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	Annex I habitat types (EU Habitats Directive)
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

European Red List of Habitats categories

Based on Scientific Foundations for an IUCN Red List of Ecosystems

European Red List of Habitats criteria

Reduction in quantity (area of distribution)	A	A1 Present decline (over last 50 years) A2a Future decline (over the next 50 years) A2b Future/present decline (over a 50-year period inclunding present and future) A3 Historic decline
Restricted geographic distribution	B	B1 Restricted Extent of Occurrence (EOO) B2 Restricted Area of Occupancy (AOO) B3 Present at few locations
Reduction in abiotic quality	C	C/D1 Reduction in quality over the last 50 years C/D2 Reduction in quality in the future or in a period including present and future C/D3 Historic reduction in quality
Reduction in biotic quality	D
Quantitative analysis of probability of collapse	E

From Scientific Foundations for an IUCN Red List of Ecosystems

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

Not available

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	Large shallow inlets and bays	1160	Overlap	http://ec.europa.eu/environm...rective/index_en.htm
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	Reefs	1170	Overlap

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Sections

Communities of exposed Mediterranean lower mediolittoral rock

Quick facts

Summary

Threat status

Synthesis of Red List assessment

Confidence in the assessment

European Red List of Habitats categories

European Red List of Habitats criteria

Pressures and threats

Habitat restoration potential

Trends in extent

Average current trend in quantity

Trends in quality

Average current trend in quality

Conservation and management needs

List of conservation and management needs

Distribution

Geographic occurrence and trends

Extent of Occurrence, Area of Occupancy and habitat area

Characteristic species

Legal status

Relation to other habitat types mentioned in legal instruments

Vegetation types

Relation to vegetation types (syntaxa)

Other classifications