Biodiversity & Conservation

Ascophyllum nodosum ecad mackaii beds on extremely sheltered mid eulittoral mixed substrata



Image Sue Scott - A dense mat of Ascophyllum nodosum mackaii. Image width ca 40 cm.
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Distribution map

LR.LLR.FVS.Ascmac recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

  • EC_Habitats
  • UK_BAP

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.

Species found especially in this biotope

  • Ascophyllum nodosum ecad mackaii
Community Importance Species name Common Name
Key structural Ascophyllum nodosum Egg wrack
Important characterizing Hyale prevostii An amphipod
Important characterizing Littorina littorea Common periwinkle


The biotope often consists of both the free-living Ascophyllum nodosum ecad mackaii and on cobbles and other hard substrata the normal form of Ascophyllum nodosum. The beds often provide a habitat for other species such as gammarid amphipods like Hyale prevostii and the periwinkle Littorina littorea.

Additional information

This review can be cited as follows:

Hill, J.M. 2001. Ascophyllum nodosum ecad mackaii beds on extremely sheltered mid eulittoral mixed substrata. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 26/11/2015]. Available from: <>