Seagrass beds on Atlantic littoral mud

Description (English)

Mid and upper shore wave-sheltered muddy fine sand or sandy mud can have high densities of Zostera noltei (formerly known as Z.noltii or Z.nana) and/or Z.marina. Z.noltei forms stands with a cover of delicate trailing narrow leaves up to about 20 cm long. It survives the winter as rhizomes, therefore the locations remain stable over many years. It may occur monospecific, or with Z. marina or Ruppia spp. and occasional plants of lower salt-marsh species such as annual Salicornia spp. or Spartina anglica, as stands of Z. noltei may not only pass downshore to Z. marina but also to communities of the lower saltmarsh.
There may be seasonal variation in the area covered by intertidal seagrass beds, as plants die back 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 Z.noltei will remain in place within the sediment in both situations and plants towards the lower limit may remain winter-green.

Source: EUNIS habitat classification