Red List habitat classification > RL - Marine habitats > RLNEA - Atlantic > NEAA5.35 Atlantic upper circalittoral sandy mud

Atlantic upper circalittoral sandy mud

Quick facts

Red List habitat type code NEAA5.35
Threat status
Europe Endangered
EU Endangered
Relation to
Source European Red List habitat factsheet
European Red List of habitats reports
European Red List of habitats (Excel table)

Summary

The substrate of this benthic habitat is predominantly cohesive sandy mud, typically with over 20% silt/clay content. It usually occurs in water depths of over 10 m, in areas with weak or very weak tidal streams. It is also present in deeper areas of bays and marine inlets or offshore from less wave exposed coasts. The epifauna may be sparse and scattered  characterised by Sea pens such as Virgularia mirabilis and brittlestars such as Amphiura spp. (e.g. Amphiura filiformis). Mounds, burrows, and tubes indicate the presence of infauna. 

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.

Characteristic species
For full habitat description, please download the habitat factsheet.

Threat status

Synthesis of Red List assessment

Most sedimentary benthic systems on the continental shelf of Europe have been modified by fishing activities in the last 100 years, particularly by mobile demersal gears, and this habitat remains under such fishing pressure which can damage or modify infaunal and epifaunal communities. Data for a single year (2013/2014) has revealed that over 60% of this habitat in the North Sea and Celtic Sea was subject to fishing pressure by bottom otter, beam and mid-water trawls. In the German part of the Greater North Sea, more than 80% of the extent of this habitat is believed to have suffered an intermediate decline in quality over the last 50 years.
The extent of the likely impact of bottom fishing gears on this habitat throughout the North East Atlantic region is also apparent from other analyses which have combined VMS data with sensitivity maps of benthic habitats and disturbance caused by surface abrasion for the continental shelf area of the North East Atlantic. In the case of benthic habitats on sandy mud substrate for just 2013 this has shown that more than 80% of its occurrence across the shelf area has been subject to abrasion disturbance. Much the same footprint of activity is likely each year and as this type of fishing pressure has been ongoing for many decades, there has most likely been a cumulative impact on 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

medium
Red List of habitat categories and criteria descriptions

Pressures and threats

  • Urbanisation, residential and commercial development
    • Discharges
    • Disposal of industrial waste
  • Biological resource use other than agriculture & forestry
    • Fishing and harvesting aquatic resources
    • Professional active fishing
    • Demersal seining
  • Natural System modifications
    • Human induced changes in hydraulic conditions
    • Modification of hydrographic functioning, general

Habitat restoration potential

Timescale between incidents of damaging activity, the type of damaging activity and the predominant species, influences recovery. Studies have shown that recovery times following dredging were significantly shorter for short-lived species (<1 – 3 years), free-living and tube-dwelling species and for scavenging or opportunistic species, than for medium-lived species (3 – 10 years), burrow-dwelling species and suspension feeders. Free living species are also likely to recolonise areas more quicky that those that grow attached to the substratum and have an erect or stalked body form such as seapens. Differences in the recoverability of different species groups following fishing may result in changes in community composition and ecosystem functioning over the long term.

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

This habitat can benefit from the regulation of the use of fishing gears that damage or disturb seabed communities. This may be achieved by spatial and temporal controls as well as gear design and deployment using fisheries management measures as well as conservation legislation in marine protected areas. Spatial planning (including zoning) can be used to address potential threats from coastal development and fish farming. The regulation of discharges and run off from agricultural land to the marine environment can be used to avoid eutrophication effects associated with nutrient enrichment.

List of conservation and management needs

  • Measures related to marine habitats
    • Other marine-related measures
  • Measures related to spatial planning
    • Other marine-related measures
    • Establish protected areas/sites
  • Measures related to hunting, taking and fishing and species management
    • Regulation/Management of fishery in marine and brackish systems

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
Kattegat
Greater North Sea
Macaronesia

Extent of Occurrence, Area of Occupancy and habitat area

Extent of Occurrence (EOO) (Km2) Area of Occupancy (AOO) Current estimated Total Area Comment
EU28 3,320,427 337 >1,082 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+ >337 >1,082 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.
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).

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 Abra nitida
Invertebrates Ampelisca tenuicornis
Invertebrates Ampharete finmarchica
Invertebrates Amphiura filiformis
Invertebrates Asterias rubens
Invertebrates Diplocirrus glaucus
Invertebrates Iphinoe serrata
Invertebrates Liocarcinus depurator
Invertebrates Maldane glebifex
Invertebrates Mediomastus fragilis
Invertebrates Mysella bidentata
Invertebrates Ninoe armoricana
Invertebrates Ophiura albida
Invertebrates Owenia fusiformis
Invertebrates Pagurus bernhardus
Invertebrates Pariambus typicus
Invertebrates Pholoe inornata
Invertebrates Scoloplos armiger
Invertebrates Terebellides stroemii
Invertebrates Thyasira flexuosa
Invertebrates Virgularia mirabilis
Species scientific name English common name Species group
Abra nitida Invertebrates
Ampelisca tenuicornis Invertebrates
Ampharete finmarchica Invertebrates
Amphiura filiformis Invertebrates
Asterias rubens Invertebrates
Diplocirrus glaucus Invertebrates
Iphinoe serrata Invertebrates
Liocarcinus depurator Invertebrates
Maldane glebifex Invertebrates
Mediomastus fragilis Invertebrates
Mysella bidentata Invertebrates
Ninoe armoricana Invertebrates
Ophiura albida Invertebrates
Owenia fusiformis Invertebrates
Pagurus bernhardus Invertebrates
Pariambus typicus Invertebrates
Pholoe inornata Invertebrates
Scoloplos armiger Invertebrates
Terebellides stroemii Invertebrates
Thyasira flexuosa Invertebrates
Virgularia mirabilis Invertebrates

Vegetation types

Relation to vegetation types (syntaxa)

Not available

Other classifications

Not available
European Environment Agency (EEA)
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1050 Copenhagen K
Denmark
Phone: +45 3336 7100