Polychaete/bivalve-dominated mid estuarine mud shores
Description (English)
Mid estuarine shores of fine sediment, mostly in the silt and clay fraction (particle size less than 0.063 mm in diameter), though sandy mud may contain up to 40% sand (mostly very fine and fine sand). Littoral mud typically forms extensive mudflats, though dry compacted mud can form steep and even vertical structures, particularly at the top of the shore adjacent to saltmarshes. Little oxygen penetrates these cohesive sediments, and an anoxic layer is often present within millimetres of the sediment surface. Most mid estuarine muddy shores are subject to some freshwater influence, though at some locations more or less fully marine conditions may prevail. Mid estuarine muds support rich communities characterised by polychaetes, bivalves and oligochaetes.
Situation: Principally along mid estuarine shores. The mid estuarine communities may also be present in sheltered inlets, straits and embayments which are not part of major estuarine systems, though usually there is some freshwater influence.
Temporal variation: Enteromorpha spp. and Ulva lactuca may form mats on the surface of the mud during the summer months, particularly in areas of nutrient enrichment or where there is significant freshwater influence.
Source: EUNIS habitat classification
Quick facts
EUNIS habitat type | code A2.31 |
---|---|
Bern Convention | Included in a Resolution 4 habitat type at a higher level (A2.3) |
Relation to | Annex I habitat types (EU Habitats Directive) |
Legal status
Relation to other habitat types mentioned in legal instruments
Legal text | Annex | Name in legal text | Code in legal text |
Habitat type relationship |
More information |
---|---|---|---|---|---|
Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora - consolidated version 01/01/2007 | Annex I: natural habitat types of community interest whose conservation requires the designation of special areas of conservation | Mudflats and sandflats not covered by seawater at low tide | 1140 | Narrower | http://ec.europa.eu/environm...rective/index_en.htm |
Vegetation types
Relation to vegetation types (syntaxa)
Not availableSpecies mentioned in habitat description
Other classifications
Classification | Code | Habitat type name | Relationship type |
---|---|---|---|
Marine Habitat Classification Britain/Ireland 0405 | LS.LMu.MEst | Polychaete/bivalve-dominated mid estuarine mud shores | source |
CORINE Land Cover | 4.2.3. | Intertidal flats | n/a |
Barcelona Convention 199812 | II.1.1. | Biocenosis of muddy sands and muds | overlap |
History
Classification | Code | Habitat type name | Relationship type |
---|---|---|---|
EUNIS Habitat Classification 200410 | A2.31 | Polychaete/bivalve-dominated mid estuarine mud shores | same |
EUNIS Habitat Classification 200308 | A2.36 | Polychaete/bivalve-dominated mid estuarine mud shores | same |
EUNIS Habitat Classification 200202 | A2.36 | Sandy mud shores | same |
EUNIS Habitat Classification 199910 | A2.31 | Sandy mud shores | same |
EUNIS Habitat Classification 199811 | A2.31 | Invertebrate communities of sandy mud shores | same |
EUNIS Habitat Classification 199712 | A2.31 | Invertebrate communities of sandy mud shores | same |
MNCR BioMar 97.06 (Britain & Ireland) | LMU.SMu | Sandy mud shores | same |
MNCR BioMar 96.7 (Britain & Ireland) | LMU.SMu | same |