Description of biotope or habitat type
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Zostera marina/angustifolia beds on lower shore or infralittoral clean or muddy sand
Physical habitat description
| Salinity | Full (30-35 ppt), Variable (18-35 ppt) |
|---|---|
| Wave exposure | Moderately exposed, Sheltered, Very sheltered, Extremely sheltered |
| Tidal streams | Moderately strong (1-3 kn), Weak (>1 kn), Very weak (negligible) |
| Substratum | Clean sand to muddy fine sand or mud |
| Zone | Infralittoral |
| Depth Band | 0-5 m, 5-10 m, Lower shore |
| Other Features |
Biotope origin
| Derived using data from | Various |
| Faunal group | Epifauna |
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.
- Records used to define the biotope (core records)
- Other records assigned to this biotope, marked as 'certain'
- Other records assigned to this biotope, marked as 'uncertain'
- Predicted extent of the level 3 (for sublittoral rock & deep sea) or 4 (for sublittoral sediment) habitat
Point data based on records in the UK Marine Recorder Snapshot. Predicted habitat extent is from UKSeaMap.
Description
Expanses of clean or muddy fine sand and sandy mud in shallow water and on the lower shore (typically to about 5 m depth) can have dense stands of Zostera marina/angustifolia [Note: the taxonomic status of Z. angustifolia is currently under consideration]. In SS.Smp.SSgr.Zmar the community composition may be dominated by these Zostera species and therefore characterised by the associated biota. Other biota present can be closely related to that of areas of sediment not containing Zostera marina, for example, Saccharina latissima, Chorda filum and infaunal species such as Ensis spp. and Echinocardium cordatum (e.g. Bamber 1993). From the available data it would appear that a number of sub-biotopes may be found within this biotope dependant on the nature of the substratum and it should be noted that sparse beds of Zostera marina may be more readily characterised by their infaunal community. For example, coarse marine sands with seagrass have associated communities similar to SS.SCS.ICS.MoeVen, SS.SCS.ICS.SLan or SS.SCS.ICS.Glap whilst muddy sands may have infaunal populations related to SS.SSa.IMuSa.EcorEns, SS.SMu.IMuSa.AreISa and SS.SSa.IMuSa.FfabMag. Muddy examples of this biotope may show similarities to SS.SMu.ISaMu.CundAasp, SS.SMu.IFiMu.PhiVir, SS.SMu.IFiMu.Are or SS.SMu.CSaMu.AfilKurAnit. At present the data does not permit a detailed description of these sub-biotopes but it is likely that with further study the relationships between these assemblages will be clarified. Furthermore, whilst the Zostera biotope may be considered an epibiotic overlay of established sedimentary communities it is likely that the presence of Zostera will modify the underlying community to some extent. For example, beds of this biotope in the south-west of Britain may contain conspicuous and distinctive assemblages of Lusitanian fauna such as Laomedea angulata, Hippocampus spp. and Stauromedusae. In addition, it is known that seagrass beds play an important role in the trophic status of marine and estuarine waters, acting as an important conduit or sink for nutrients and consequently some examples of Zostera marina beds have markedly anoxic sediments associated with them.
Situation
No situation data available.
Temporal variation
No temporal data available.
Characterising species
| Taxon | Relative importance of taxon for defining this community (%) | Typical abundance - SACFOR scale | % of core records where taxon was recorded |
|---|---|---|---|
| Zostera marina | 52 | Abundant | 81-100% |
| Corophium volutator | 9 | Abundant | 21-40% |
| Nemertea | 6 | Common | 41-60% |
| Nematoda | 5 | Common | 21-40% |
| Scoloplos armiger | 5 | Abundant | 41-60% |
| Chorda filum | 4 | Frequent | 21-40% |
| Tubificoides benedii | 4 | Frequent | 21-40% |
| Ampelisca brevicornis | 3 | Frequent | 21-40% |
| Anemonia viridis | 3 | Occasional | 21-40% |
| Arenicola marina | 3 | Occasional | 21-40% |
| Carcinus maenas | 3 | Occasional | 41-60% |
| Chironomidae | 3 | Abundant | 1-20% |
| Fabulina fabula | 3 | 21-40% | |
| Baltidrilus costatus | 3 | Super abundant | 1-20% |
| Lanice conchilega | 3 | Occasional | 21-40% |
| Kurtiella bidentata | 3 | Common | 21-40% |
| Platynereis dumerilii | 3 | Frequent | 21-40% |
| Pygospio elegans | 3 | Frequent | 21-40% |
| Abra alba | 2 | Common | 21-40% |
| Asterias rubens | 2 | Occasional | 21-40% |
| Nototropis swammerdamei | 2 | 21-40% | |
| Capitella capitata | 2 | Common | 21-40% |
| Dexamine spinosa | 2 | Frequent | 21-40% |
| Parexogone hebes | 2 | 21-40% | |
| Tritia reticulata | 2 | Occasional | 21-40% |
| Saccharina latissima | 2 | Occasional | 21-40% |
| Notomastus latericeus | 2 | 21-40% | |
| Pagurus bernhardus | 2 | Occasional | 21-40% |
| Spio filicornis | 2 | Frequent | 21-40% |
| Thyasira flexuosa | 2 | 1-20% | |
| Urothoe elegans | 2 | 21-40% | |
| Ulva | 2 | Occasional | 21-40% |
| Idotea balthica | 1 | 21-40% | |
| Oligochaeta | 1 | Frequent | 21-40% |
| Amphipholis squamata | 1 | Abundant | 21-40% |
| Apseudopsis latreillii | 1 | Frequent | 21-40% |
| Dexamine thea | 1 | Frequent | 21-40% |
| Euclymene oerstedii | 1 | Common | 1-20% |
| Steromphala cineraria | 1 | Occasional | 21-40% |
| Mediomastus fragilis | 1 | Common | 21-40% |
| Spiophanes bombyx | 1 | 21-40% |
Similar biotopes or habitat types
SS.SSa.IMuSa.EcorEns
The overlap between these two biotopes requires examinationClassification history of this biotope or habitat type
| Classification version | Code | Habitat name |
|---|---|---|
| 2015 (15.03) | SS.SMp.SSgr.Zmar | Zostera marina/angustifolia beds on lower shore or infralittoral clean or muddy sand |
| 2004 (04.05) | SS.SMp.SSgr.Zmar | Zostera marina/angustifolia beds on lower shore or infralittoral clean or muddy sand |
| 1997 (97.06) | SS.IMS.Sgr.Zmar | Zostera marina/angustifolia beds in lower shore or infralittoral clean or muddy sand |
| 1996 (6.95) | SS.IMS.ZmarBv | |
| 1995 | LMSND.ZOS |