Atlantic upper circalittoral coarse sediment
Quick facts
| Red List habitat type | code NEAA5.14 |
|---|---|
| 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 comprises tide-swept circalittoral coarse sand, gravel, pebbles, shingle and cobbles which are often unstable due to tidal currents and/or wave action. It is typically found in depths of over 15-20m and is present in tidal channels of marine inlets and along exposed coasts and offshore. The associated biotopes are characterised by robust infaunal polychaetes, mobile crustacea and bivalves. Certain species of sea cucumber (e.g. Neopentadactyla) may also be prevalent, along with the lancelet Branchiostoma lanceolatum. Where the sediment is mobile or unstable, the epibenthic fauna may limited to the keel worm Pomatoceros triqueter with barnacles and bryozoan crusts as these species have some resistance to abrasion and can rapidly colonise areas after successful spatfalls. In locations with weak or no current the fauna is dominated by polychaetes. Scallops may occur on the sediment surface in areas of shell gravel that are subject to some sand scour.
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
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 more than 60% 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 it is clear that in some locations there has also 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 dredging
- Pollution
- Marine water pollution
- Toxic chemical discharge from material dumped at sea
- Synthetic compound contamination
- Natural System modifications
- Extraction of sea-floor and subsoil minerals (e.g. sand, gravel, rock, oil, gas)
- Alteration of sea-floor/ Water body morphology
- Climate change
- Changes in abiotic conditions
- Water flow changes (limnic, tidal and oceanic)
- Wave exposure changes
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 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
- 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 | 4,881,445 | 3,701 | >84,576 | 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. No precise figure |
| EU28+ | >3,701 | >84,576 | 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).
