Biodiversity & Conservation

Mytilus edulis beds on variable salinity infralittoral mixed sediment


<i>%Mytilus edulis%</i> beds on variable salinity infralittoral mixed sediment
Distribution map

SS.IMX.EstMx.MytV recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

  • EC_Habitats
  • UK_BAP

Species indicative of sensitivity

To assess the sensitivity of the biotope, the sensitivity of component species is reviewed. Those species that are considered to be particularly indicative of the sensitivity of the biotope, and for which research has been undertaken in detail are shown below (see selection criteria). The biology of other component species of the biotope is also taken into account wherever information is known to the researcher.

Community Importance Species name Common Name
Key structural Mytilus edulis Common mussel
Important functional Asterias rubens Common starfish
Important functional Nucella lapillus Dog whelk


Mytilus edulis populations stabilize the sediment surface and build up a bed of organically enriched 'mussel mud' to form a biogenic reef in this biotope (Holt et al., 1998). Therefore, the mussel bed modifies the substratum and adds habitat complexity in the form of hard substratum (its shells), the mussel matrix and the mussel mud. Mytilus edulis is therefore, regarded as the key structural species in this biotope. Predators such as Asterias rubens and Nucella lapillus influence the population structure and dynamics of the bed are therefore included as important functional species. Most other associated species live within the biotope without greatly influencing its structure or function.

Additional information

The MNCR recorded 133 species within this biotope (JNCC, 1999). Reduced salinity, estuarine environments are generally of low species richness due to the physiological rigors of the environment. While this biotope is probably of low species richness when compared to other full salinity or intertidal mussel biotopes, the biotope still represents a species rich habitat within reduced salinity habitats.

This review can be cited as follows:

2001. Mytilus edulis beds on variable salinity infralittoral mixed sediment. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 29/11/2015]. Available from: <>