LS.LSa.MoSa.AmSco.Pon - Pontocrates arenarius in littoral mobile sand

LS.LSa.MoSa.AmSco.Pon
Pontocrates arenarius in littoral mobile sand

Full Hierarchy >> LS >> LS.LSa >> LS.LSa.MoSa >> LS.LSa.MoSa.AmSco >> LS.LSa.MoSa.AmSco.Pon

Habitat (physical) description

Distribution

Salinity:	Full (30-35 ppt)
Wave exposure:	Extremely exposed, Very exposed, Exposed, Moderately exposed
Tidal streams:
Substratum:	Medium sand; fine sand
Zone:
Depth Band:	Lower shore, Mid shore, Upper shore
Other Features:
Download comparative physical and biological data. The comparative tables enable a rapid comparison of the species composition and principal physical characteristics between a given set of biotopes.

Previous code

This biotope occurred in previous versions of the classification as:
LGS.AP.Pon (part) - Version: 97.06
LGS.S.AEur (part) - Version: 97.06
LGS.S.AP.P (part) - Version: 97.06
LSND.AE (part) - Version: 6.95
LSND.AP (part) - Version: 6.95

Distribution of habitat LS.LSa.MoSa.AmSco.Pon Pontocrates arenarius in littoral mobile sand, based on records on the JNCC marine database. Red dots represent records on which the biotope is based. Blue dots show orther certain records, black dots show records tentatively assigned to this biotope.

Biotope description

Mainly on the mid and lower shore on wave-exposed or moderately wave-exposed coasts of medium and fine sand, sometimes with a fraction of coarse sand, which remains damp throughout the tidal cycle and contains little organic matter. The sediment is often rippled and typically lacks an anoxic sub-surface layer. The infauna is dominated by burrowing amphipods, most notably Pontocrates arenarius, as well as Bathyporeia pelagica, Haustorius arenarius and the isopod Eurydice pulchra. The polychaete fauna is poor, dominated by Scolelepis squamata, which tolerates the exposed and mobile sediment conditions. The presence of polychaetes may be seen as coloured burrows running down from the surface of the sediment.

Situation

This biotope may be present on the lower shore, where BarSa, AmSco.Eur, or AmSco.Sco are present higher up. Where AmSco.Pon occurs on the mid shore in relatively sheltered conditions, Po may be present on the lower shore. Tal may be present where driftlines of fucoids and other debris occur on the upper shore.

Temporal variation

This biotope may change to AmSco.Eur, which is very similar in character, if P. arenarius decreases in abundance. Winter storms may reduce the number of or temporarily remove macroinvertebrates from exposed sandy beaches, with the sediment becoming re-colonised during the summer months.

Similar biotopes

LS.LSa.MoSa.AmSco.Eur Occurs in similar physical environments, under slightly more sheltered conditions, and tending to be present higher up on the shore. Infauna is more sparse, dominated by E. pulchra, with P. arenarius absent.
LS.LSa.FiSa.Po.Pful Occurs in more sheltered, occasionally estuarine, conditions, where sediments are more stable. The infauna is dominated by polychaete species, while burrowing amphipods occur less frequently.
LS.LSa.FiSa.Po.Aten Occurs in more sheltered conditions. The sediments are even more stable than in the case of Po.Pful and therefore support bivalves, especially Angulus tenuis, in addition to a range of polychaete species similar to the Po.Pful assemblage. Burrowing amphipods occur less frequently than in AmSco.Pon.

Characterising Species

Taxa	Typical Abundance	% Contribution to similarity	Abundance (no.²)
Scolelepis	A	3	22
Scolelepis squamata	C	11	39
Pontocrates arenarius	C	62	90
Bathyporeia pelagica	C	6	37
Haustorius arenarius	C	2	27
Eurydice pulchra	F	7	49

Example photographs of biotope

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This report should be cited as:
DAVID W. CONNOR, JAMES H. ALLEN, NEIL GOLDING, KERRY L. HOWELL, LOUISE M. LIEBERKNECHT, KATE O. NORTHEN AND JOHNNY B. REKER (2004)
The Marine Habitat Classification for Britain and Ireland Version 04.05 JNCC, Peterborough<
ISBN 1 861 07561 8 (internet version)
www.jncc.gov.uk/MarineHabitatClassification