The Thames River: How It Recovered from "Biological Death"

The Thames River, once infamous for its pollution and foul odor, is now a symbol of environmental recovery. In 1858, the river became notorious during the "Great Stink," when London's sewage overflowed into its waters, causing widespread disease and unbearable smells. The pollution was so severe that sections of the Thames were declared biologically dead, unable to support life.

Yet, over a century later, the river has made a stunning comeback. According to a report published on Wednesday by Andrew Terry, Director of Conservation and Policy at the Zoological Society of London (ZSL), the Thames is now home to a rich variety of wildlife. Terry highlighted significant improvements in key species and habitats, along with a decrease in pollution pressures. He wrote, “Today, the river hosts an abundance of wildlife as diverse as the city of London itself.”

One of the most notable recoveries is the return of the avocet, a migratory bird that had been extinct in England since 1842 due to habitat loss. After World War II, the avocet began to reappear along the Thames estuary, and its population has more than doubled over the past 30 years.

Despite these promising trends, the report also warned of ongoing challenges. Climate change is having a noticeable impact on the Thames, which serves as an essential water source for London. The river's water quality has improved, thanks in part to the expansion of sewage treatment plants and restrictions on industrial waste discharge since the 1960s. However, concerns remain. For instance, a study published last year found high levels of microplastics in water samples taken from the Thames in 2017.

These microplastics pose significant risks to marine life, as they can block the digestive systems of animals and lead to starvation. National Geographic has reported that animals ingesting plastics may suffer fatal consequences when their stomachs become filled with non-digestible material.

While the outlook for birds and marine mammals along the Thames is improving in both the short and long term, the report noted that fish populations face more complex challenges, with some species experiencing declines. Nevertheless, the Thames' remarkable recovery stands as a testament to the positive impact of environmental conservation efforts, even as new threats continue to emerge.