EUNIS habitat classification 2017 > M - Marine benthic habitats > MA6 - Littoral mud > MA62 - Atlantic littoral mud > MA623 - Seagrass beds on Atlantic littoral mud > MA6231 - Zostera noltii beds on Atlantic littoral mud

Zostera noltii beds on Atlantic littoral mud

Quick facts

EUNIS habitat type code MA6231
Relation to Resolution 4 habitat type (used for designation of Emerald sites)

Description (English)

Mid and upper shore wave-sheltered muddy fine sand or sandy mud with narrow-leafed eel grass Zostera noltii at an abundance of frequent or above. It should be noted that the presence of Z. noltii as scattered fronds does not change what is otherwise a muddy sand biotope. Exactly what determines the distribution of Z. noltii is not entirely clear. It is often found in small lagoons and pools, remaining permanently submerged, and on sediment shores where the muddiness of the sediment retains water and stops the roots from drying out. An anoxic layer is usually present below 5 cm sediment depth. The infaunal community is characterised by the polychaetes Scoloplos armiger, Pygospio elegans and Arenicola marina, oligochaetes, the spire shell Hydrobia ulvae, and the bivalves Cerastoderma edule and Limecola balthica (Macoma balthica). The green algae Enteromorpha spp. may be present on the sediment surface. The characterising species lists below give an indication both of the epibiota and of the sediment infauna that may be present in intertidal seagrass beds. The biotope is described in more detail in the British National Vegetation Classification (see the chapter on saltmarsh communities in Rodwell, 2000).
Situation: Z. noltii is most frequently found on lower estuary and sheltered coastal muddy sands, together with biotopes such as unit MA5-252.
Temporal variation: There may be seasonal variation in the area covered by intertidal seagrass beds, as plants die back during cold temperatures in winter. Intertidal seagrass beds may also be subject to heavy grazing by geese, which can reduce the extent of the plant cover significantly. The rhizomes of the plants will remain in place within the sediment in both situations.

Source: EUNIS habitat classification

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Species mentioned in habitat description

Flowering Plants Zostera noltii
Invertebrates Arenicola marina
Invertebrates Cerastoderma edule
Invertebrates Hydrobia ulvae
Invertebrates Pygospio elegans
Invertebrates Scoloplos armiger
Species scientific name English common name Species group
Zostera noltii Flowering Plants
Arenicola marina Invertebrates
Cerastoderma edule Invertebrates
Hydrobia ulvae Invertebrates
Pygospio elegans Invertebrates
Scoloplos armiger Invertebrates

Other classifications

Classification Code Habitat type name Relationship type
EUNIS Habitat Classification 2007 (revised descriptions 2012) A2.6111 Zostera noltii beds in littoral muddy sand overlap
For relation to plant communities (syntaxa), see Vegetation types

History

Classification Code Habitat type name Relationship type Comment
EUNIS Habitat Classification 200410 A2.6111 Zostera noltii beds in littoral muddy sand same
EUNIS Habitat Classification 200308 A2.7111 Zostera noltii beds in littoral muddy sand same
EUNIS Habitat Classification 200202 A2.7111 Zostera noltii beds in upper to mid shore muddy sand same
EUNIS Habitat Classification 199910 A2.7111 Zostera noltii beds in upper to mid shore muddy sand same
MNCR BioMar 97.06 (Britain & Ireland) LMS.Zos.Znol Zostera noltii beds in upper to mid shore muddy sand same
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