Communities of Mediterranean lower circalittoral sand
Quick facts
| Red List habitat type | code MEDA5.27 |
|---|---|
| Threat status | |
| Europe | Vulnerable |
| EU | Vulnerable |
| Relation to |
|
| Source | European Red List habitat factsheet |
| European Red List of habitats reports | |
| European Red List of habitats (Excel table) |
Summary
A habitat in the deepest part of the circalittoral zone extending down to 200 m of depth. The sediment comprises fine sands or non-cohesive muddy sands. Whilst the process of sedimentation is constant, the movement of water masses is reduced compared to shallower areas making it a more stable environment. Animal communities dominate characterised by a diverse range of polychaetes, cnidarians, amphipods, bivalves and echinoderms. The lower circalittoral zone marks the survival boundary of autotrophic pluricellular algae.
Indicators of quality:
There are no commonly agreed indicators of quality for this habitat, thus both standard biotic and abiotic indicators have been used to describe marine habitat quality. As this habitat can be impacted by fisheries activities, particularly trawling, the presence or absence of characteristic commercially exploited species are a potential quality indicator.
Characteristic species
For full habitat description, please download the habitat factsheet.
Threat status
Synthesis of Red List assessment
This habitat is widespread and common in the Eastern and Western Mediterranean. The precise extent is unknown but estimated as EOO >50,000km2 and AOO >50 which exceeds the thresholds for a threatened category on the basis of restricted geographic distribution. It is affected by demersal fishing activities, as well as natural changes in sedimentation rates but it difficult to determine whether there have been any trends in quantity as a result.
The continental shelf area in the EU Mediterranean countries is almost all subject to a high intensity of trawled gear fishing increasing on an east to west gradient with the highest intensity and extent in the Adriatic Sea. All available data are indicating that a majority of the circalittoral zone (more than 80%) has suffered a decline in abiotic and biotic quality predominantly due to the effects of fishing and the aquaculture industry. This specific habitat has been affected by the use of demersal fishing gears with reports of decline in quality from many areas. Expert opinion is that this is likely to amount to a substantial reduction represented by an intermediate decline affecting more than 50% of the extent in both the EU 28 and EU 28+. This habitat has therefore been assessed as Vulnerable under criteria C/D1.
The continental shelf area in the EU Mediterranean countries is almost all subject to a high intensity of trawled gear fishing increasing on an east to west gradient with the highest intensity and extent in the Adriatic Sea. All available data are indicating that a majority of the circalittoral zone (more than 80%) has suffered a decline in abiotic and biotic quality predominantly due to the effects of fishing and the aquaculture industry. This specific habitat has been affected by the use of demersal fishing gears with reports of decline in quality from many areas. Expert opinion is that this is likely to amount to a substantial reduction represented by an intermediate decline affecting more than 50% of the extent in both the EU 28 and EU 28+. This habitat has therefore been assessed as Vulnerable under criteria C/D1.
| EU | |
| Red List Category | Red List Criteria |
| Vulnerable | C/D1 |
| Europe | |
| Red List Category | Red List Criteria |
| Vulnerable | C/D1 |
Confidence in the assessment
low
Red List of habitat categories and criteria descriptions
Pressures and threats
- Biological resource use other than agriculture & forestry
- Fishing and harvesting aquatic resources
- Benthic or demersal trawling
- Benthic dredging
- Pollution
- Nutrient enrichment (N, P, organic matter)
- Marine water pollution
- Soil pollution and solid waste (excluding discharges)
Habitat restoration potential
Unknown. Large bodied, slow growing fauna such as bivalves which are associated with this habitat are sensitive to fishing disturbances and their populations may be slow to recover. Areas that are heavily fished may never fully recover because the seabed is re-disturbed before recovery has taken place. The timescales for recovery will depend on the individual area and the community present,
Trends in extent |
|
Average current trend in quantity |
|
Unknown  |
Unknown |
| EU28 | EU28+ |
Trends in quality |
|
Average current trend in quality |
|
Decreasing  |
Decreasing |
| EU28 | EU28+ |
Conservation and management needs
The regulation of fishing activities is key to conservation of this habitat. This may include gear modifications, spatial and season restrictions as well as bycatch limits. Controls on land based sources of pollution will also benefit this habitat.
List of conservation and management needs
- Measures related to wetland, freshwater and coastal habitats
- Restoring/Improving water quality
- 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
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) |
|---|---|---|---|---|
| Adriatic Sea | Present | Unknown | Stable | 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 | >50,000 | >50 | Unknown | This habitat is present in all the Mediterranean sub-basins. |
| EU28+ | >50 | Unknown | This habitat is present in all the Mediterranean sub-basins. |
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).
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).
Characteristic species
Not available
Vegetation types
Relation to vegetation types (syntaxa)
Not availableOther classifications
Not available
