A humble mushroom is offering bright new hope for cleaner rivers, and the idea is wonderfully simple.

Researchers have been testing turkey tail mushrooms as a natural, low-cost filter for water pollution. In Devon, England, the fungi were used to help remove sewage-related contamination, including E. coli bacteria, from river water.

The results were so encouraging that the water industry regulator OFWAT awarded local utility Anglian Water nearly $2 million to expand the approach.

The same nature-based solution has also shown promise in Lincolnshire, where turkey tail mushrooms were used to reduce agricultural runoff. That runoff often contains phosphorus and nitrogen, nutrients that can feed excessive algae growth and reduce oxygen in waterways.

The method is beautifully straightforward: bags of woodchips filled with turkey tail spores are placed at the bottom of a river. As the mushroom’s mycelium grows through the woodchips, it works like a living filter. In testing, it removed 80% of E. coli, 83% of phosphorus, and 35% of nitrogen.

The power of fungal networks has fascinated scientists for years. In another remarkable discovery, researchers have mapped underground fungal systems and found they stretch across astonishing distances.

Joshua Mercer of Anglian Water said the fungi could provide a “second line of defense” alongside standard sewage treatment.

“If [this work] can have a positive impact on water quality, then it’s benefiting everyone,” Joshua told the BBC.

He also shared a hopeful vision for the future: “When my daughter gets to my age, it would be great if people can just go and swim wherever they want.”

Mushrooms have already shown great potential as natural cleanup partners. Previous research has found that they can help absorb harmful heavy metals and even nuclear radiation, while other studies suggest they may help recover rare earth minerals from industrial waste.

From forests to rivers, these hardworking fungi are proving that some of nature’s quietest organisms may hold wonderfully practical answers for a cleaner, healthier world.