Red List habitat classification > RL - Marine habitats > RLMED - Mediterranean > MEDA5.38 Communities of Mediterranean infralittoral muddy detritic bottoms

Communities of Mediterranean infralittoral muddy detritic bottoms

Quick facts

Red List habitat type code MEDA5.38
Threat status
Europe Vulnerable
EU Vulnerable
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)


This habitat develops in areas where a detritus bottom is covered with mud formed by terrigenous deposits from rivers. The sediment is a very muddy sand or sandy mud, or even a rather compacted mud, rich in shell debris or volcanic fragments (scoriae); sedimentation is slow enough to allow the development of sessile epifauna. Gravel, sand and mud are mixed in varying quantities, but mud always predominates. In some geographical areas, this habitat is characterized by facies with the brittlestar Ophiothrix quinquemaculata (Ophiuroidea) that extends to the circalittoral. This species in some places forms an extremely dense population which is almost 90% ophiuran.

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.

There are no commonly agreed indicators of quality for this habitat, although particular parameters may have been set in certain situations e.g. protected features within Natura 2000 sites, where reference values have been determined and applied on a location-specific basis.

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

Threat status

Synthesis of Red List assessment

This habitat has a large natural range in the Mediterranean region. The precise extent is unknown however as EOO >50,000km2 , this exceeds the thresholds for a threatened category on the basis of restricted geographic distribution. The AOO is unknown and trends in the extent are also unknown at present. This habitat is directly subject to various anthropogenic impacts resulting from urban, industrial, agricultural, aquaculture and other coastal activities as well as the impact of demersal fishing gears. The analysis conducted within this zone showed that human activities had a substantial reduction on this habitat and that severe degradation is an ongoing process, and so it is reasonable to assume that quality of this habitat has severly declined in the majority of areas of the Mediterranean (intermediate declining affecting at least 50% of the habitat extent). This habitat has therefore been assessed as Vulnerable under criteria C/D1.
Red List Category Red List Criteria
Vulnerable C/D1
Red List Category Red List Criteria
Vulnerable C/D1

Confidence in the assessment

Red List of habitat categories and criteria descriptions

Pressures and threats

  • Agriculture
    • Use of biocides, hormones and chemicals
    • Fertilisation
  • Urbanisation, residential and commercial development
    • Urbanised areas, human habitation
    • Industrial or commercial areas
    • Discharges
  • Biological resource use other than agriculture & forestry
    • Marine and Freshwater Aquaculture
    • Fishing and harvesting aquatic resources
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Marine water pollution
    • Soil pollution and solid waste (excluding discharges)

Habitat restoration potential


Trends in extent

Average current trend in quantity

Unknown Unknown
EU28 EU28+

Trends in quality

Average current trend in quality

Decreasing Decreasing
EU28 EU28+

Conservation and management needs

There are a variety of fisheries regulations that are relevant to the conservation of this habitat type. In particular the use of towed gears (trawls, dredges etc,) has recently been prohibited within 3 nautical miles of the coast or within the 50 m isobath where that depth is reached at a shorter distance from the coast. Spatial planning, regulation of discharges to the marine environment and marine protected areas may also benefit this habitat. Direct engagement of stakeholders in the planning of the management process, analysis of social and economic costs and benefits of different management options, will be essential for the successful implementation of conservation actions.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
  • Measures related to marine habitats
    • Restoring marine habitats
  • Measures related to spatial planning
    • Other marine-related measures
    • 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


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)
Adriatic Sea Present Unknown Decreasing Unknown
Aegian-Levantine Sea
Ionian Sea and the Central Mediterranean Sea
Western Mediterranean Sea

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 >50,000 unknown Unknown There is insufficient quantitative data to make an accurate estimate of EOO and AOO.
EU28+ unknown Unknown There is insufficient quantitative data to make an accurate estimate of EOO and AOO.
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

Not available

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
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