09/07/2025 - Climate change fuelling dangerous river pollution across England and Wales, warns Angling Trust
The Angling Trust is warning that climate change is intensifying pollution in Britain’s rivers, after volunteer monitoring revealed record levels of water pollution during the exceptionally warm spring of 2025.
New data from the Trust’s Anglers Against Pollution Water Quality Monitoring Network (WQMN) shows how the UK’s hottest and sunniest spring on record has amplified nitrate and ammonia pollution, increasing risks to fish, wildlife, and river health.
UK rivers are already under severe stress, with just 14% achieving good ecological status, and the latest findings suggest changing weather patterns driven by global warming is making a bad situation worse.
Rising River Temperatures – A Hidden Threat to Fish and Wildlife
WQMN data shows the UK’s record air temperatures in spring 2025 directly translated into significantly warmer rivers and lakes. March, April, and May 2025 were the warmest for river temperatures in three years of monitoring. Compared to the relatively average spring of 2023, river temperatures in March were 1.7°C higher, April was 1.8°C higher, and May saw a 0.6°C increase.
These increases appear modest but have serious ecological consequences, especially for cold-water species such as wild brown trout and the critically endangered Atlantic salmon. Warmer water holds less dissolved oxygen, making fish more vulnerable to stress and disease. It also accelerates the toxicity of pollutants like ammonia, disrupts breeding cycles, fuels algal blooms, and favours invasive species.
Fish Kills on the Rise
The ecological consequences of this year’s warm, dry conditions are already being seen in rivers across England and Wales. So far in 2025, the Angling Trust has recorded 87 confirmed fish kill incidents, including those caused by pollution, low oxygen, and natural factors. Incidents of low flows which reduce river levels and concentrate pollution, are higher than seen at this point in 2023 and 2024, with 36 confirmed incidents already this year. Though the rate of increase slowed slightly in June, experts expect final figures for the month to exceed both 2023 and 2024 levels. Fish rescues have already been needed on the River Teme at Stanage and River Redlake at Bucknall
Key Findings: Climate Heat Boosts River Pollution
Record Spring Temperatures: Spring 2025 was the hottest ever recorded in the UK, with all four nations logging their warmest spring since records began in 1884. Combined with extremely low rainfall, these conditions allowed pollutants to concentrate in rivers.
Surge in Nitrate Pollution: Nitrate levels spiked alongside rising temperatures and low river flows. Over 53% of spring 2025 samples contained nitrate above 5ppm – a concentration known to fuel algal blooms – compared to only a minority of samples in previous years. Alarmingly, every month of spring 2025 saw average nitrate levels exceed this threshold. Additionally, 6.4% of tests breached the upper limit of 11.3ppm, roughly triple the breach rate seen in 2023.
Rising Ammonia Levels: Toxic ammonia pollution also hit its highest levels in 2025. Around 5.4% of ammonia tests failed to meet good ecological standards, up from 2.2% in spring 2023. Warmer water significantly increases ammonia’s toxicity, compounding the risk to fish and aquatic life.
Electrical Conductivity Spikes: Mean electrical conductivity, a general indicator of dissolved pollutants, was 17% higher than in 2024 and 33% higher than in 2023, signalling concentrated pollution during warm, dry conditions.
Extreme Weather Fuelling an Ecological Crisis
These pollution spikes are closely linked to extreme weather driven by climate change. Spring 2025 not only broke temperature records – it was extraordinarily dry. By mid-May, the UK was experiencing its driest spring in over 100 years, and despite some rain in June, the season ranked as the sixth-driest spring since 1836.
This combination of record warmth and drought allowed routine pollution sources – treated sewage, farm runoff, and urban discharge – to concentrate in rivers, as low rainfall meant less dilution. The Angling Trust warns that such climate-driven extremes are amplifying the impacts of pollution, creating a perfect storm of environmental stress.
Anglers Call for Urgent Action
Faced with clear evidence that climate change is worsening the impacts of pollution, the Angling Trust is calling for stronger action from government and regulators to reduce nutrient and sewage pollution in rivers.
“These results are a wake-up call to tackle the double impact of river pollution and climate change,” said Stuart Singleton-White, Head of Campaigns at the Angling Trust. “We urgently need to see much tougher regulation resulting in immediate reductions in river pollution, goals for 2030 are too little too late.”
Join the Fight for Clean Rivers
The Angling Trust also highlights the power of citizen science in tackling this crisis. The WQMN, part of the Anglers Against Pollution campaign, is the largest regular citizen science water quality programme in England and Wales. Some 800 trained volunteers from more than 300 angling clubs have now submitted over 10,000 pollution monitoring samples.
“We need more people to get involved,” urged Jamie Cook, CEO of the Angling Trust.“ Anglers can play a vital role to protect rivers by joining the Water Quality Monitoring Network. Together, we can build the evidence to fight pollution, protect fish and wildlife, and safeguard the future of our rivers. Where necessary the Angling Trust’s sister organisation, Fish Legal, will also use this evidence to support action against polluters and demand restoration of damaged rivers.”
Get Involved
The Angling Trust is calling for more volunteers to be the eyes and ears on the water. WQMN volunteers receive simple test kits and training to monitor river health, building a clearer national picture of the challenges facing our rivers.
FOLLOW THE LINK below to find out more, support the Angling Trust, or join the Water Quality Monitoring
https://mail.anglingtrust.net/c/AQjyyBUQoZGGARiGtdQDINv7uwlMnxne04jWdysndmdlMXhX7ZIIv7FKnVLPpqyzSAI0kA
Back to the News List
