Seagrass and rhizomatous algal meadows in Pontic freshwater-influenced sheltered infralittoral muddy sands and sandy muds
Quick facts
Red List habitat type | code BLSA5.53 |
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Threat status | |
Europe | Near Threatened |
EU | Least Concern |
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 occurs in sheltered shallow (0.5-2 m) coastal waters (embayments, inlets, bights, harbours, estuaries), more or less influenced by freshwater (salinity 0.5-10 psu), where sedimentary stability leads to mudding of the sand. Mixed or monospecific meadows are formed by Zostera noltei, Ruppia maritima, R. cirrhosa, Chara spp., Stuckenia pectinata (formerly known as Potamogeton pectinatus), Najas minor and Ranunculus baudotii. Algae commonly found include species of Cladophora and Ulva which are tolerant of very low salinities.
Indicators of quality:
Both biotic and abiotic indicators have been used to describe marine habitat quality. These include the presence of particular species, water quality parameters, levels of exposure to a particular exposure as well as more integrated indices which describe habitat function and structure, such as trophic index, or successful stages of development in habitats that have a natural cycle of change over time. There are no known commonly agreed indicators of quality for this habitat, although particular parameters may be set in certain situations, e.g. protected features with Natura 2000 sites, where reference values may have been determined and applied on a location-specific basis. Some potential indicators of quality for this specific habitat are thepresence of species (i.e. Zanichellia and Ruppia); species density; species composition; the ratio of higher plants to seagrasses; and biomass. There is insufficient information to set indicator thresholds required for monitoring purposes.
Threat status
Synthesis of Red List assessment
In the EU 28+ the habitat type is assessed as Near Threatened under Criterion A1 as there has been a decline in extent of 25-30% in the last 50 years. This based on a combination of quantitative and qualitative data and expert opinion. Data is from sites in Crimea and Ukraine only and has been extrapolated for the rest of the Black Sea.
EU | |
Red List Category | Red List Criteria |
Least Concern | - |
Europe | |
Red List Category | Red List Criteria |
Near Threatened | A1 |
Confidence in the assessment
Pressures and threats
- Pollution
- Pollution to surface waters (limnic, terrestrial, marine & brackish)
- Nutrient enrichment (N, P, organic matter)
- Natural System modifications
- Human induced changes in hydraulic conditions
- Removal of sediments (mud...)
- Extraction of sea-floor and subsoil minerals (e.g. sand, gravel, rock, oil, gas)
- Modification of hydrographic functioning, general
- Siltation rate changes, dumping, depositing of dredged deposits
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 |
|
Decreasing ![]() |
Decreasing ![]() |
EU28 | EU28+ |
Conservation and management needs
In EU states water quality and management are managed by the Water Framework Directive (WFD). Future management should include the designation of additional protected areas in non EU member states and improvement of water quality management and extraction regulations outside EU member states
List of conservation and management needs
- Measures related to wetland, freshwater and coastal habitats
- Restoring/Improving water quality
- Restoring/Improving the hydrological regime
- Managing water abstraction
- 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) |
---|---|---|---|---|
Black Sea | Present | Unknown | Decreasing | Decreasing |
Extent of Occurrence, Area of Occupancy and habitat area
Extent of Occurrence (EOO) (Km2) | Area of Occupancy (AOO) | Current estimated Total Area | Comment | |
---|---|---|---|---|
EU28 | 21,555 | 18 | Unknown | Current total area of the habitat is unknown. Localities are known but not studied in detail. Total area estimates cannot be calculated. |
EU28+ | 65 | Unknown | Current total area of the habitat is unknown. Localities are known but not studied in detail. Total area estimates cannot be calculated. |
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).