|Basic Information||Biotope classification||Ecology||Habitat preferences and distribution||Species composition||Sensitivity||Importance|
Image Christine Howson - Lithothamnion glaciale nodules amongst pebbles with the sunstar Crossaster papposus, Isle of Lewis. Image width ca 20 cm.
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SS.IGS.Mrl.Lgla recorded () and expected () distribution in Britain and Ireland (see below)
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||Lithothamnion glaciale||Maerl|
|Important functional||Ophiothrix fragilis||Common brittlestar|
|Important functional||Psammechinus miliaris||Green sea urchin|
The biotope is named after the key structural species Lithothamnion glaciale. Two other species have been selected as being representative of this biotope (Ophiothrix fragilis, and Psammechinus miliaris ). Ophiothrix fragilis has a potentially important functional role in the biotope as a suspension feeder. Benthic suspension feeders such as Ophiothrix fragilis can occur in very high densities and can have a dominant role in the main nutrient exchanges in estuarine and coastal ecosystems (Dame, 1993 cited in Smaal, 1994; Lefebvre & Davoult, 1997). Suspension feeders are important in coastal ecosystems because they can remove large amounts of suspended particulate matter (Davoult & Gounin, 1995). Psammechinus miliaris is an active grazing omnivore that may have a functional role in modifying densities of other species. N.B. These three species are often but not necessarily always present in this biotope. Other similar species may be present in addition to or in place of these two species. Even if the three selected species are not present, or other similar species are more faithful or abundant, the sensitivity assessments can give a broad impression of the sensitivity of the biotope. In undertaking an assessment of sensitivity of this biotope, account is taken of knowledge of the biology of all characterizing species in the biotope. However, the selected 'indicative species' are particularly important in undertaking the assessment because they have been subject to detailed research.
This review can be cited as follows:
Jackson, A. 2006. Lithothamnion glaciale maerl beds in tide-swept variable salinity infralittoral gravel. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 28/03/2015]. Available from: <http://www.marlin.ac.uk/habitatreproduction.php?habitatid=7&code=1997>