Red List habitat classification > RL - Marine habitats > RLMED - Mediterranean > MEDA5.6x Infralittoral biogenic habitats in the Mediterranean - corralligenous bioconcretions

Infralittoral biogenic habitats in the Mediterranean - corralligenous bioconcretions

Quick facts

Red List habitat type code MEDA5.6x
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

Coralligenous habitats are hard bottoms of biogenic origin mainly produced by the accumulation of calcareous encrusting algae growing in dim light conditions. Although more extended in the circalittoral zone, they can also develop in the infralittoral zone, provided that light is dim enough to allow growth of the coralline algae that produce the build-up; therefore, infralittoral coralligenous concretions always develop in almost vertical walls, deep channels, or overhangs, and occupy reduced surfaces.

Coralligenous bioconcretions are always very complex in structure allowing the development of several kinds of communities including those dominated by living algae (on the upper part of the concretions), suspension feeders (upper and lower part of the concretions, wall cavities, and overhangs of the build-up), borers (inside the concretions), and even soft-bottom fauna (in the sediment deposited in cavities and holes).

This is a highly variable habitat that can be subdivided into different sub-habitats with different dominant species. For example coralligenous outcrops dominated;by Halimeda tuna and Mesophyllum spp. usually between 15 and 45 meters depth; by Peyssonnelia rosa-marina and other Peyssonneliaceae and Flabellia petiolata, in places with high sedimentation rates; on walls with Eunicella cavolini, in places with strong currents, between 15 and 40 meters depth; by Alcyonium acaule, in relatively shallow waters (15 to 45 meters depth) subjected to strong currents; and by Eunicella verrucosa, in places with high sedimentation rates.

Indicators of quality:                                                                                                         Several indicators have been proposed to assess the health of coralligenous habitats based on the composition and abundance of species (biotic cover and conspicuous species richness), the percent cover of different benthic assemblages (encrusting calcified Rhodophyta, non-calcified encrusting algae and fauna, turf forming algae, and sediment), boring species marks, percent cover of each species and the percentage of necrosis, bryozoa percent cover, sludge percent cover and the builder species percent cover.

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

Threat status

Synthesis of Red List assessment

This is a widespread habitat throughout the Mediterranean Sea. Country information and literature show an ongoing decline in quality due to warming, fishing activities, water quality and invasive species. There are no evidences of a general decline in quantity in the country information, however, taking into account the impacts this habitat is submitted to and further evidence and decreases decribed in the literature, it must be considered that quantity decreases have happened. Both quality and quantity decreases are expected to continue in the future. Taking into consideration the decline in habitat extent and quality the habitat is classified as Near Threatened for EU 28 and Data Deficient for EU 28+.
Given the future climate change scenarios for the Mediterranean, the decline of some of the structural species and the ongoing impacts, it is suggested a revision of the assessment in 5-10 years time to provide more quantitative evidences as the habitat is close to Vulnerable status criteria.
EU
Red List Category Red List Criteria
Near Threatened A1, A2a, A2b, C/D1
Europe
Red List Category Red List Criteria
Data Deficient -

Confidence in the assessment

medium
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Urbanisation, residential and commercial development
    • Urbanised areas, human habitation
  • Biological resource use other than agriculture & forestry
    • Fishing and harvesting aquatic resources
    • Professional passive fishing
    • Professional active fishing
  • Pollution
    • Marine water pollution
  • Invasive, other problematic species and genes
    • Invasive non-native species
  • Climate change
    • Changes in abiotic conditions
    • Temperature changes (e.g. rise of temperature & extremes)
    • pH-changes
    • Habitat shifting and alteration
    • Decline or extinction of species

Habitat restoration potential

The effect of disturbances in coralligenous assemblages is poorly understood, and there are no data at all on the capacity of this environment to recover (with the exception of fish stocks after fishing ban). However, as the most abundant and structuring species of coralligenous habitats are long-lived and slow-growing species with limited recruitment rates, and native and non-native species can rapidily colonise the structures, local recover can be difficult and extremely slow.

Trends in extent

Average current trend in quantity

Decreasing Decreasing
EU28 EU28+

Trends in quality

Average current trend in quality

Decreasing Decreasing
EU28 EU28+

Conservation and management needs

Besides the designation of protected areas and fisheries reserves, specific measures aimed at protecting the coralligenous environment might include the following: Improvements in water quality, the prohibition of trawling in areas with coralligenous outcrops and their vicinity and management of traditional and recreational fisheries to prevent stock depletion of target fish and crustaceans.

