Seapens and burrowing megafauna in Atlantic circalittoral fine mud
Quick facts
EUNIS habitat type | code MC6216 |
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Relation to | Resolution 4 habitat type (used for designation of Emerald sites) |
Description (English)
Plains of fine mud at depths greater than about 15 m may be heavily bioturbated by burrowing megafauna; burrows and mounds may form a prominent feature of the sediment surface with conspicuous populations of seapens, typically Virgularia mirabilis and Pennatula phosphorea. The burrowing crustacea present typically include Nephrops norvegicus, which is frequently recorded from surface observations although grab sampling may fail to sample this species. Indeed, some forms of sampling may also fail to indicate seapens as characterising species. This biotope also seems to occur in deep offshore waters in the North Sea, where densities of Nephrops norvegicus may reach 68 per 10 per square metre. (see Dyer et al. 1982, 1983), and the Irish Sea. The burrowing anemone Cerianthus lloydii and the ubiquitous epibenthic scavengers Asterias rubens, Pagurus bernhardus and Liocarcinus depurator are present in low numbers in this biotope whilst the brittlestars Ophiura albida and Ophiura ophiura are sometimes present, but are much more common in slightly coarser sediments. Low numbers of the anemone Pachycerianthus multiplicatus may also be found, and this species, which is scarce in the UK, appears to be restricted to this habitat (Plaza & Sanderson 1997). The infauna may contain significant populations of the polychaetes Pholoe spp., Glycera spp., Nephtys spp., spionids, Pectinaria belgica and Terebellides stroemi, the bivalves Nucula sulcata, Corbula gibba and Thyasira flexuosa, and the echinoderm Brissopsis lyrifera.
Situation: These soft mud habitats occur extensively throughout the more sheltered basins of sealochs and voes (narrow inlets) and are present in quite shallow depths (as little as 15 m) in these areas probably because they are very sheltered from wave action.
Source: EUNIS habitat classification
Legal status
Relation to other habitat types mentioned in legal instruments
Vegetation types
Relation to vegetation types (syntaxa)
Not availableSpecies mentioned in habitat description
Species scientific name | English common name | Species group |
---|---|---|
Asterias rubens | Invertebrates | |
Liocarcinus depurator | Invertebrates | |
Nephrops norvegicus | Invertebrates | |
Ophiura albida | Invertebrates | |
Ophiura ophiura | Invertebrates | |
Pachycerianthus multiplicatus | Invertebrates | |
Virgularia mirabilis | Invertebrates |
Other classifications
Classification | Code | Habitat type name | Relationship type |
---|---|---|---|
EUNIS Habitat Classification 2007 (revised descriptions 2012) | A5.361 | Seapens and burrowing megafauna in circalittoral fine mud | same |
History
Classification | Code | Habitat type name | Relationship type | Comment |
---|---|---|---|---|
EUNIS Habitat Classification 200410 | A5.361 | Seapens and burrowing megafauna in circalittoral fine mud | same | |
EUNIS Habitat Classification 200308 | A4.362 | Seapens and burrowing megafauna in circalittoral soft mud | same | |
EUNIS Habitat Classification 200202 | A4.362 | Seapens and burrowing megafauna in circalittoral muds | same | |
EUNIS Habitat Classification 199910 | A4.362 | Seapens and burrowing megafauna in circalittoral muds | same | |
EUNIS Habitat Classification 199811 | A4.82 | Virgularia mirabilis and Pennatula phosphorea and burrowing megafauna of circalittoral muds | same | |
EUNIS Habitat Classification 199712 | A6.32 | Seapens Nephrops norvegicus and burrowing megafauna of circalittoral muds | same | |
MNCR BioMar 97.06 (Britain & Ireland) | CMU.SpMeg | Seapens and burrowing megafauna in circalittoral soft mud | same | |
MNCR BioMar 96.7 (Britain & Ireland) | CMU.SpNep | same |