A citizen science survey of Windermere, England's largest lake, revealed concerning pollution levels, especially during summer, with harmful bacteria and excess phosphorus affecting water quality.

Conducted over two and a half years by 350 volunteers at more than 100 sites, the survey found that much of the shoreline failed water quality standards for bacteria, impacting activities like swimming and water sports.

While the overall water quality is rated 'good,' certain hotspots, particularly in summer, show 'poor' conditions due to bacterial contamination and elevated phosphorus levels, threatening aquatic ecosystems.

The UK government has pledged to 'clean up Windermere,' addressing pollution from sewage and land use, with increased regulation and monitoring efforts underway, following criticism over illegal sewage dumping.

Environment Secretary Steve Reed has promised to improve water quality, including tackling illegal discharges and land-based pollution, aiming to protect the lake's ecological and social value.

The survey identified Bowness Bay as a pollution hotspot, with E. coli and intestinal enterococci levels five to seven times higher than the lake's average, highlighting localized contamination issues.

Excess phosphorus levels, mainly from wastewater and agricultural runoff, pose risks of algal blooms and ecosystem damage, with tests confirming phosphorus exceeding expected standards.

Campaigners and scientists, including the Freshwater Biological Association, are calling for urgent investigation of pollution hotspots, increased year-round monitoring, and investment in wastewater treatment infrastructure.

Experts warn that if immediate action isn't taken, threatened species like Arctic char could decline, and Windermere's ecological and cultural significance may be compromised.

Simon Johnson of the Freshwater Biological Association emphasized the need for decisive measures to improve water quality and protect rare and threatened species in the lake.

Campaign voices, including Save Windermere, stress the importance of enhanced monitoring, hotspot investigation, and proper management of wastewater facilities to safeguard the lake's health.

The findings underscore broader environmental challenges in the Lake District, which attracts millions of visitors annually and contributes significantly to the local economy, but faces ongoing pollution issues.