Transforming the Thames
Restoring saltmarsh, seagrass, oyster reefs, and coastal wetlands in the Greater Thames Estuary to recover biodiversity, strengthen resilience, and connect people with nature.
The Greater Thames Estuary is a sprawling seascape of 250,000 hectares, where the river Thames meets the North Sea. Its habitats include saltmarsh, seagrass beds, oyster reefs, mudflats, saline lagoons, and coastal grazing marshes. These ecosystems support hundreds of species, from avocet and ringed plover to the critically endangered European eel and spiny seahorse. They also provide vital services for people, including carbon storage, nutrient regulation, flood protection, and recreation.
Despite their importance, these habitats are fragmented and degraded. More than 40% of saltmarsh has been lost, along with 95% of native oysters and up to 87% of seagrass. Climate change is adding new pressures, with rising sea levels, warming waters, and increased nutrient pollution. Transforming the Thames brings together a wide partnership to restore, reconnect, and revitalise this seascape for nature and communities.
Zoological Society of London (ZSL)
The Greater Thames Estuary
England
Ongoing since 2025
250,000 ha
Oyster reefs, intertidal seagrass, saltmarsh, sand and shingle bird nesting habitat, saline lagoon, and coastal grazing marsh
European flat oyster, Intertidal seagrass, Brent geese, ringed plover, avocet, sea aster mining bee, European eel, spiny seahorse
Why this place matters
The Thames Estuary’s coastal wetlands lie on one of eight global flyways for migratory birds and have been nominated by the UK government as a Natural World Heritage Site.
The Thames Estuary is one of the UK’s most important coastal wetlands, recognised through 86 conservation designations and proposed as a Natural World Heritage Site. Lying on one of eight global flyways, it supports vast numbers of migratory birds and diverse marine life. For people, it provides food, jobs, flood protection, and cultural value.
Yet centuries of land-use change and development have altered its natural systems. Major ports, offshore wind farms, and growing coastal populations now sit alongside degraded habitats. Still, the estuary holds huge potential: national mapping shows it could provide up to 53,000 hectares for future saltmarsh, seagrass, and oyster recovery, offering both ecological and economic renewal.
Action on the ground
Transforming the Thames is uniting organisations to deliver seascape-scale restoration.
Inspire communities by offering volunteer opportunities and creating stronger connections to nature.
Reduce threats by tackling water pollution pathways and improving conditions for existing habitats.
Build capacity through evidence gathering, skills development, and practitioner training.
Prepare for scaling up through a rolling programme of ready-to-go projects.
Restore 320 hectares of coastal habitats across 14 sites, including seagrass beds, saltmarsh, oyster reefs, saline lagoons, and nesting habitats for coastal birds.
Visit the Transforming the Thames website
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