75% of British Rivers in Poor Ecological Health, Citizen Science Survey Finds

A large citizen science survey of rivers in Britain — the Great UK WaterBlitz Report — has found that 75 percent are ecologically unhealthy due to agricultural runoff and pollution from water companies.

Monitored by Earthwatch Europe volunteers, the survey found that waterways in the basin of the famed River Thames — as well as other rivers in the East Anglia and southeast regions of England — were in the worst shape, reported The Guardian. In those parts of the country, 89 percent were found to be in poor ecological health.

“The picture around London and the Thames river basin is particularly dire,” said Dr. Sasha Woods, Earthwatch Europe’s director of science and policy, as The Guardian reported.

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The worst water quality was found in the counties of Cambridgeshire, with 89 percent of rivers having unsatisfactory nutrient pollution levels, and Hertfordshire with 91 percent.

“Unsurprisingly, counties in the Thames region — Oxfordshire, Buckinghamshire and Hertfordshire — and counties in the Anglian region — Bedfordshire and Cambridgeshire — are some of the counties with the highest percentage of unacceptable water quality measurements,” the report said.

Gwent and Northumberland had the lowest levels of nutrient pollution with water quality of 100 percent.

The results of the report back up Office for Environmental Protection (OEP) findings that the country’s waterways are not in an acceptable state and that the government is not on course to satisfy the European Union’s Water Framework Directive (WFD), which has been incorporated into British law, reported The Guardian.

Since the 2016 Brexit vote, the United Kingdom’s Environment Agency (EA) has only been testing the water quality of rivers every three years instead of annually. The results of the survey have been given to the EA.

The WFD requires all rivers to have “good” ecological quality by 2027. However, Parliament lowered the requirement to 75 percent of waterways, which experts think is unlikely to be achieved without drastic measures.

The citizen science monitoring — conducted from June 7 to 10, 2024 — involved thousands of volunteers collecting more than 1,300 samples. They measured levels of phosphates and nitrates, nutrients commonly found in sewage — both untreated and treated — and in fertilizers from agricultural runoff.

Elevated nutrient levels can lead to uncontrolled plant and algal growth, high bacteria levels and lower water oxygen levels, all of which can kill plants and animals such as fish, mammals and insects.

“These results are truly disturbing – there are no parts of the UK unaffected by nutrient pollution… our rivers have been historically stressed by farming, and we’re seeing this being made worse by inappropriate or limited sewage treatment,” Woods said, as The Guardian reported. “There is a pressing need for both improvements to wastewater treatment processes and reductions in agricultural pollution to reduce threats to vulnerable freshwater systems. The government has committed to protect 30% of land for nature by 2030 – that will be meaningless if the rivers and streams running through the land, the arteries of life, are diseased.”

Jane Stewart, a citizen scientist born in Colchester who participated in the study, recalled growing up near the River Colne.

“I played on the banks of the young river, upstream in Halstead as I grew up in the 70s, using river clay to make pinch pots and catching minnows and sticklebacks in the shallow river with my friends. More recently I lived on the estuary of the river in both Brightlingsea and Wivenhoe, known for herrings and boat building. I have gone from seeing the river running clear and full as a young person, to now, in my old home town the river being clogged with plants and algae due to the run-off of nitrates. Old mills are sold on for luxury properties and the river has lost its purpose,” Stewart said in the report.

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Woods emphasized that the report was only possible because of the support of citizen scientists across the UK, reported The Guardian.

“This event has enabled people to better understand the health of their local rivers and catalysed grassroots action,” Woods said. “We want to see more citizen science testing and better use of this data by bodies such as the Environment Agency to help build a more positive future for our rivers.”