Bold claim: pollution is choking our rivers and, with it, the joy of fishing—and this isn’t just theory, it’s being documented across the UK. But here’s where it gets controversial: the scale and pace of the problem may be bigger—and messier—than many people realize.
A citizen science effort by the Angling Trust, a non-profit group, collected almost 4,000 samples from 80 river catchments to fill gaps left by irregular regulator testing. The study, conducted between July 2024 and July 2025, found that nearly half of the samples exceeded a key nitrate pollution threshold that ecologists consider harmful. Specifically, 49.9% of samples were above this level, compared with 45.9% in 2023/24 and 43.8% in 2022/23.
What nitrate pollution means in practice: nitrates mainly come from sewage works and agricultural fertilisers. When concentrations rise too high, algae bloom and deplete oxygen in the water, which can suffocate fish and other aquatic life. This is why many anglers and scientists view nitrates as a nutrient pollutant with serious ecological consequences.
The Warwickshire Avon stood out as a hotspot. In this heavily sampled catchment, about 75% of the tests exceeded the ecological limit, prompting the Angling Trust to describe the nitrate problem there as endemic. A map from a water industry source revealed a day last year when Severn Trent spilled raw sewage into the river more than 130 times, highlighting a troubling pattern of pollution events.
From the observers on the banks: Andy Hammerton, head bailiff for the Girling Angling Society (which holds fishing rights on the Avon), has watched local fishing deteriorate over decades. He noted a pronounced slowdown in recent years, with many stretches yielding fewer bites than in the past. He describes pollution as a constant worry and a major factor in the sport’s decline.
The legal nitrate limit is 11.3 parts per million, but the Angling Trust uses a stricter ecological threshold of 5 ppm, arguing that algal blooms can be triggered at that level.
A spring and summer spike in nitrate levels followed a hot, dry period that reduced river flows, concentrating pollutants and worsening conditions across rivers nationwide.
Angling Trust freshwater campaigns officer Alex Farquhar explained the broader impact: when nutrients surge, algal blooms form, fish suffer from low oxygen, and anglers often wonder where the fish have gone.
Beyond nitrates, the survey also raised concerns about phosphates in some streams. In the Test and Itchen catchments in Hampshire, phosphate levels were considered harmful in 36% and 54% of samples, respectively. These chalk streams are cherished fishing spots, including Bidford-on-Avon, known for brown trout and grayling.
Jim Murray, a campaigning angler and actor, framed the findings starkly: in chalk streams, water quality is failing, with catastrophic consequences for native species like salmon.
The Times’ Clean it Up initiative calls for stronger regulation and smarter investment to repair river health. In response, Defra emphasizes a commitment to cleaning up waterways by reducing sewage and agricultural pollution, noting actions such as banning certain bonuses for water company executives, securing record investment in infrastructure, and tightening rules on agricultural pollution.
Water industry stakeholders acknowledge the problem too. Water UK says sewage spills are unacceptable and pledges to cut spills by upgrading treatment works and expanding capacity as part of a multi-year, multibillion-pound program aimed at safeguarding rivers, seas, and water supplies.
This complex picture shows progress alongside persistent challenges. It also invites important questions: Are we moving fast enough to protect our rivers and the fishing they support? What mix of regulation, investment, and accountability will best reduce nutrient pollution—without stifling agriculture or urban development? Share your views in the comments: do you think industry accountability is adequate, or should policies be tightened even further to prioritize river health over other interests? And what practical steps would you suggest for communities to help restore their local waterways?
