The Essex Estuaries Special Area of Conservation (SAC) is the second largest estuarine site on the east coast of England and covers 472 km2 of mostly undeveloped coastal plain estuarine systems including the Colne, Blackwater, Crouch and Roach estuaries together with extensive mudflats at Dengie, Foulness and Maplin. Starting at Shoeburyness in the south, the SAC extends northwards to Jaywick in North East Essex.

Making up a significant portion of the UK’s saltmarsh resource, the SAC contains almost 20 per cent of British Saltmarshes and includes a diverse range of substrate habitats and sediments from fine estuarine muds and muddy sand to coarse sand and gravel. With high nutrient contents, it is a highly productive coastal ecosystem supporting mudflats, sandflats and sub tidal areas which many migratory birds rely on throughout their lifecycles. Large wildfowl populations are sustained by saltmarsh flowers, terrestrial grasses, seeds and seagrasses such as the abundant seagrass beds at Shoebury and Foulness.

Essex Estuaries SAC/David Overton
Essex Estuaries SAC/David Overton

Saltmarshes also have an important role in capturing and storing carbon within the accumulated sediment layers which enhance flood defences by absorbing wave energy in a natural buffer zone between land and sea.

The Essex Estuaries SAC is part of the ReMEDIES project as it contains seven Sites of Special Scientific Interest (SSSIs), and 15 other protected areas, including five special protected areas focusing on the protection of internationally important bird species. The area’s national and international significance partly relies on the favourable status of the seagrass beds. Moving the seagrass beds towards a more favourable condition through community engagement, the ReMEDIES project in Essex will continue to sustain a wide range of species, process structures and functions, not just for England but for the international community too.

The latest from this SAC


Zostera noltii/Jo Sinclair

Protecting the Essex Estuaries

We partnered Essex Wildlife Trust and trained a team of volunteers to conduct recreational activity observations along the Essex coastline over the summer. Alan Kavanagh, Natural England’s Essex Site Lead, and volunteer Cameron Alston, explain how and why we did it… Why Essex Estuaries? With 350 miles of varied coastline, Essex provides unique opportunities to…

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