Atlantic upper circalittoral fine sand
Quick facts
Red List habitat type | code NEAA5.25 |
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Threat status | |
Europe | Endangered |
EU | Endangered |
Relation to |
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Source | European Red List habitat factsheet |
European Red List of habitats reports | |
European Red List of habitats (Excel table) |
Summary
This habitat consists of clean fine sands with less than 5% silt/clay in deeper water in tide-swept channels of marine inlets or on the open coast, extending offshore in depths of over 15-20 m. Off the coast of Portugal it has been reported in depths of 20-37m in areas of moderately strong current. It is characterised by a wide range of echinoderms as well as polychaetes and bivalves. Frequently occurring species include the brittlestar Amphiura filiformis, Ophiura albida and O.ophiura, the anemone Cerianthus lloydii, and polychaete worms such as Lanice conchilega.
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. Examples of indicators of "naturalness" that are potential indicators for quality identified for offshore sands are; typical populations of bivalves and epifaunal brittlestars; maintained presence of substratum; lack of smothering; typically diverse communities with no increase in hardy or opportunistic species; and maintenance of sediment characteristics with typical levels of diversity.
Threat status
Synthesis of Red List assessment
Most sedimentary benthic systems on the continental shelf of Europe are believed to have been modified by fishing activities in the last 100 years, particularly by mobile demersal gears, and this habitat remains under fishing pressure. Data from a single year, 2013/2014, has revealed that than 40% of circalittoral fine sands and muddy sand were subject to trawling fishing pressure in the North Sea, with over 10% of this being interpreted a high or moderate pressure. When combining data for the North Sea and Celtic Sea more than 80% of this habitat type is considered to have been subject to such fishing pressure. 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. Disturbance of the substratum due to intensive fishing activities using bottom trawls or dredges can damage or modify infaunal communities, with burrowing echinoderms and bivalves being particularly vulnerable and therefore affect habitat quality.
Expert opinion is that there has been a very substantial reduction in quality of this habitat, most likely an intermediate decline affecting more than 80% 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 Endangered 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 |
Endangered | C/D1 |
Europe | |
Red List Category | Red List Criteria |
Endangered | 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
- Pollution
- Marine water pollution
- Toxic chemical discharge from material dumped at sea
- Non-synthetic compound contamination
- Synthetic compound contamination
- Natural System modifications
- Human induced changes in hydraulic conditions
- Removal of sediments (mud...)
- Estuarine and coastal dredging
- Extraction of sea-floor and subsoil minerals (e.g. sand, gravel, rock, oil, gas)
- Change of sea-floor substrate
- Dykes, embankments, artificial beaches, general
- Sea defense or coast protection works, tidal barrages
- Dykes and flooding defense in inland water systems
Habitat restoration potential
Thyasirids, small burrowing bivalves which live in fine sediments, are thought to be fairly slow growing and recovery of a damaged population is likely to take up to 5 years and depends on direct recruitment from the same population due to the low dispersal potential of these species. Where they occur in isolated poulations they are therefore unlikely to recover if lost. In comparison, the high fecundity and larval dispersal potential of many of the polychaetes associated with this habitat is likely to result in a population recovering quite quickly - in less than a year for O. fusiformis and in approximately 5-6 years for A. filiformis due to the later age at which it reaches sexual maturity
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
- 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
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) |
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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 | 4,005,871 | 1,236 | >10,997 | 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. |
EU28+ | >1,236 | >10,997 | 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 |
---|---|---|
Abra prismatica | Invertebrates | |
Amphiura filiformis | Invertebrates | |
Aonides paucibranchiata | Invertebrates | |
Asterias rubens | Invertebrates | |
Bathyporeia elegans | Invertebrates | |
Chaetozone setosa | Invertebrates | |
Echinocardium cordatum | Invertebrates | |
Echinocyamus pusillus | Invertebrates | |
Lanice conchilega | Invertebrates | |
Mactra stultorum | Invertebrates | |
Magelona johnstoni | Invertebrates | |
Mediomastus fragilis | Invertebrates | |
Nephtys longosetosa | Invertebrates | |
Ophelia borealis | Invertebrates | |
Ophiura albida | Invertebrates | |
Owenia fusiformis | Invertebrates | |
Pagurus bernhardus | Invertebrates | |
Scoloplos armiger | Invertebrates | |
Spiophanes bombyx | Invertebrates |