Biodiversity & Conservation

Zostera marina/angustifolia beds in lower shore or infralittoral clean or muddy sand



Image Keith Hiscock - Current swept bed of Zostera marina. Image width ca 2 m in foreground.
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Distribution map

SS.SMp.SSgr.Zmar recorded (dark blue bullet) and expected (light blue bullet) distribution in Britain and Ireland (see below)

  • Berne
  • EC_Habitats
  • UK_BAP

Marine natural heritage importance

Listed under EC Habitats Directive
UK Biodiversity Action Plan
National importance Uncommon
Habitat Directive feature (Annex 1) Mudflats and sandflats not covered by seawater at low tide
Sandbanks which are slightly covered by sea water all the time
Large shallow inlets and bays

Biotope importance

Intertidal and probably shallow subtidal Zostera marina beds provide food for a variety of wildfowl. Brent and Canadian geese rely on Zostera marina for a large proportion of their food. Declines in Brent geese and wigeon parallel the decline of Zostera marina. Little evidence to support the hypothesis that Zostera marina beds are nursery areas for fish


  • Seagrass beds are often associated with cockle beds. Suction dredging for bivalves, such as cockles and Mercenaria sp., has been reported to damage eelgrass beds (Davison & Hughes, 1998).
  • The decline in seagrass beds in the 1920s and1930s together with their importance in coastal processes has resulted in scientific research use and experimental management studies.
  • Seagrasses have been put to a number of uses world-wide, for example, sound-proofing, insulation, roofing thatch, binding soil, packaging, basket weaving and in the manufacture of 'coir' matting.

Additional information icon Additional information

The presence of seagrass beds reduces water flow and increases sedimentation in their locality and may be important in coastal defense. Their loss may increase wave energy reaching the shore and accelerate erosion. Zostera marina is also protected under the Berne convention.

This review can be cited as follows:

Tyler-Walters, H. & Wilding, C.M. 2008. Zostera marina/angustifolia beds in lower shore or infralittoral clean or muddy sand. Marine Life Information Network: Biology and Sensitivity Key Information Sub-programme [on-line]. Plymouth: Marine Biological Association of the United Kingdom. [cited 28/11/2015]. Available from: <>