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
    • Establish protected areas/sites
    • Legal protection of habitats and species

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 147,102 Decreasing 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 2,483,265 1,913 137,180 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+ 2,100 147,102 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 Aeodes marginata
Algae Aglaothamnion tripinnatum
Algae Amphiroa beauvoisii
Algae Balliella cladoderma
Algae Bonnemaisonia asparagoides
Algae Botryocladia chiajeana
Algae Codium coralloides
Algae Contarinia squamariae
Algae Cryptonemia lomation
Algae Cystoseira zosteroides
Algae Dictyopteris polypodioides
Algae Erythroglossum balearicum
Algae Erythroglossum sandrianum
Algae Eupogodon planus
Algae Flabellia petiolata
Algae Gloiocladia furcata
Algae Gulsonia nodulosa
Algae Halimeda tuna
Algae Halopteris filicina
Algae Kallymenia feldmannii
Algae Kallymenia lacerata
Algae Kallymenia patens
Algae Kallymenia requienii
Algae Lomentaria subdichotoma
Algae Mesophyllum alternans
Algae Microdictyon tenuius
Algae Myriogramme tristromatica
Algae Neogoniolithon mamillosum
Algae Nereia filiformis
Algae Neurocaulon foliosum
Algae Osmundaria volubilis
Algae Palmophyllum crassum
Algae Peyssonnelia bornetii
Algae Peyssonnelia harveyana
Algae Peyssonnelia rosa-marina
Algae Peyssonnelia rubra
Algae Peyssonnelia squamaria
Algae Phyllariopsis brevipes
Algae Phyllophora crispa
Algae Predaea ollivieri
Algae Ptilophora mediterranea
Algae Rhodophyllis divaricata
Algae Rodriguezella bornetii
Algae Rodriguezella pinnata
Algae Schmitzia neapolitana
Algae Sebdenia monardiana
Algae Sebdenia rodrigueziana
Algae Seirospora giraudyi
Algae Sphaerococcus rhizophylloides
Algae Valonia macrophysa
Fishes Acantholabrus palloni
Fishes Anthias anthias
Fishes Conger conger
Fishes Coris julis
Fishes Epinephelus marginatus
Fishes Gobius kolombatovici
Fishes Gobius vittatus
Fishes Labrus mixtus
Fishes Lappanella fasciata
Fishes Muraena helena
Fishes Pagrus pagrus
Fishes Phycis phycis
Fishes Sciaena umbra
Fishes Scorpaena scrofa
Fishes Scyliorhinus canicula
Fishes Serranus cabrilla
Fishes Zeus faber
Invertebrates Adeonella calveti
Invertebrates Agelas oroides
Invertebrates Alcyonium acaule
Invertebrates Anseropoda placenta
Invertebrates Antedon mediterranea
Invertebrates Aplidium conicum
Invertebrates Aplidium elegans
Invertebrates Aplysina cavernicola
Invertebrates Astroides calycularis
Invertebrates Axinella cannabina
Invertebrates Axinella damicornis
Invertebrates Axinella polypoides
Invertebrates Axinella verrucosa
Invertebrates Bolma rugosa
Invertebrates Bugula calathus
Invertebrates Cellaria salicornioides
Invertebrates Charonia lampas
Invertebrates Chartella tenella
Invertebrates Clathrina clathrus
Invertebrates Corallium rubrum
Invertebrates Crella elegans
Invertebrates Cystodytes dellechiajei
Invertebrates Dendrophyllia ramea
Invertebrates Dysidea avara
Invertebrates Echinus melo
Invertebrates Eunicella cavolini
Invertebrates Eunicella singularis
Invertebrates Eunicella verrucosa
Invertebrates Filograna implexa
Invertebrates Galathea strigosa
Invertebrates Gerardia savaglia
Invertebrates Hemimycale columella
Invertebrates Holothuria forskali
Invertebrates Homarus gammarus
Invertebrates Hornera frondiculata
Invertebrates Leptopsammia pruvoti
Invertebrates Lithophaga lithophaga
Invertebrates Microcosmus sabatieri
Invertebrates Ophiothrix fragilis
Invertebrates Palinurus elephas
Invertebrates Paralcyonium spinulosum
Invertebrates Paramuricea clavata
Invertebrates Parazoanthus axinellae
Invertebrates Pentapora fascialis
Invertebrates Petrosia ficiformis
Invertebrates Phyllangia mouchezii
Invertebrates Pilumnus hirtellus
Invertebrates Platydoris argo
Invertebrates Pleraplysilla spinifera
Invertebrates Pleurobranchus testudinarius
Invertebrates Protula tubularia
Invertebrates Pseudodistoma cyrnusense
Invertebrates Pteria hirundo
Invertebrates Raspaciona aculeata
Invertebrates Reniera fulva
Invertebrates Reteporella feuerbornii
Invertebrates Reteporella grimaldii
Invertebrates Rhynchozoon neapolitanum
Invertebrates Salmacina dysteri
Invertebrates Schizomavella linearis
Invertebrates Schizomavella mamillata
Invertebrates Scyllarides latus
Invertebrates Serpula vermicularis
Invertebrates Smittina cervicornis
Invertebrates Spirastrella cunctatrix
Invertebrates Spondylus gaederopus
Invertebrates Turbicellepora avicularis
