Eutrophication-Across the Nation

Eutrophication occurs when waterbodies are contaminated by phosphates and nitrogen. These chemicals are generally from runoff from farming activities. These pollutants are either derived from fertilisers, excessively applied to crops, or in the faeces/urine of factory-farmed animals. These contaminants cause blooms of toxic cyanobacteria. The blooms remove oxygen from the water, decimating populations of fish and other aquatic organisms. Lough Neagh is the UK's largest lake, draining around 50% of Northern Ireland's land. This lake has seen big increases in toxic algal blooms and a consequent collapse of fishery incomes (https://www.theguardian.com/environment/2025/aug/30/uk-largest-lake-lough-neagh-faces-environmental-crisis-as-rescue-plans-stall). Eutrophication of lakes and rivers is a serious problem in many parts of the world. The usual solution is to reduce farming-related runoff of phosphates and nitrogen. It requires investment in water treatment and cooperation from farming interests.