Lights Going Out On Lough Neagh

Lough Neagh is the UK's largest freshwater lake. It supplies more than 40% of Northern Ireland's drinking water. This Lough was also home to Europe's largest wild eel fishery and a biodiversity hot-spot. For example, enormous flocks of migrating waterbirds spent time there. In summer 2023, a vast bloom of blue-green algae covered this lake's surface, collapsing its ecosystems (https://www.theguardian.com/environment/2024/feb/19/like-the-flip-of-a-switch-its-gone-has-the-ecosystem-of-the-uk-largest-lake-collapsed-aoe). This collapse is a process called eutrophication. Such algal growth occurs when excessive nutients from fertilizer, wastewater and storm runoff, coincide with increasing sunlight and warmer temperatures. Sometimes the algae are toxic but, irrespective of this, any dense floating mat deprives water animals (insect larvae, fish etc.) of oxygen. Although Lough Neigh's algal mats disappeared over the winter, they are still lurking below the surface. As one observer noted of the lake's ecosystem " like the flip of a switch: It's gone". It won't be easy to return Lough Neigh to its former glories. We humans really have to look after our environment's more carefully.