Mediterranean infralittoral oyster beds
Quick facts
Red List habitat type | code MEDA5.6w |
---|---|
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
Infralittoral oyster beds on rocky and soft bottoms comprised mainly by the European flat oyster Ostrea edulis with densities of 5 or more per m2. The oysters cement themself to the substratum and can form a dense cover. They may be found as individuals or clusters attached to rock surfaces, on other shelled animals like the endemic noble shell (Pinna nobilis) or on coarse sandy bottoms. The diet of oysters consists of phytoplankton and detritus filtered from the surrounding water. More frequently they can be found close to river mouth areas or estuaries and sheltered bays. There are three distinct habitat components; the interstices within the oyster matrix; the biodeposits beneath the bed; and the substratum afforded by the oyster shells themselves. A diverse range of epibiota and infauna often exists in these parts of the habitat.
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. Presence and abundance of the oyster will be a key indicator of this habitat.
Threat status
Synthesis of Red List assessment
EU | |
Red List Category | Red List Criteria |
Endangered | A3 |
Europe | |
Red List Category | Red List Criteria |
Endangered | A3 |
Confidence in the assessment
Pressures and threats
- Biological resource use other than agriculture & forestry
- Marine and Freshwater Aquaculture
- Fishing and harvesting aquatic resources
- Pollution
- Pollution to surface waters (limnic, terrestrial, marine & brackish)
- Marine water pollution
- Invasive, other problematic species and genes
- Invasive non-native species
- Climate change
- Changes in abiotic conditions
- Changes in biotic conditions
Habitat restoration potential
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
List of conservation and management needs
- Measures related to wetland, freshwater and coastal habitats
- Restoring/Improving water quality
- Measures related to marine habitats
- Restoring marine habitats
- Measures related to spatial planning
- Establish protected areas/sites
- Legal protection of habitats and species
- Measures related to hunting, taking and fishing and species management
- Regulation/Management of fishery in marine and brackish systems
- Measures related to urban areas, industry, energy and transport
- Urban and industrial waste management
- Measures related to special resouce use
- Regulating/Managing exploitation of natural resources on sea
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) |
---|---|---|---|---|
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 | 1,411,607 | 212 | Unknown | 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+ | 212 | Unknown | 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. |
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 |
---|---|---|
Crassostrea gigas | Invertebrates | |
Ostrea edulis | Flat oyster | Invertebrates |
Pinna nobilis | Invertebrates | |
Stramonita haemastoma | Invertebrates |
Legal status
Relation to other habitat types mentioned in legal instruments
Legal text | Annex | Name in legal text | Code in legal text |
Habitat type relationship |
More information |
---|---|---|---|---|---|
Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora - consolidated version 01/01/2007 | Annex I: natural habitat types of community interest whose conservation requires the designation of special areas of conservation | Reefs | 1170 | Narrower | http://ec.europa.eu/environm...rective/index_en.htm |