Flowing through the heart of London towards the North Sea, the Thames supports a huge amount of biodiversity, spilling out into wetlands. Founded in 43 CE, London has existed for nearly two millennia and grown into a thriving capital city which hosts more than 13% of the population in the United Kingdom. But this growth has led to environmental degradation, with pollution from sewage, roads, and industrial waste spilling into the Thames and flowing out to the estuary. Surveys in the 1950s measuring from Kew to Gravesend recorded no fish along the 69km stretch and by 1957, the river was declared “biologically dead”. In the decades that followed, policymakers took action, gradually improving water quality through stricter waste water quality legislation and through construction of sewage treatment works.
Despite significant improvements, there are many unresolved issues. The river and its estuary are still severely polluted by agricultural run off, sewage, microplastics, and chemicals of concern. Fragmentation and degradation of the natural habitats are prolific, with the estuary having lost 43% of its saltmarsh habitat over the past 130 years, more than 95% of its native oysters, and up to 87% of its seagrass meadows. With a planning grant from the Endangered Landscapes & Seascapes Programme, the Transforming the Thames project is creating a coastal habitat restoration plan for the Greater Thames Estuary at a seascape scale.
The current state of the Thames
Situated downstream from London, the Thames Estuary seascape covers an area of 250,000ha and borders three English counties: Kent, Essex and Suffolk. The Thames has long served residents of London and its surrounding area, providing food, water, coastal protection and livelihoods. It is also recognised for its importance for wildlife, being home to internationally important populations of birds including the UK’s second largest aggregation of wintering wildfowl. Recently, the East Atlantic Flyway – an important migration flightpath and pitstop used by around two million birds a year – has been put forward by the UK government as a candidate Natural World Heritage Site.
Sadly, the habitats in the Thames estuary are in a highly degraded state, declining in both size and quality. Alison Debney, Programme Lead for Estuaries and Wetlands Ecosystem Restoration says “the estuary has the potential to provide a multitude of ecosystem services through the habitats that naturally occur there, but as long as those habitats are fragmented and degraded, the true value of those ecosystem services are not being realised.”
The threat of climate change
The Thames Estuary is a stressed environment which is exacerbated by the impacts of climate change posing significant risks not only to wildlife but also to the 1.3 million people who live around the estuary. Poor water quality, habitat alteration, eutrophication, hypoxia, chemical contamination, the spread of invasive species, and coastal erosion are all linked to and worsened by a changing climate. Rising sea levels, another consequence of global warming, pose a significant threat to the estuary. Intertidal habitats such as seagrass meadows and saltmarshes are at risk of inundation, and coastal communities along the Thames face increased flooding risks. Between 1911 and 2018, the estuary experienced a 15cm rise in sea level, with the rate of rise accelerating from 1.4mm per year to 3.6mm per year between 1990 and 2018 in central London.
Transforming the Thames: A vision for the future
The Transforming the Thames project ultimately aims to restore the degraded and fragmented seascape of the Greater Thames Estuary, with the goal of revitalising it into a thriving coastal wetland that benefits both local communities and wildlife. In 2023, the project received a planning grant from the Endangered Landscapes & Seascapes Programme, enabling a collaborative effort among 12 organisations, including NGOs, government bodies, and land/seabed owners. Together, they are working to develop a comprehensive coastal habitat restoration plan to reverse habitat loss and fragmentation.
At present, the habitats in the Thames Estuary are fragmented, damaged, and too limited in extent to regenerate effectively or withstand further threats. However, within the Transforming the Thames project area, there is an estimated potential to restore 10,000 hectares of seagrass, 35,000 hectares of saltmarsh, and 7,000 hectares of native oyster habitat.
The path forward: A comprehensive restoration plan
The development of the Transforming the Thames coastal habitat restoration plan is built on four key pillars, each tackled by a dedicated working group of specialists:
- Active Restoration: This group is creating a prioritised plan of habitat restoration projects in key locations to maximise connectivity and ecological function.
- Barriers to Recovery: Focusing on how to overcome obstacles to existing habitat quality and extent, this group aims to remove the impediments to restoration.
- Policy Integration: Ensuring that the Coastal Habitat Restoration Plan is fully aligned with nature conservation and regeneration policies across the estuary and nationally.
- Sustainable Finance: Developing a financing plan using sustainable finance mechanisms to ensure the long-term viability of the project.
These efforts will culminate in a holistic, costed, and co-created restoration plan. While the initial plan will cover the first five years of delivery, the ambition of the Transforming the Thames project is to continue its work for many years, until the Thames Estuary is restored, reconnected, and resilient.
This article was written by Olwen Belgrove, project officer for Transforming the Thames. To find out more about the planning grant, visit the Transforming the Thames project page.
