Red List habitat classification > RL - Marine habitats > RLBLS - Black Sea > BLSA3.34 Fucales and other algae on Pontic sheltered upper infralittoral rock, well illuminated

Fucales and other algae on Pontic sheltered upper infralittoral rock, well illuminated

Quick facts

Red List habitat type code BLSA3.34
Threat status
Europe Vulnerable
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 is present in shallow sheltered waters, such as semi-enclosed bays on rocky substrates. Reported at depths of 1-14 m although also known to occur in deeper waters in the pre-eutrophication period in the early 1980s. Cystoseira belt, in this habitat is dominated by C. barbata, provides an ideal substrate and habitat for numerous photophilic and sciaphilic algal species, especially Rhodophyta.

C. barbata is typically the dominant canopy-forming species in this sheltered environment, with C. crinita and C. bosphorica being more common in exposed situations. Other species present include the algae Ulva rigida, Polysiphonia subulifera, Cladophora spp., Gelidium spinosum and occasionally present C. crinita and Ceramium virgatum. The bivalves Mytilus galloprovincialis and Mytilaster lineatus are also very abundant in this habitat and often colonise all the substrate available between the C. barbata plants, or attach to the main axis of the plants. An understory of Dilophus fasciola and Cladostephus spongiosus is typical of oligotrophic waters (Cystoseiretum dilophoso-cladostephosum). A third layer is formed by Padina pavonia and Corallina elongataGelidium latifolium with G. spinosum (= G. crinale) also present. A fourth layer of crust-forming Hildenbrandia rubra is also typical. Epiphytic algae include Laurencia coronopusPolysiphonia subuliferaCeramium rubrum, Corynophlaea umbellata, Stilophora rhizodes, and Jania rubens.

Suitable indicators of quality include: community and population structure, diversity, biomass and abundance, epiphytic species richness, water quality and substrate. Appropriate thresholds include:

1.       Cystoseira spp. canopies occur in all areas with suitable habitat. Habitat fragmentation is reduced.

2.       Cystoseira spp. cover inside the canopy is ≥50%

3.       Height of Cystoseira spp. thalli during the cold season is ≥100 cm for at least 50% of the population

4.       Epiphyte-free wet biomass of Cystoseira spp. is ≥3,000 g/m2

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

Threat status

Synthesis of Red List assessment

In the EU 28 the habitat has been assessed as Endangered using Criteria C/D1. There is evidence of intermediate or moderate levels of decline affecting >80% of the habitat with substantial changes in vertical structure and the reduced cover and frequency of many characteristic species. Although there are quantitative data from sites in Romania and Bulgaria this assessment WAS mostly based on expert opinion. There is evidence of reduction at a site level and these results were extrapolated and are believed to represent the whole region.
In the EU 28+ the habitat has been assessed as Vulnerable using Criteria C/D1. There is evidence of intermediate or moderate levels of decline affecting >50% of the habitat. Intermediate or moderate decline is based on substantial changes in vertical structure and the reduced cover and frequency of many characteristic species. This is supported by quantitative data from sites in Romania, Bulgaria and Crimea. No data is available for Turkey or Georgia. Qualitative data for these countries is also lacking. The assessment has mostly been based on expert opinion.
EU
Red List Category Red List Criteria
Endangered C/D1
Europe
Red List Category Red List Criteria
Vulnerable C/D1

Confidence in the assessment

medium
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Urbanisation, residential and commercial development
    • Other urbanisation, industrial and similar activities
  • Pollution
    • Nutrient enrichment (N, P, organic matter)
  • Natural System modifications
    • Siltation rate changes, dumping, depositing of dredged deposits
  • Geological events, natural catastrophes
    • Storm, cyclone
  • Climate change
    • Temperature changes (e.g. rise of temperature & extremes)

Habitat restoration potential

Recent reduction in eutrophication levels in the Black Sea have shown that the habitat has the ability to stabilise. There is also evidence that the habitat can begin to recover where eutrophication levels remain low. Where artificial substrates have been installed the habitat has shown the ability to colonise these, albeit in a degraded form. The time scales taken for recovery will depend on abiotic conditions and the trend that these show.

Trends in extent

Average current trend in quantity

Stable Stable
EU28 EU28+

Trends in quality

Average current trend in quality

Stable Stable
EU28 EU28+

Conservation and management needs

Current approaches to protect this habitat include designating protected areas, reduction of nutrient inputs, the protection of species.
This habitat exists within protected areas in Romania, Russia and Bulgaria. In Romania and Bulgaria it is listed as a national sub-type of Annex I of the Habitats Directive.
Additional actions should seek to expand all the current approaches to all states bordering the Black Sea. This should include efforts to improve marine water quality and reduce eutrophication.

List of conservation and management needs

  • Measures related to marine habitats
    • Other marine-related measures
    • 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)
Black Sea Present Unknown Decreasing Decreasing
Sea of Marmara

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 9060 17 Unknown Area estimates are available at some locations (e.g. sites in Crimean and Romania) However, these are only a small proportion of the total area and cannot be used as an estimate.
EU28+ 233 Unknown Area estimates are available at some locations (e.g. sites in Crimean and Romania) However, these are only a small proportion of the total area and cannot be used as an estimate.
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 Ceramium rubrum
Algae Cladostephus spongiosus
Algae Corallina elongata
Algae Corynophlaea umbellata
Algae Gelidium spinosum
Algae Hildenbrandia rubra
Algae Jania rubens
Algae Polysiphonia subulifera
Algae Ulva rigida
Invertebrates Mytilaster lineatus
Invertebrates Mytilus galloprovincialis
Species scientific name English common name Species group
Ceramium rubrum Algae
Cladostephus spongiosus Algae
Corallina elongata Algae
Corynophlaea umbellata Algae
Gelidium spinosum Algae
Hildenbrandia rubra Algae
Jania rubens Algae
Polysiphonia subulifera Algae
Ulva rigida Algae
Mytilaster lineatus Invertebrates
Mytilus galloprovincialis 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