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.
Characteristic species
For full habitat description, please download the habitat factsheet.
Threat status
Synthesis of Red List assessment
This habitat has a large natural range in the North East Atlantic. A combination of survey data and modelling indicates that it does not have a restricted geographical distribution nor occur in only a few locations in the North East Atlantic and therefore qualifies as Least Concern under criterion B. Most sedimentary benthic systems on the continental shelf of Europe have been modified by fishing activities, particularly bottom trawls and dredging, in the last 100 years and this habitat remains under fishing pressure and subject to aggregate extraction. Data for 2013/2014 has revealed that over 70% of this habitat in the North Sea and Celtic Sea was subject to fishing pressure by bottom otter, beam and mid-water trawls. Coarse sediment communities have greater resilience and faster recovery rates that those in fine sediments but given that this is based on a single year of data and that this type of pressure has been taking place for decades it is likely to be an underestimate of the total area of this habitat which has been subject to such pressure.
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.
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
medium
Red List of habitat categories and criteria descriptions
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
Studies on the recovery of coarse sediment habitats following aggregate dredging indicate that the tidal stress regime is an important consideration in recovery times. In highly energetic conditions recovery may take less than 2 years but under other conditions recovery may take more than 20 years. If the sediment composition is altered the species composition may be different to that which existed before the habtiat was damaged. Recovery from damage associated with demersal trawling will also depend on the frequency of disturbance.
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
Beneficial management measures include the control of demersal fishing activity and the regulation of activities which damage or disturb seabed communities such as aggregate dredging and offshore construction work. Establishing undisturbed areas may also be beneficial by helping to facilitate the recolonisation of previously degraded areas.
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
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) |
|---|---|---|---|---|
| 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. |
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
The full list of characteristic species and genus are available above from the Summary. The species available in the EUNIS database are shown here.
Invertebrates
Amythasides macroglossus
Invertebrates
Glycera lapidum
Invertebrates
Hesionura elongata
Invertebrates
Modiolus modiolus
Invertebrates
Protodorvillea kefersteini
Invertebrates
Amythasides macroglossus
Invertebrates
Glycera lapidum
Invertebrates
Hesionura elongata
Invertebrates
Modiolus modiolus
Invertebrates
Protodorvillea kefersteini
| Species scientific name | English common name | Species group |
|---|---|---|
| Amythasides macroglossus | Invertebrates | |
| Glycera lapidum | Invertebrates | |
| Hesionura elongata | Invertebrates | |
| Modiolus modiolus | Invertebrates | |
| Protodorvillea kefersteini | Invertebrates |
Vegetation types
Relation to vegetation types (syntaxa)
Not availableOther classifications
Not available
