Description of [Phymatolithon calcareum] maerl beds with red seaweeds in shallow infralittoral clean gravel or coarse sand
Lower infralittoral maerl beds characterised by Phymatolithon calcareum in gravels and sand with a variety of associated echinoderms. The echinoderm Neopentadactyla mixta is frequently observed in this biotope. Other echinoderms such as Echinus esculentus, Ophiura albida and rarely Luidia ciliaris may also be present. Red seaweed such as Plocamium cartilagineum may be present but at a much lower abundance than in A5.5111 and with fewer species present. Other, more ubiquitous echinoderms such as Asterias rubens may also be found in low numbers throughout A5.511 subunits.