Red List habitat classification > RL - Marine habitats > RLMED - Mediterranean > MEDA1.14 Communities of exposed Mediterranean lower mediolittoral rock

Communities of exposed Mediterranean lower mediolittoral rock

Quick facts

Red List habitat type code MEDA1.14
Threat status
Europe Data Deficient
EU Near Threatened
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)

Summary

This habitat develops on the lower horizon of the mediolittoral rock. Although never completely submerged for long periods of time, the rock surfaces are kept moist by spray from wave action. It occupies a zone of variable extent, generally immediately above mean sea level. The hard surfaces are colonised by encrusting and erect epifauna with the dominant species depending on the wave exposure and shape different associated biotopes which are dominated by encrusting species. The mussel Mytilus galloprovincialis may be frequent, especially where there are high levels of organic matter. Encrusting coralline algae (Lithophyllum spp.) are also characteristic of this habitat with different species dominating depending on the rock type and geographical area.

Indicators of quality.

Some of the coralline algae associated with this habitat may be potential indicators of pollution (e.g. Lithophyllum byssoides) and the abundance of Mytilus galloprovincialis can be linked to decrease in environmental quality. An quality index based on the presence and abundance of macroalgal communities is being used in Spanish Atlantic waters to report on similar habitats (CRF Index).

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

Threat status

Synthesis of Red List assessment

Despite most of the Mediterranean coast being rocky, studies on quantitative data are scarce. Nonetheless, given the past development of harbours, dikes and others coastal structures, and the known distribution of this habitat along the EU coastline, at estimated 25 % has been lost over the last 50 years. This habitat has therefore been assessed as Near Threatened under criterion A1 for the EU 28. For EU 28+, the habitat has a large EOO, and therefore it qualifies as Least Concern under Criterion B. However, the habitat is assessed as Data Deficient at EU 28+ level given the lack of information on its trends in quantity and quality and the fact that its overall distribution is unknown.
EU
Red List Category Red List Criteria
Near Threatened A1
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
    • Urbanised areas, human habitation
    • Discharges
    • Other urbanisation, industrial and similar activities
  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Nutrient enrichment (N, P, organic matter)
    • Marine water pollution
  • Natural System modifications
    • Human induced changes in hydraulic conditions

Habitat restoration potential

Many of the species associated with this habitat are robust and can recolonise rapidly.

Trends in extent

Average current trend in quantity

Decreasing Decreasing
EU28 EU28+

Trends in quality

Average current trend in quality

Unknown Unknown
EU28 EU28+

Conservation and management needs

This habitat is widespread and common and therefore likely to be present within some protected areas although it may not be subject to specific conservation measures. Beneficial actions include those which improve water quality, the regulation of coastal development in order to avoid both direct and indirect damage, and controls on the harvesting of the mussel Mytilus galloprovincialis.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
    • Restoring coastal areas
  • Measures related to spatial planning
    • Establish protected areas/sites
  • Measures related to hunting, taking and fishing and species management
    • Other species management measures

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)
Adriatic Sea Present Unknown Unknown Decreasing
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 2,000,004 367 Unknown EOO and AOO have been calculated on the available data. Although this data set is known to be incomplete the figures exceed the thresholds for threatened status.
EU28+ 474 Unknown EOO and AOO have been calculated on the available data. Although this data set is known to be incomplete the figures exceed the thresholds for threatened status.
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.
Algae Acrochaetium duboscqii
Algae Boergeseniella fruticulosa
Algae Bryopsis muscosa
Algae Callithamnion granulatum
Algae Ceramium ciliatum
Algae Ceramium diaphanum
Algae Corallina elongata
Algae Laurencia glandulifera
Algae Laurencia pyramidalis
Algae Lithophyllum byssoides
Algae Lithophyllum incrustans
Algae Nemoderma tingitanum
Algae Osmundea verlaquei
Algae Polysiphonia sertularioides
Algae Polysiphonia tripinnata
Algae Pseudolithoderma adriaticum
Algae Ralfsia verrucosa
Algae Ulva fasciata
Algae Ulva rigida
Invertebrates Chthamalus montagui
Invertebrates Chthamalus stellatus
Invertebrates Mytilaster minimus
Invertebrates Mytilus galloprovincialis
Invertebrates Patella ferruginea
Invertebrates Patella ulyssiponensis
Species scientific name English common name Species group
Acrochaetium duboscqii Algae
Boergeseniella fruticulosa Algae
Bryopsis muscosa Algae
Callithamnion granulatum Algae
Ceramium ciliatum Algae
Ceramium diaphanum Algae
Corallina elongata Algae
Laurencia glandulifera Algae
Laurencia pyramidalis Algae
Lithophyllum byssoides Algae
Lithophyllum incrustans Algae
Nemoderma tingitanum Algae
Osmundea verlaquei Algae
Polysiphonia sertularioides Algae
Polysiphonia tripinnata Algae
Pseudolithoderma adriaticum Algae
Ralfsia verrucosa Algae
Ulva fasciata Algae
Ulva rigida Algae
Chthamalus montagui Invertebrates
Chthamalus stellatus Invertebrates
Mytilaster minimus Invertebrates
Mytilus galloprovincialis Invertebrates
Patella ferruginea Invertebrates
Patella ulyssiponensis 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