Red List habitat classification > RL - Marine habitats > RLNEA - Atlantic > NEAA5.42 Estuarine Atlantic sublittoral mixed sediment

Estuarine Atlantic sublittoral mixed sediment

Quick facts

Red List habitat type code NEAA5.42
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)

Summary

This habitat comprises shallow sublittoral mixed sediments in estuarine conditions (18-35ppt), often with surface shells or stones, enabling the development of diverse epifaunal communities. There may be moderately strong (1-3kn) to negligible tidal streams. Wave exposure can vary from sheltered to extremely sheltered. This habitat typically occurs to depths of 10m. This habitat type is quite species rich, compared with more homogeneous sediments.

Indicators of quality:

Long term studies of many estuaries typically focus on the physical, biological and chemical characteristics. Indicators of quality of this habitat are frequently linked to those for the whole estuarine environment and therefore include morphological and physical characteristics, carrying capacity and water quality parameters. For the specific habitat, benthic indices, contaminant levels and productivity are some of the frequently used measures of quality.

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

This habitat has a widespread distribution (EOO >50,000 km2) and although not reported to occur in many locations (AOO <50) it is unlikely that the available data cover its full distribution. This habitat has therefore been assessed as Data Deficient both at the EU 28 and EU 28+ levels because of the lack of information on its extent and on any trends in quantity and quality.
EU
Red List Category Red List Criteria
Data Deficient
Europe
Red List Category Red List Criteria
Data Deficient

Confidence in the assessment

low
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Urbanisation, residential and commercial development
    • Discharges
  • Biological resource use other than agriculture & forestry
    • Fishing and harvesting aquatic resources
    • Professional active fishing
    • Benthic or demersal trawling
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Marine water pollution
    • Oil spills in the sea
    • Toxic chemical discharge from material dumped at sea
    • Non-synthetic compound contamination
    • Synthetic compound contamination
    • Radionucleide contamination
  • Natural System modifications
    • Human induced changes in hydraulic conditions
    • Removal of sediments (mud...)
    • Estuarine and coastal dredging
    • Modification of hydrographic functioning, general
    • Modification of water flow (tidal & marine currents)
    • Wave exposure changes
    • Alteration of sea-floor/ Water body morphology
    • Dykes, embankments, artificial beaches, general
    • Sea defense or coast protection works, tidal barrages
  • Climate change
    • Changes in abiotic conditions
    • Water flow changes (limnic, tidal and oceanic)
    • Wave exposure changes

Habitat restoration potential

Unknown

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. They include the removal of dykes, and water quality improvement programmes to reduce the risk of toxic contamination and to reduce nutrient inputs leading to eutrophication.
Spatial management including zoning of activities as part of Integrated Coastal Zone Management Schemes and Marine Protected Areas that cover the entire estuary complex, as well as water shed management, are beneficial.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
    • Restoring/Improving the hydrological regime
  • Measures related to spatial planning
    • Establish protected areas/sites
  • Measures related to hunting, taking and fishing and species management
    • Regulation/Management of fishery in marine and brackish systems
  • Measures related to urban areas, industry, energy and transport
    • Urban and industrial waste management

Distribution

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
Kattegat
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 244,272 >23 Unknown Based on a limited data set. AOO is known to be an underestimate.
EU28+ >23 Unknown Based on a limited data set. AOO is 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 Abra alba
Invertebrates Aphelochaeta marioni
Invertebrates Capitella capitata
Invertebrates Caulleriella zetlandica
Invertebrates Crepidula fornicata
Invertebrates Exogone naidina
Invertebrates Mediomastus fragilis
Invertebrates Nephtys hombergii
Invertebrates Tubificoides benedii
Species scientific name English common name Species group
Abra alba Invertebrates
Aphelochaeta marioni Invertebrates
Capitella capitata Invertebrates
Caulleriella zetlandica Invertebrates
Crepidula fornicata Invertebrates
Exogone naidina Invertebrates
Mediomastus fragilis Invertebrates
Nephtys hombergii Invertebrates
Tubificoides benedii Invertebrates

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
European Environment Agency (EEA)
Kongens Nytorv 6
1050 Copenhagen K
Denmark
Phone: +45 3336 7100