Biodiversity & Conservation

Muddy sand shores



Image Joint Nature Conservation Committee - View across a cockle strand (biotope LMS.Pcer). Image width foreground ca 10 m.
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Distribution map

LS.LMS.MS recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

  • EC_Habitats
  • UK_BAP

Marine natural heritage importance

Listed under EC Habitats Directive
UK Biodiversity Action Plan
National importance Common
Habitat Directive feature (Annex 1) Mudflats and sandflats not covered by seawater at low tide
Large shallow inlets and bays

Biotope importance

Intertidal areas are well-defined juvenile fish nursery areas (Costa & Elliot, 1991). Mud and sandflats are important nursery areas for plaice, smaller fish settling on mudflats and larger fish found on sandflats. Mud and sandflats are feeding areas for sea bass and flounder. Intertidal areas are important migration routes for salmon and shad.

Intertidal mud flats are important wintering and migratory feeding grounds for wildfowl. Dependant species include brent geese, shelduck (a red data book species), pintail, oystercatcher, ringed plover, grey plover, bar-tailed and black tailed godwits, curlew, redshank, knot, dunlin and sanderling. Grey geese and whooper swan may use this habitat for roosting (Jones & Key, 1989; Davidson et al., 1991). Muddy sands tend to support a more extensive bird population than mudflats (Jones et al., 2000).


Intertidal mudflats and sandflats often abut recreational beaches. Mudflats and muddy sand may be used for bait collection or may form well used shell fish beds, e.g. cockles (Cerastoderma edule).

Additional information icon Additional information

Littoral muddy sands occur in estuaries, adjacent sedimentary coasts, sheltered embayments and semi-enclosed areas. Intertidal mudflats and sandflats, of which there are many examples, dominate marine and estuarine habitats and may cover large areas from a few hectares to several sq. kilometres. Occurs in three Annex I Habitat Directive 'habitats' and is represented in over 50% of the candidate SACs in the UK. (Elliot et al., 1998). They are of economic importance for: support nurseries for flatfish and round fish;support shellfish beds, e.g. cockle and razor fish;feeding grounds for shrimp;important areas for migratory and resident populations of wildfowl;absorb or dissipate wave energy and provide flood and coastal defence (Elliot et al., 1998).

This review can be cited as follows:

Tyler-Walters, H. & Marshall, C. 2006. Muddy sand shores. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 27/11/2015]. Available from: <>