Marine Atlantic infralittoral fine mud
Quick facts
Red List habitat type | code NEAA5.34 |
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Threat status | |
Europe | Near Threatened |
EU | Near Threatened |
Relation to |
|
Source | European Red List habitat factsheet |
European Red List of habitats reports | |
European Red List of habitats (Excel table) |
Summary
Shallow sublittoral muds, extending from the extreme lower shore to about 15-20 m depth in fully marine or near marine conditions, predominantly in extremely sheltered areas with very weak tidal currents. Such habitats are found in sealochs and some rias and harbours. In very shallow extremely sheltered very soft muds the lugworm Arenicola marina may form very conspicuous mounds and casts. At such sites, high densities of synaptid holothurians such as Labidoplax media and Leptosynapta bergensis occur. The sediment surfaces may become covered by a diatom film at certain times of the year. Mobile species are opportunistic scavengers and predators and include starfish (e.g. Asterias rubens), crabs and hermit crabs (e.g. Carcinus maenas and Pagurus bernhardus), flatfish and gobies (e.g. Pomatoschistus minutus).
Sheltered sediments such as these are characterized by fine grain size, low porosity, generally low permeability (and hence high water content), high sediment stability (due to cohesion), a low oxygen content and highly reducing conditions. The mud surface is oxygenated. However, in fine muds, the anoxic reducing layer is likely to be very close to the surface, often less than 1cm. Bioturbation by burrowing species, results in mobilisation of the sediment and nutrients from deeper sediment to the surface, making nutrients available to surface dwelling organisms. In addition, continued irrigation of their burrows by Arenicola marina and Leptosynata sp. transports oxygenated water into the sediment, resulting in oxygenated micro-environments in the vicinity of their burrows.
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 indiceswhich 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. Key driving influences and output processes of shallow sublittoral mud habitats that are likely to be sensitive to pressures and may be useful for monitoring to identify anthropogenic causes of change include habitat structure changes, removal of particular species such as those which are key in bioturbation and biodeposition, or nutrient and biogeochemical cycling, changes in siltation rates and organic enrichment.
Threat status
Synthesis of Red List assessment
EU | |
Red List Category | Red List Criteria |
Near Threatened | C/D1 |
Europe | |
Red List Category | Red List Criteria |
Near Threatened | C/D1 |
Confidence in the assessment
Pressures and threats
- Urbanisation, residential and commercial development
- Discharges
- Biological resource use other than agriculture & forestry
- Marine and Freshwater Aquaculture
- Fishing and harvesting aquatic resources
- Professional active fishing
- Benthic or demersal trawling
- Pollution
- Nutrient enrichment (N, P, organic matter)
- Natural System modifications
- Human induced changes in hydraulic conditions
- Modification of hydrographic functioning, general
Habitat restoration potential
Recovery times following oxygen depletion and pollution has been investigated in several studies of the Gullmarsfjord, Sweden and reported to be between 2-8 years. Isolation is also a factor. Recruitment to isolated habitats, such as sea lochs, from outside the area may take some time and be dependant on sporadic events such as storms.
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
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
- 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
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 | 2,738.38 | 183 | >710 | 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+ | >183 | >710 | 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 |
---|---|---|
Pomatoschistus minutus | Common goby | Fishes |
Abra nitida | Invertebrates | |
Aphelochaeta marioni | Invertebrates | |
Arenicola marina | Invertebrates | |
Asterias rubens | Invertebrates | |
Carcinus maenas | Invertebrates | |
Cerastoderma edule | Invertebrates | |
Hydrobia ulvae | Invertebrates | |
Leptosynapta bergensis | Invertebrates | |
Liocarcinus depurator | Invertebrates | |
Ocnus planci | Invertebrates | |
Ophiodromus flexuosus | Invertebrates | |
Pagurus bernhardus | Invertebrates | |
Philine aperta | Invertebrates | |
Virgularia mirabilis | Invertebrates |
Legal status
Relation to other habitat types mentioned in legal instruments
Legal text | Annex | Name in legal text | Code in legal text |
Habitat type relationship |
More information |
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Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora - consolidated version 01/01/2007 | Annex I: natural habitat types of community interest whose conservation requires the designation of special areas of conservation | Large shallow inlets and bays | 1160 | Overlap | http://ec.europa.eu/environm...rective/index_en.htm |