Red List habitat classification > RL - Marine habitats > RLNEA - Atlantic > NEAA5.12 Faunal communities in estuarine Atlantic sublittoral coarse sediment

Faunal communities in estuarine Atlantic sublittoral coarse sediment

Quick facts

Red List habitat type code NEAA5.12
Threat status
Europe Data Deficient
EU Data Deficient
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)


This habitat comprises clean gravels that occur in the upper reaches of marine inlets, especially estuaries, where water movement is sufficiently strong to remove the silt content of the sediment. It is one of the rarer habitat types to occur in estuaries. The gravel may be moved and reworked depending on tidal and river currents and may be infilled palaeo-river channels. The habitat typically lacks a significant seaweed component and is characterised by a sparse but very robust brackish water tolerant fauna. The epifauna of this habitat tends to be dominated by mobile predatory species. 

Indicators of quality:

Both biotic and abiotic indicators have been used to describe marine habitat quality. These include: the presence of characteristic species as well as those which are sensitive to the pressures the habitat may face; water quality parameters; levels of exposure to particular pressure, and more integrated indices which describe habitat structure and function, such as trophic index, or successional stages of development in habitats that have a natural cycle of change over time.

Indices developed to assess the ecological status of coastal waters, including estuaries, according to the Water Framework Directive, include physical indicators, water quality indicators and measures of benthic diversity, species richness and abundance. The latter group, which is particularly relevant to benthic habitats, includes a Benthic Quality Index, an Infaunal Trophic Index, a Marine Biotic index based on ecological groups, and the Benthic Opportunistic Polychaetes/Amphipods Index.

Characteristic species
For full habitat description, please download the habitat factsheet.

Threat status

Synthesis of Red List assessment

The data obtained from EMODnet suggests that this habitat could have an EOO<50,000 km2 and an AOO<20. However the distribution and extent is known to be substantially incomplete as known occurrences include widely separated locations such as the Gironde estuary, France, the Severn Estuary, UK and Odense fjord, Denmark. There is a lack of information on the extent of this habitat and any trends in quantity or quality over the last 50 years. No future trends have been estimated. For the purposes of Red List assessment it is therefore considered to be Data Deficient for both the EU 28 and EU 28+.
Red List Category Red List Criteria
Data Deficient -
Red List Category Red List Criteria
Data Deficient -

Confidence in the assessment

Red List of habitat categories and criteria descriptions

Pressures and threats

  • Urbanisation, residential and commercial development
    • Discharges
    • Disposal of household / Recreational facility waste
    • Disposal of industrial waste
    • Disposal of inert materials
    • Other discharges
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Pollution to surface waters by industrial plants
    • Pollution to surface waters by storm overflows
    • Other point source pollution to surface water
    • Diffuse pollution to surface waters via storm overflows or urban run-off
    • Diffuse pollution to surface waters due to agricultural and forestry activities

Habitat restoration potential


Trends in extent

Average current trend in quantity

Unknown Unknown
EU28 EU28+

Trends in quality

Average current trend in quality

Unknown Unknown
EU28 EU28+

Conservation and management needs

Conservation and management schemes to benefit estuarine habitats have been applied at a number of scales ranging from whole estuary systems to small areas within an estuary. Beneficial management measures for this habitat would mainly include water quality improvement programmes to reduce the risk of toxic contamination or nutrient inputs.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
  • Measures related to urban areas, industry, energy and transport
    • Urban and industrial waste management


For each habitat a distribution map was produced from a wide variety of sources indicating known and potential occurrences of the habitat in 10x10 km grids within Europe. Occurrences in grid cells were given in two classes: actual distribution from relatively reliable sources (surveys, expert knowledge), and potential distribution based on models or less reliable indicators. Please download the fact sheet to see the map.

Geographic occurrence and trends

Seas Present or presence uncertain Current area of habitat (Km2) Recent trend in quantity (last 50 years) Recent trend in quality (last 50 years)
Celtic Seas Present unknown Unknown Unknown
Greater North Sea
Bay of Biscay and the Iberian Coast

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 >45,297 >8 Unknown EOO and AOO figures are known to be an underestimate.
EU28+ >8 Unknown EOO and AOO figures are known to be an underestimate.
AOO = the area occupied by a habitat measured in number of 10x10 km grid cells.
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).

Characteristic species

The full list of characteristic species and genus are available above from the Summary. The species available in the EUNIS database are shown here.
Invertebrates Carcinus maenas
Species scientific name English common name Species group
Carcinus maenas Invertebrates

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
European Environment Agency (EEA)
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