2. Données et outils
  3. Rechercher un habitat
  4. MB5-243 - Neomysis integer et Gammarus spp. dans du sable mobile de l'infralittoral en milieu à salinité faible et variable en Atlantique
  5. Description
MB5-243 - Neomysis integer et Gammarus spp. dans du sable mobile de l'infralittoral en milieu à salinité faible et variable en Atlantique

Neomysis integer and Gammarus spp. in fluctuating low salinity Atlantic infralittoral mobile sand
MB5-242 - Nephtys cirrosa et Limecola balthica dans du sable mobile de l'infralittoral en milieu à salinité variable en Atlantique

Classification des habitats EUNIS 2022

Descriptif de l'habitat

Upper estuary mobile fine muddy sands with very low fluctuating salinity characterised by the mysid shrimp Neomysis integer (see Arndt 1991) and amphipods of the genus Gammarus spp. This habitat has a rather sparse infauna and species such as N. integer will most likely be found on the sediment surface or just above it whilst Gammarus may be under loose weed, stones or other detritus on the sediment surface. The harsh physicochemical regime imposed by such environmental conditions in the upper estuary leads to a relatively impoverished community but high densities of the mobile, salinity-tolerant, crustaceans can occur. The biotope is found in the transitional zone between freshwater and brackish environments, relying on the decreased freshwater input during the summer for penetration of the brackish species up-stream. As such this biotope may also contain elements of freshwater communities.
Situation: It may be found in conjunction with MB6-257, although it lacks appreciable numbers of oligochaetes.
Temporal variation: Numbers of Neomysis may to fluctuate on a seasonal basis due high over wintering mortality (Gameson 1982) and the location of this biotope within the estuary may also shift upstream or downstream on a seasonal or yearly basis related in part to the freshwater flow into the estuary as has been noted in the Humber (Allen et al. 2003).

Bibliographie

European Topic Centre on Biological Diversity 2022. EUNIS marine habitat classification 2022 including crosswalks. Table Excel. (Source)