Biodiversity & Conservation

Mytilus edulis beds with hydroids and ascidians on tide-swept moderately exposed circalittoral rock

CR.MCR.CMus.CMyt


MCR.MytHAs

Image Anon. - Mytilus edulis beds with hydroids and ascidians on tide-swept moderately exposed circalittoral rock. Image width ca 1m in foreground.
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Distribution map

CR.MCR.CMus.CMyt recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)


  • EC_Habitats

For a list of 2004 characterising species please see the JNCC website.

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 other Balanus crenatus An acorn barnacle
Important other Alcyonium digitatum Dead man's fingers
Important other Urticina felina Dahlia anemone

Explanation

The MCR.MytHAs biotope is characterized by the presence of Mytilus edulis. The other members of the community, and characterizing species can probably colonize the substratum in the absence of Mytilus edulis and have not been used as species indicative of biotope sensitivity. Therefore, Mytilus edulis has been included as a key structural species, since it provides secondary productivity, and substratum within the biotope. Asterias rubens is an important predator in mussel biotopes, together with other starfish, crabs and fish and is known to limit the distribution of mussel communities. Although the selected 'indicative species' are particularly important in undertaking the assessment because they have been subject to detailed research, account is taken of knowledge of the biology of all characterizing species in the biotope when undertaking an assessment of sensitivity of this biotope.

Additional information

A total of 278 species were reported within records of this biotope in the MNCR surveys (JNCC, 1999).


This review can be cited as follows:

Tyler-Walters, H. 2001. Mytilus edulis beds with hydroids and ascidians on tide-swept moderately exposed circalittoral rock. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 23/10/2014]. Available from: <http://www.marlin.ac.uk/habitatreproduction.php?habitatid=208&code=2004>