Fucales and other algae on Pontic sheltered upper infralittoral rock, well illuminated
Quick facts
Red List habitat type | code BLSA3.34 |
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Threat status | |
Europe | Vulnerable |
EU | Endangered |
Relation to |
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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 elongata. Gelidium latifolium with G. spinosum (= G. crinale) also present. A fourth layer of crust-forming Hildenbrandia rubra is also typical. Epiphytic algae include Laurencia coronopus, Polysiphonia subulifera, Ceramium 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
Threat status
Synthesis of Red List assessment
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
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
Trends in extent |
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Average current trend in quantity |
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Stable ![]() |
Stable ![]() |
EU28 | EU28+ |
Trends in quality |
|
Average current trend in quality |
|
Stable ![]() |
Stable ![]() |
EU28 | EU28+ |
Conservation and management needs
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
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) |
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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. |
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).
Characteristic species
Species scientific name | English common name | Species group |
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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 |