Plymouth Sound and Estuaries Special Area of Conservation (SAC) is located on the south coast of England and straddles the border between Devon and Cornwall. The SAC is a ria system with several marine inlets, including Plymouth Sound and its associated tributaries. The site is home to several nationally rare or scarce species, including red seaweed and stackhouse batters. It is also the only known spawning site for the allis shad.

Plymouth is a busy naval and commercial port, and management is needed to maintain the integrity of the site for nature. Like other estuaries, the pressures impacting upon it include commercial and naval shipping, commercial and recreational fishing and boating, as well as other water sports.

Plymouth. Photo credit Ocean Conservation Trust
Plymouth. Photo credit Ocean Conservation Trust

Plymouth Sound and Estuaries has been designated as a SAC for the estuarine and coastal features, including the wide-ranging mudflats and saltmarsh. These designated habitats are highly productive systems, forming a critical part of the food chain. They contain widespread and diverse infaunal communities rich in bivalves and other invertebrates and provide important feeding grounds for internationally important wildfowl. Notably, the only known natural population of the triangular club-rush in England is found on the Tamar.

Saltmarsh is an uncommon habitat in the south west of England and provides important roosting areas for birds. The site is home to communities of slender sea pens, fan mussels, and the nationally scarce tentacled lagoon worm. The saltmarsh fringes and seagrass act as nursery areas for commercially important juvenile bass.

The latest from this SAC


barge Solent 18 March 2022

England’s largest ever seagrass planting hits new milestone

£2.5m project led by Natural England has now planted seagrass across a total of 3.5 hectares of seabed. Seagrass can be as effective at storing carbon as our woodlands but UK has lost around half of its seagrass since the mid-1930s. Project partners to share expertise with marine conservation projects taking place around Europe to…


Seedling: Ocean Conservation Trust.

Spring seagrass planting is underway

Our wonderful volunteers are back in action packing seagrass seed bags for our springtime planting effort.

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