Littoral coarse sediment
Littoral coarse sediments include shores of mobile pebbles, cobbles and gravel, sometimes with varying amounts of coarse sand. The sediment is highly mobile and subject to high degrees of drying between tides. As a result, few species are able to survive in this environment. Beaches of mobile cobbles and pebbles tend to be devoid of macroinfauna, while gravelly shores may support limited numbers of crustaceans, such as Pectenogammarus planicrurus.
Situation: Littoral coarse sediments are found along relatively exposed open shores, where wave action prevents finer sediments from settling. Coarse sediments may also be present on the upper parts of shores where there are more stable, sandy biotopes on the lower and mid shore.
Temporal variation: The sediment particle size structure may vary seasonally, with relatively finer sediments able to settle during calmer conditions in summer. Where the sediment grain size is very large (at the interface between sediment and boulder shores), cobbles may be mobile during exposed winter conditions, but stable enough during summer months to support limited juvenile rocky shore epifauna (e.g. juvenile barnacles).
Source: EUNIS habitat classification
|EUNIS habitat type||code A2.1|
|Relation to||Annex I habitat types (EU Habitats Directive)|
Relation to other habitat types mentioned in legal instruments
Relation to vegetation types (syntaxa)Not available
Species mentioned in habitat description
|Classification||Code||Habitat type name||Relationship type|
|Palaearctic Habitat Classification 200112||11.28||Pebbly shore littoral communities||narrower|
|Palaearctic Habitat Classification 200112||17.1||Unvegetated shingle beaches||overlap|
|CORINE Land Cover||4.2.3.||Intertidal flats||n/a|
|Marine Habitat Classification Britain/Ireland 0405||LS.LCS||Littoral coarse sediment||same|
|Barcelona Convention 199812||II.3.||(MEDIOLITTORAL) STONES AND PEBBLES||same|
|Ramsar Wetland Types||E||Sand, shingle or pebble shores||wider|
|Phase 1 habitat classification (UK) 1993||H11||Intertidal: mud/sand||overlap|
|Phase 1 habitat classification (UK) 1993||H12||Intertidal: shingle/cobbles||overlap|