A citizen science program has the decline of one of the country’s most important chalk streams following claims by Environment Agency officials that it had not deteriorated. The SmartRivers program run by the charity WildFish, which researches freshwater invertebrates, reported “strong declines in relation to chemical pressure” on the River Avon in Wiltshire. It said its data indicated a decline in the condition of the river over the past five years.
The charity compiled a report on its findings after the conservation groups said at a meeting by the Environment Agency in August that “the Avon has not deteriorated in water quality in the last five years”. Wiltshire Fishery Association head of water quality David Holroyd said the numbers of invertebrates collected in spring and autumn samples from 2019 and 2023 at 11 sites in the upper Avon showed a decline.
He said the invertebrates are “the canary in the coal mine” and data suggests they are “being poisoned by chemicals in the river”.
WildFish says the findings highlight the crucial role citizen scientists have played in monitoring river health following a decline in the number of tests conducted by regulators over the past decade. The SmartRivers program in England, Wales and Scotland now covers 95 rivers, according to a new report by the WildFish charity.
Freshwater invertebrates support the aquatic food ecosystem, ranging from river flies and beetles to molluscs, worms and crustaceans. In the most recent results for all monitored rivers in 2022, volunteers found 268 different invertebrate species and counted 343,077 specimens. Invertebrate species have different tolerances to pollution. An analysis of the species present, together with their numbers, helps to identify pressures on water quality from farming, sewage discharge and runoff from roads and residential areas.
Janina Gray, head of science and environmental policy at WildFish, said the ecological condition of a river was assessed under the Water Framework Directive, a European Union directive that was transposed into law for England and Wales after Brexit. She said the current assessments “did not set the bar high enough”.
The Environment Agency insisted the Avon had not deteriorated under the water framework guidelines classification at the meeting in August, Gray said, adding: “It is frustrating that the river is declining year on year and the legislation is not protecting it. It is one of the most protected rivers we have in this country. It is very diverse in terms of its fish population. If we can’t protect the Avon, there probably isn’t much hope for many other rivers. We need a comprehensive monitoring network to be able to determine where the problems are occurring and that is why the SmartRivers is so important.”
Gray said WildFish was working closely with the Environment Agency and other partners to identify pressures on the river. An Environment Agency spokesman said: “On the River Avon we are working with partners in the area to explore how we can best use citizen science evidence alongside our own monitoring data to further increase understanding of water quality.”
A recent analysis by WildFish reported that every river sampled in the Windermere catchment for the SmartRivers program was affected by United Utilities waste water treatment works. It found that pollution-sensitive river fly species showed declines of up to 76% compared to appropriate upstream habitat.
United Utilities said the plants were operating in accordance with environmental permits.
