Eelgrass (Zostera noltii) beds



GB distribution

Compiled by: Leigh Jones, Joint Nature Conservation Committee, Monkstone House, City Road, Peterborough PE1 IJY, UK.

Derived, in part, from: the UK marine biotope classification (Connor et al. 1997a) and a review undertaken for the UK Marine SACs Project (Davison 1998).


Classification Code Biotope(s)
Europe (EUNIS Nov. 1999) A2.71/B-LMS.Zos.Znol Zostera noltii beds in upper to mid shore muddy sand
Wadden Sea 05.02.01 Intertidal seagrass beds
Britain/Ireland (MNCR BioMar 97.06) LMS.Znol Zostera noltii beds in upper to mid shore muddy sand
France (ZNIEFF-MER) II.3.3



Herbiers de Zostera marina, Zostera noltii (= Z. nana pro parte) du médiolittoral inférieur

Biocenose des sables vaseux superficiels de mode calme (SVMC)


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. This is similar to polychaetes and Cerastoderma edule (LMS.PCer) since it is most frequently found on lower estuary and sheltered coastal muddy sands with a similar infauna. Exactly what determines the distribution of the Zostera noltii is, however, not entirely clear. Zostera noltii 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. A black layer is usually present below 5 cm sediment depth. The infaunal community is characterised by polychaetes Pygospio elegans and Arenicola marina, mud amphipods Corophium volutator and bivalves Cerastoderma edule, Macoma balthica and Scrobicularia plana. Typically an epifaunal community is found that includes the mud snail Hydrobia ulvae, shore crabs Carcinus maenas and the green alga Enteromorpha sp. This biotope should not be confused with IMS.Zmar, which is a Zostera marina bed on the lower shore or shallow sublittoral clean or muddy sand.

GB distribution

(from MNCR database in February 1999)













Habitat requirements

Species composition and biodiversity

Ecological relationships

Sensitivity to human activities

Conservation and protection status