New Forest Programme Manager Gemma Stride explains how her PhD research will uncover the impacts of pollution – and help us understand whether reducing combined sewage overflows will help biodiversity recover.

Freshwaters occupy less than one percent of the planet’s surface, yet they support nearly ten percent of all known species. These ecosystems are astonishingly rich and vital, but are also threatened. Globally, freshwater species populations have declined more rapidly than those of terrestrial or marine environments.

The pressures are complex and ubiquitous: land-use change, invasive species, water abstraction, and – of course – pollution. Here in the UK, most rivers and lakes fail to meet ‘Good’ ecological status under the Water Framework Directive. Despite decades of investment, water pollution remains one of the biggest challenges facing our rivers today.