Carmarthen Bay and Estuaries/ Bae Caerfyrddin ac Aberoedd SAC

Status: Designated


Site overview

This is a large site made up of the estuaries of the Rivers Loughor, Ta and Tywi and the Gwendraeth. You can find mudflats and sandflats here as well as saltmarshes. Carmarthen Bay itself is an extensive, mainly sandy, shallow bay. The inlets and the three rivers systems provide a migratory route for salmon, lampreys and shad. This area is home to the near threatened European otter. 

MPA Type

Special Area of Conservation

Special Areas of Conservation (SACs) are strictly protected sites designated under European legislation. They contribute both to the UK MPA network and set up to protect habitat types and species considered to be most in need of conservation at a European level (excluding birds).

Designation date

1 January 1996

Surface Area

661.13 km2 (255.26 mi.2)


297.86 km (185.08 mi.)

  • Sea lamprey (Petromyzon marinus)

    A primitive jawless fish that looks a bit like an eel.

  • Allis shad (Alosa alosa)

    A rare and declining fish species which is part of the herring family. It grows in coastal waters and estuaries but migrates into rivers to breed. Almost all adults die after laying and fertilising the eggs.

  • Twaite shad (Alosa fallax)

    Sometimes called a ‘May fish’ as it returns to fresh water to breed in the spring, the twaite shad is a member of the herring family.

  • Otter (Lutra lutra)

    These fish-eating mammals completely disappeared from the waterways of most of central and southern England in just 50 years, their future now looks much brighter.

  • Atlantic salt meadows (Glauco-Puccinellietalia maritimae)

    Areas with specially adapted plants found in the upper reaches of saltmarshes that are not always reached by the tide. The habitat is used for grazing, but is also very important for birds.

  • Estuaries

    The downstream part of a river, where it nears the sea, which is influenced by the tide These complex habitats can include areas always submerged by the tide as well as those exposed at low tide. They can be exceptionally important feeding and breeding ar

  • Intertidal mudflats and sandflats (Mudflats and sandflats not covered by seawater at low tide)
  • Subtidal sandbanks

    Sandbanks which are slightly covered by sea water all the time

  • Shallow inlets and bays (Shallow inlets and bays)
  • Glasswort and other annuals colonising mud and sand (Salicornia and other annuals colonising mud and sand)

    Specialised plants able to thrive in the lower reaches of saltmarshes where the vegetation is frequently flooded by the tide. It is important as it can help the development of more stable saltmarsh.

Did you know?…

Over 170 parliamentarians from across the political spectrum signed up to our Marine Charter calling for a network of ‘marine protected areas’ in UK Seas

Over half a million people have voiced their support for ‘marine protected area’ designation in the UK through our campaigns

Over 500,000 records of undersea species and habitats have been collected by volunteer Seasearch divers