Blue mussel (Mytilus edulis) beds

Blue Mussel Beds © Paul Kay


These small, blue mussels are a common sight on UK coasts.  They can form extensive beds, with living and dead mussels, sand and mud all bound together by the mussels’ sticky ‘beards’ of byssus threads.  Blue mussel beds occur mostly on the lower shore between the tides or permanently submerged in shallow water.

Mussel beds provide an important food source for wintering waders. When beds were lost from parts of Holland in 1990, the eider duck numbers decline significantly.  Otters may also get some of their food supply from blue mussel beds, and the ‘mussel mud’ formed by the blue mussels’ waste is an important source of nutrients for animals living within the seabed.

Blue mussel beds have a particularly important role where they occur on soft seabeds, as they provide a hard surface in otherwise muddy or sandy areas. This attracts and supports a greater range of marine life than would otherwise be found there including seaweeds, anemones, barnacles, sea snails, crabs, starfish and worms.

The threats to blue mussel beds include their removal for food or bait, and the damage caused by mobile fishing gear, anchoring or mooring chains, or, for beds found between the tides, by trampling.  They are also at risk from shoreline building developments, dredging, and pollution.

Blue mussel beds take at least five years to recover from damage, and those in southern England are some of the most threatened in Europe.

For the official habitat definition please see the documents listed below.


European distribution

Blue mussels are widespread on the shore and in shallow water around the coasts of the UK and Europe.  Significant beds of blue mussels on soft sea beds are found in scattered locations within this broad range.


Conservation status/need

Blue mussel beds fact

  • This is a UK BAP Priority Habitat (BAP habitats are now Habitats of Principal Importance/Priority Habitats).
  • OSPAR List of Threatened and/or Declining Species and Habitats (Region II – Greater North Sea, and Region III – Celtic Sea)
  • Blue mussel beds can also be key features of habitats listed in Annex I of the Habitats Directive


Official definition

UK Biodiversity Action Plan; Priority Habitat Descriptions. BRIG (ed. Ant Maddock) 2008 (updated December 2011)

Descriptions of habitats on the OSPAR list of threatened and/or declining species and habitats (OSPAR agreement 2008/07).


Further information

Case Reports for the OSPAR List of threatened and/or declining species and habitats

Marine Life Information Network - Mytilus edulis beds

Food and Agriculture Organization of the United Nations - Mytilus edulis

Marine Species Identification Portal - Mytilus edulis

World Register of Marine Species - Mytilus edulis

Marine Life Information Network - Mytilus edulis beds

JNCC - UK BAP Priority Species and Habitats

JNCC EUNIS habitat correlations table