvements in wastewater treatment over the last 30 years.
Professor Andrew Johnson, an environmental scientist at UKCEH, who led the review. said: “There has been no increase in the number of waterbodies achieving good ecological status, which might appear to imply there have been no improvements for wildlife since full reporting for the Water Framework Directive began in 2009. This is not the case, and the disconnect between the scientific evidence and the ecological status results brings into question the value of the whole process.
“For example, the WFD would direct us to put a lot more money into further reducing phosphate concentrations, yet according to our statistical analysis, this may be less beneficial to overall biodiversity than tackling key metal contaminants.”
Change in focus
The review authors, from UKCEH, The James Hutton Institute and AtkinsRéalis, point out that their recommendations would not require any radical change to the current monitoring arrangements. Instead, it would be a change in focus to reporting on biodiversity as the endpoint and the introduction of statistical methods to establish what really holds back further improvements.
The scientists envisage that, in time, a combination of the proposed surface waterbody biodiversity audit, as well as chemical quality and human health standards could replace the WFD classification. The WFD, which applies to rivers, lakes, canals, estuaries and coastal waters, was introduced by the EU and retained by the UK after Brexit. It requires governments to aim to achieve at least good ecological status for all surface water bodies by 2027, but it is highly likely that this target will be missed.
In the last classifications in 2019, just 16% of all water bodies assessed in England (including 14% of rivers) had good ecological status. In Wales, 40% achieved this standard in interim classifications in 2024.
Healthy improvement
While there is widespread concern about the state of our rivers, Professor Johnson says their ecological health is generally much better than it was in the 1980s. While it is difficult to make like-for-like comparisons, he estimates that if the proposed biodiversity audit were introduced, over 54% of rivers in England would achieve at least good ecological status, as opposed to 14% currently.
The Independent Water Commission, led by Sir Jon Cunliffe, has recommended reforms to the regulations and scope of the WFD in the UK, and says the Government should consider the UKCEH-led review on how to reform the good ecological status metric.
The UKCEH-led review of the WFD is likely to form part of the evidence base for any changes to the methods used to measure and report on the water environment. It is available on the Defra website.
-Ends -
Media enquiries
For an interview with a review author or further information, please contact Simon Williams, Media Relations Officer at UKCEH, via simwil@ceh.ac.uk or +44 (0)7920 295384.
Notes to Editors
Report information
The review is entitled: Review of the Classification Framework for Ecological Status/Potential under the Water Environment (Water Framework Directive) England and Wales Regulations – WT15168. It was funded by Defra.
About the UK Centre for Ecology & Hydrology (UKCEH)
The UK Centre for Ecology & Hydrology (UKCEH) is a leading independent research institute dedicated to understanding and transforming how we interact with the natural world.
With over 600 researchers, we tackle the urgent environmental challenges of our time, such as climate change and biodiversity loss. Our evidence-based insights empower governments, businesses and communities to make informed decisions, shaping a future where both nature and people thrive.
ceh.ac.uk / BlueSky: @ukceh.bsky.social / LinkedIn: UK Centre for Ecology & Hydrology