Red List habitat classification > RL - Marine habitats > RLMED - Mediterranean > MEDA5.52B Algal dominated communities in the Mediterranean infralittoral sediment

Algal dominated communities in the Mediterranean infralittoral sediment

Quick facts

Red List habitat type code MEDA5.52B
Threat status
Europe Endangered
EU Endangered
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 infralittoral sediment covered by algae in sheltered places and where organic matter enhances macroalgal growth. Different sub-habitats that can be distinguished by the dominant species composition and the environment they colonize. These include  Caulerpa prolifera,  Acetabularia calyculus, growing on dead shells of cockles and other clams; Penicillus capitatus, usually on sediments covering dead rhizomes of Posidonia oceanica as well as Valonia aegagropila, Rytiphlaea tinctoria or Alsidium corallinum, Ulva spp., Cladophora spp. and Gracilaria spp. The habitat is also very variable depending on nutrients, sedimentation, temperature, salinity, and hydrodynamism. 

Indicators of quality:                                                                                                                            

The habitat is able to withstand severe disturbances as the environment they live in is prone to a high frequency of these events. Moreover, in some cases they are naturally adapted to high nutrient levels as they are situated on estuarine environments. In general, the subhabitat of Cystoseira barbata f. repens is more vulnerable than other subhabitats to environmental pressures. Dominance by species of UlvaCladophora and Gayralia usually indicate high quantities of nutrients. The presence of Syngnathidae (HippocampusSyngnathus) usually indicates good environmental quality. 

 

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

Threat status

Synthesis of Red List assessment

In spite of the widespread nature and importance of this habitat, very little is known about it. The habitat is known to have suffered substantial habitat loss and also degradation in quality over the last 50 years and this is expected to continue. The scale of habitat loss has been estimated as over 50%. Declines in quality cannot be quantified. This habitat has therefore been assessed as Endangered at the EU 28 and at the EU 28+ .
EU
Red List Category Red List Criteria
Endangered A1
Europe
Red List Category Red List Criteria
Endangered A1

Confidence in the assessment

medium
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Pollution
    • Pollution to surface waters (limnic, terrestrial, marine & brackish)
    • Nutrient enrichment (N, P, organic matter)
  • Invasive, other problematic species and genes
    • Invasive non-native species
  • Natural System modifications
    • Canalisation & water deviation
    • Flooding modifications
    • Modification of hydrographic functioning, general
    • Altered water quality due anthropogenic changes in salinity
  • Natural biotic and abiotic processes (without catastrophes)
    • Species composition change (succession)
    • Accumulation of organic material
    • Eutrophication (natural)
  • Climate change
    • Temperature changes (e.g. rise of temperature & extremes)
    • Droughts and less precipitations
    • pH-changes

Habitat restoration potential

Recovery through intervention to improve water quality and transplantation of Cystoseira specimens has been suggested as a tool to be explored in order to restore extinct populations.

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

The protection of coastal wetlands has become a priority objective in resource conservation policies of the Mediterranean region. The lack of an adequate management of these areas has been recognized in several forums as the main cause leading to an ecological degradation and as a consequence, to the different associated habitats. Different management strategies have been applied in different countries, however there is limited information on their effectiveness. Given the current and forecast impacts, there is also a strong need to design management policies to mitigate climate change impacts. Recovery through intervention to improve water quality would also be beneficial.

List of conservation and management needs

  • Measures related to wetland, freshwater and coastal habitats
    • Restoring/Improving water quality
    • Restoring/Improving the hydrological regime
    • Restoring coastal areas
  • Measures related to spatial planning
    • Establish protected areas/sites

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 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 2,180,533 140 1805 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+ 207 >1805 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 Acetabularia calyculus
Algae Alsidium corallinum
Algae Caulerpa prolifera
Algae Caulerpa taxifolia
Algae Chaetomorpha crassa
Algae Chaetomorpha linum
Algae Cladophora echinus
Algae Cladophora vagabunda
Algae Cystoseira barbata
Algae Dictyota mediterranea
Algae Gracilaria dura
Algae Gracilaria gracilis
Algae Lithothamnion corallioides
Algae Osmundaria volubilis
Algae Penicillus capitatus
Algae Radicilingua thysanorhizans
Algae Sargassum muticum
Algae Ulva curvata
Algae Ulva rigida
Algae Undaria pinnatifida
Algae Valonia aegagropila
Fishes Atherina boyeri
Fishes Atherina presbyter
Fishes Chelon labrosus
Fishes Gobius niger
Fishes Hippocampus guttulatus
Fishes Hippocampus hippocampus
Fishes Liza ramada
Fishes Mugil cephalus
Fishes Syngnathus abaster
Flowering Plants Posidonia oceanica
Invertebrates Carcinus aestuarii
Invertebrates Crangon crangon
Invertebrates Ilia nucleus
Invertebrates Palaemon adspersus
Invertebrates Palaemon xiphias
Invertebrates Zoobotryon verticillatum
Species scientific name English common name Species group
Acetabularia calyculus Algae
Alsidium corallinum Algae
Caulerpa prolifera Algae
Caulerpa taxifolia Algae
Chaetomorpha crassa Algae
Chaetomorpha linum Algae
Cladophora echinus Algae
Cladophora vagabunda Algae
Cystoseira barbata Algae
Dictyota mediterranea Algae
Gracilaria dura Algae
Gracilaria gracilis Algae
Lithothamnion corallioides Algae
Osmundaria volubilis Algae
Penicillus capitatus Algae
Radicilingua thysanorhizans Algae
Sargassum muticum Algae
Ulva curvata Algae
Ulva rigida Algae
Undaria pinnatifida Algae
Valonia aegagropila Algae
Atherina boyeri Big-scale sand smelt Fishes
Atherina presbyter Atherine Fishes
Chelon labrosus Lesser grey mullet Fishes
Gobius niger Black goby Fishes
Hippocampus guttulatus Long-snouted seahorse Fishes
Hippocampus hippocampus Sea horse Fishes
Liza ramada Haarder Fishes
Mugil cephalus Black true mullet Fishes
Syngnathus abaster Black-striped pipefish Fishes
Posidonia oceanica Flowering Plants
Carcinus aestuarii Invertebrates
Crangon crangon Invertebrates
Ilia nucleus Invertebrates
Palaemon adspersus Invertebrates
Palaemon xiphias Invertebrates
Zoobotryon verticillatum Invertebrates

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
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