Invertebrates Umbraculum umbraculum
Species scientific name English common name Species group
Aeodes marginata Algae
Aglaothamnion tripinnatum Algae
Amphiroa beauvoisii Algae
Balliella cladoderma Algae
Bonnemaisonia asparagoides Algae
Botryocladia chiajeana Algae
Codium coralloides Algae
Contarinia squamariae Algae
Cryptonemia lomation Algae
Cystoseira zosteroides Algae
Dictyopteris polypodioides Algae
Erythroglossum balearicum Algae
Erythroglossum sandrianum Algae
Eupogodon planus Algae
Flabellia petiolata Algae
Gloiocladia furcata Algae
Gulsonia nodulosa Algae
Halimeda tuna Algae
Halopteris filicina Algae
Kallymenia feldmannii Algae
Kallymenia lacerata Algae
Kallymenia patens Algae
Kallymenia requienii Algae
Lomentaria subdichotoma Algae
Mesophyllum alternans Algae
Microdictyon tenuius Algae
Myriogramme tristromatica Algae
Neogoniolithon mamillosum Algae
Nereia filiformis Algae
Neurocaulon foliosum Algae
Osmundaria volubilis Algae
Palmophyllum crassum Algae
Peyssonnelia bornetii Algae
Peyssonnelia harveyana Algae
Peyssonnelia rosa-marina Algae
Peyssonnelia rubra Algae
Peyssonnelia squamaria Algae
Phyllariopsis brevipes Algae
Phyllophora crispa Algae
Predaea ollivieri Algae
Ptilophora mediterranea Algae
Rhodophyllis divaricata Algae
Rodriguezella bornetii Algae
Rodriguezella pinnata Algae
Schmitzia neapolitana Algae
Sebdenia monardiana Algae
Sebdenia rodrigueziana Algae
Seirospora giraudyi Algae
Sphaerococcus rhizophylloides Algae
Valonia macrophysa Algae
Acantholabrus palloni Scale-rayed wrasse Fishes
Anthias anthias Sea perch Fishes
Conger conger Conger Fishes
Coris julis African rainbow wrasse Fishes
Epinephelus marginatus Dusky grouper Fishes
Gobius kolombatovici Fishes
Gobius vittatus Striped goby Fishes
Labrus mixtus Cuckoo wrasse Fishes
Lappanella fasciata Fishes
Muraena helena Marbled moray Fishes
Pagrus pagrus Common seabream Fishes
Phycis phycis Forkbeard Fishes
Sciaena umbra Brown meagre Fishes
Scorpaena scrofa Large-scaled scorpion fish Fishes
Scyliorhinus canicula Dogfish Fishes
Serranus cabrilla Comber Fishes
Zeus faber Atlantic John dory Fishes
Adeonella calveti Invertebrates
Agelas oroides Invertebrates
Alcyonium acaule Invertebrates
Anseropoda placenta Invertebrates
Antedon mediterranea Invertebrates
Aplidium conicum Invertebrates
Aplidium elegans Invertebrates
Aplysina cavernicola Invertebrates
Astroides calycularis Invertebrates
Axinella cannabina Invertebrates
Axinella damicornis Invertebrates
Axinella polypoides Invertebrates
Axinella verrucosa Invertebrates
Bolma rugosa Invertebrates
Bugula calathus Invertebrates
Cellaria salicornioides Invertebrates
Charonia lampas Invertebrates
Chartella tenella Invertebrates
Clathrina clathrus Invertebrates
Corallium rubrum Invertebrates
Crella elegans Invertebrates
Cystodytes dellechiajei Invertebrates
Dendrophyllia ramea Invertebrates
Dysidea avara Invertebrates
Echinus melo Invertebrates
Eunicella cavolini Invertebrates
Eunicella singularis Invertebrates
Eunicella verrucosa Invertebrates
Filograna implexa Invertebrates
Galathea strigosa Invertebrates
Gerardia savaglia Invertebrates
Hemimycale columella Invertebrates
Holothuria forskali Invertebrates
Homarus gammarus Invertebrates
Hornera frondiculata Invertebrates
Leptopsammia pruvoti Invertebrates
Lithophaga lithophaga Invertebrates
Microcosmus sabatieri Invertebrates
Ophiothrix fragilis Invertebrates
Palinurus elephas Invertebrates
Paralcyonium spinulosum Invertebrates
Paramuricea clavata Invertebrates
Parazoanthus axinellae Invertebrates
Pentapora fascialis Invertebrates
Petrosia ficiformis Invertebrates
Phyllangia mouchezii Invertebrates
Pilumnus hirtellus Invertebrates
Platydoris argo Invertebrates
Pleraplysilla spinifera Invertebrates
Pleurobranchus testudinarius Invertebrates
Protula tubularia Invertebrates
Pseudodistoma cyrnusense Invertebrates
Pteria hirundo Invertebrates
Raspaciona aculeata Invertebrates
Reniera fulva Invertebrates
Reteporella feuerbornii Invertebrates
Reteporella grimaldii Invertebrates
Rhynchozoon neapolitanum Invertebrates
Salmacina dysteri Invertebrates
Schizomavella linearis Invertebrates
Schizomavella mamillata Invertebrates
Scyllarides latus Invertebrates
Serpula vermicularis Invertebrates
Smittina cervicornis Invertebrates
Spirastrella cunctatrix Invertebrates
Spondylus gaederopus Invertebrates
Turbicellepora avicularis Invertebrates
Umbraculum umbraculum 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