Seagrass meadows in Pontic lower infralittoral sands
Quick facts
Red List habitat type | code BLSA5.5w |
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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
Seagrass beds are found on sandy and sandy-muddy bottoms in sheltered habitats with sufficient lighting. Maximum development is in the summer. The habitat occurs all around the Black Sea as small and fragmented meadows. Its distribution is well documented in Russia, Ukraine, Romania and Bulgaria, while for Turkey it is mostly unknown. Off the coast of Georgia sparse eelgrass meadows are known to occur at Cape Souk-Sou (after Cystoseira communities at a depth of 6-10 m), in the Gulf of Skurge at a depth of 4-6 m. This habitat contains communities in both the upper and lower infralittoral sands with different dominant eelgrass species:
The habitat occurs in the deeper infralittoral zone, most typically where the sediment is silty sand and in the 10 m depth range. The meadows are found in sea water with salinity varying between 11 and 19 psu. Six species of seagrass may be present in this habitat but Zostera marina is generally dominant. There are also algae living on the eelgrass blades, mostly red algae. Species diversity develops two peaks, one in spring and the other in autumn. Seasonal dynamics of the biomass and density are less pronounced due to the depth. The communities of Z. marina display greatest diversity in the Kerch Strait with its special hydrological and hydrochemical conditions.
Indicators of quality:
Leaf length, biomass, shoot density have all been identified has indicators of quality. However, thresholds have not been set and these can and will vary between countries.
Threat status
Synthesis of Red List assessment
EU | |
Red List Category | Red List Criteria |
Endangered | B1b, B2b |
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
- Human intrusions and disturbances
- Other human intrusions and disturbances
- Trampling, overuse
- Pollution
- Nutrient enrichment (N, P, organic matter)
Habitat restoration potential
Trends in extent |
|
Average current trend in quantity |
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Decreasing ![]() |
Decreasing ![]() |
EU28 | EU28+ |
Trends in quality |
|
Average current trend in quality |
|
Stable ![]() |
Decreasing ![]() |
EU28 | EU28+ |
Conservation and management needs
List of conservation and management needs
- Measures related to marine habitats
- Other marine-related measures
- Measures related to spatial planning
- Establish protected areas/sites
- Legal protection of habitats and species
- Measures related to urban areas, industry, energy and transport
- Other measures
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) |
---|---|---|---|---|
Black Sea | Present | Unknown | Unknown | Unknown |
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 | 9,155 | 13 | 13,00 | EOO and AOO have been calculated on the available data. |
EU28+ | 146 | 14,600 | EOO and AOO have been calculated on the available data. |
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 |
---|---|---|
Cystoseira barbata | Algae | |
Gracilaria gracilis | Algae | |
Zostera marina | Flowering Plants |