Atlantic lower circalittoral coarse sediment
.jpg "European Red List of Habitats 2016")
.jpg "European Red List of Habitats 2016")
Quick facts
| Red List habitat type | code NEAA5.15 |
|---|---|
| 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
This habitat is present in offshore circalittoral coarse sands and gravel or shell gravel, typically in depths of over 20m. There are relatively little quantitative data available, but it is thought to cover large areas of the offshore continental shelf. It is generally characterised by robust infaunal polychaete and bivalve species and is relatively diverse. The characteristic species depend on the fraction of coarse and finder sediments. In some areas settlement of Modiolus modiolus larvae may occur and consequently these habitats may occasionally have large numbers of juvenile M. modiolus. In areas where the mussels reach maturity their byssus threads bind the sediment together, increasing stability and allowing an increased deposition of silt.
Indicators of quality:
Both biotic and abiotic indicators have been used to describe marine habitat quality. These include: the presence of characteristic species as well as those which are sensitive to the pressures the habitat may face; water quality parameters; levels of exposure to particular pressure, and more integrated indices which describe habitat structure and function, such as trophic index, or successional stages of development in habitats that have a natural cycle of change over time.
There are no commonly agreed indicators of quality for this habitat, although particular parameters may have been set in certain situations e.g. protected features within Natura 2000 sites, where reference values have been determined and applied on a location-specific basis.
Threat status
Synthesis of Red List assessment
Expert opinion is that there has been a substantial reduction in quality of this habitat, most likely an intermediate decline affecting more than 50% of its extent although in some locations there may have been a severe decline. The severity will depend on factors such as the intensity and frequency of disturbance. This habitat has therefore been assessed as Vulnerable for both the EU 28 and EU 28+ because of both past and likely continuing declines in quality.
| EU | |
| Red List Category | Red List Criteria |
| Vulnerable | C/D1 |
| Europe | |
| Red List Category | Red List Criteria |
| Vulnerable | C/D1 |
Confidence in the assessment
Pressures and threats
- Biological resource use other than agriculture & forestry
- Fishing and harvesting aquatic resources
- Professional active fishing
- Benthic or demersal trawling
- Benthic dredging
- Natural System modifications
- Extraction of sea-floor and subsoil minerals (e.g. sand, gravel, rock, oil, gas)
- Alteration of sea-floor/ Water body morphology
Habitat restoration potential
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
List of conservation and management needs
- Measures related to marine habitats
- Other marine-related measures
- Measures related to spatial planning
- Establish protected areas/sites
- Measures related to hunting, taking and fishing and species management
- Regulation/Management of fishery in marine and brackish systems
- 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) |
|---|---|---|---|---|
| Bay of Biscay and the Iberian Coast | Present | Unknown | Decreasing | Unknown |
| Celtic Seas | ||||
| Greater North Sea | ||||
| Macaronesia | ||||
| Kattegat |
Extent of Occurrence, Area of Occupancy and habitat area
| Extent of Occurrence (EOO) (Km2) | Area of Occupancy (AOO) | Current estimated Total Area | Comment | |
|---|---|---|---|---|
| EU28 | 4,888,700 | 3,382 | >87,676 | 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+ | >3,382 | >87,676 | The area estimate for this habitat has been derived from a synthesis of EUNIS seabed habitat geospatial information for the European Seas but is recognised as being an underestimate. |
EOO = the area (km2) of the envelope around all occurrences of a habitat (calculated by a minimum convex polygon).
