Sewage discharge into rivers in the UK has a significant impact on nutrient levels, leading to high nutrient concentrations and detrimental effects.

In the UK, nutrient levels in rivers are primarily influenced by human activities, particularly agriculture and treated and untreated sewage. Key nutrients include nitrogen and phosphorus, which are essential for plant growth but can lead to eutrophication when excessive amounts enter water bodies, causing harmful algal blooms and impacting aquatic life.

 

Floating pennywort is so damaging to native flora and fauna that it is listed under Schedule 9 to the Wildlife and Countryside Act 1981, meaning it is illegal to cause it to grow in the wild. Since 2014, it has also been banned from sale in the UK.  Its dominating presence steals sunlight, smothers habitats and crowds out native plants. It can cause an increase in water temperatures, and create mosquito breeding areas.  When pennywort dies back in the winter, excessive nutrients can build up in the water and damage ecosystems.  Floating pennywort’s excessive coverage across the surface of water can impede flow, causing oxygen depletion for fish and other wildlife, which in turn impacts food webs.