Biogenic reefs within the MNCR biotope classification

Links to MNCR Biotope Classification

The table below shows those MNCR biotopes which can be considered as biogenic reefs. It also includes a number of biotopes which were considered, but which are do not regarded in this report as biogenic reefs, along with reasons.

MNCR biotopes which are potentially relevant to this report with comments relating to their status as biogenic reefs. Biotopes listed are those where the dominant organism is one of the five species considered in detail in this report: Sabellaria alveolata, S. spinulosa, Modiolus modiolus, Mytilus edulis and Serpula vermicularis.

Sabellaria alveolata
Higher code			Biotope code	Biotope	Comments
MLR.Sab			Littoral Sabellaria (honeycomb worm) reefs
MLR.Sab			Salv	Sabellaria alveolata reefs on sand-abraded eulittoral rock	Biogenic reef Sabellaria can perform important stabilisation of habitat usually involving significantly raised structures.
Sabellaria spinulosa
Higher code			Biotope code	Biotope	Comments
MIR			MODERATELY EXPOSED INFRALITTORAL ROCK
MIR.SedK			Sand or gravel-affected or disturbed kelp and seaweed communities
MIR.SedK			SabKR	Sabellaria spinulosa with kelp and red seaweeds on sand- influenced infralittoral rock	Not biogenic reef. Many associated species capable of growing on the rock whether the Sabellaria are there or not, and no significant raised reef area.
MCR			MODERATELY EXPOSED CIRCALITTORAL ROCK
MCR.CSab			*Circalittoral Sabellaria* reefs**
MCR.CSab			Sspi	Sabellaria spinulosa crusts on silty turbid circalittoral rock	Not biogenic reef. Many associated species capable of growing on the rock whether the Sabellaria are there or not, and usually no significant raised reef area.
MCR.As			Ascidian communities (silt influenced)
MCR.As	MolPol.Sab			Dense ascidians, bryozoans, and hydroids on a crust of Sabellaria spinulosa on tide-swept circalittoral rock	Not biogenic reef. Many associated species capable of growing on the rock whether the Sabellaria are there or not, and usually no significant raised reef area.
CMX			CIRCALITTORAL MIXED SEDIMENTS
CMX			SspiMx	Sabellaria spinulosa and Polydora spp. on stable circalittoral mixed sediment	Biogenic reef - Sabellaria can perform important stabilising function on substratum.
Modiolus modiolus
Higher code			Biotope code	Biotope	Comments
MIR			SHELTERED INFRALITTORAL ROCK
MCR.M			Mussel beds (open coast circalittoral rock/mixed substrata)
MCR.M			ModT	Modiolus modiolus beds with hydroids and red seaweeds on tide-swept circalittoral mixed substrata	Biogenic reef Modiolus creates important alteration of habitat and may form significantly raised structure.
SCR			SHELTERED CIRCALITTORAL ROCK
SCR.Mod			Sheltered Modiolus (horse-mussel) beds
SCR.Mod			ModCvar	Modiolus modiolus beds with Chlamys varia, sponges, hydroids and bryozoans on slightly tide-swept very sheltered circalittoral mixed substrata	Biogenic reef Modiolus creates important alteration of habitat and may form somewhat raised structure.
SCR.Mod			ModHAs	Modiolus modiolus beds with fine hydroids and large solitary ascidians on very sheltered circalittoral mixed substrata	Biogenic reef Modiolus creates important alteration of habitat and may form somewhat raised structure.
CMX			CIRCALITTORAL MIXED SEDIMENTS
CMX			ModMx	Modiolus modiolus beds on circalittoral mixed sediment	Biogenic reef Modiolus creates important alteration of habitat and may form significantly raised structure.
CMX			ModHo	Sparse Modiolus modiolus, dense Cerianthus lloydii and burrowing holothurians on sheltered circalittoral stones and mixed sediment	Clearly not biogenic reef.
Mytilus edulis
Higher code			Biotope code	Biotope	Comments
ELR			EXPOSED LITTORAL ROCK (mussel/barnacle shores)
ELR.MB			Mytilus (mussels) and barnacles
ELR.MB			MytB	Mytilus edulis and barnacles on very exposed eulittoral rock	Not biogenic reef. This is a typical rocky shore community. Mussels are rarely more than 2 layers deep.
MLR			MODERATELY EXPOSED LITTORAL ROCK (barnacle/fucoid shores)
MLR.MF			Mytilus (mussels) and fucoids (moderately exposed shores)
MLR.MF			MytFves	Mytilus edulis and Fucus vesiculosus on moderately exposed mid eulittoral rock	Not biogenic reef. Many species capable of growing on the rock whether the Mytilus are there or not (though there may be additional sediment dependent species); usually no significant raised reef area.
MLR.MF		MytFR		Mytilus edulis, Fucus serratus and red seaweeds on moderately exposed lower eulittoral rock	Not biogenic reef. As above.
MLR.MF		MytPid		Mytilus edulis and piddocks on eulittoral firm clay	Clearly not biogenic reef.
SLR		SHELTERED LITTORAL ROCK (fucoid shores)
SLR.MX		Mytilus (mussel) beds (mixed substrata)
SLR.MX		MytX		Mytilus edulis beds on eulittoral mixed substrata	Biogenic reef - Mytilus performs important stabilising function on substratum.
LMX		LITTORAL MIXED SEDIMENTS
LMX		Mytfab		Mytilus edulis and Fabricia sabella in poorly-sorted muddy sand or muddy gravel shores	Not biogenic reef - organisms perform some stabilising function on substratum but do not form substantial structures.
MIR		SHELTERED INFRALITTORAL ROCK
SIR.EstFa		Estuarine faunal communities (shallow rock/mixed substrata)
SIR.EstFa		MytT		Mytilus edulis beds on reduced salinity tide-swept infralittoral rock	Not biogenic reef. Many species capable of growing on the rock whether the Mytilus are there or not (though there may be additional sediment dependent species); usually no significant raised reef area.
MCR.M		Mussel beds (open coast circalittoral rock/mixed substrata)
MCR.M		MytHAs		Mytilus edulis beds with hydroids and ascidians on tide swept moderately exposed circalittoral rock	Not biogenic reef. Associated species almost all capable of growing on the rock whether the Mytilus are there or not, and usually no significant raised reef area.
IMX		INFRALITTORAL MIXED SEDIMENTS
IMX.EstMx		Estuarine sublittoral mixed sediments
IMX.EstMx		MytV		Mytilus edulis beds in variable salinity infralittoral mixed sediment	Biogenic reef - Mytilus performs important stabilising function on substratum; can be raised substantially above surrounding sediment.
Serpula vermicularis
Higher code			Biotope code	Biotope	Comments
CMS			CIRCALITTORAL MUDDY SANDS
CMS			Ser	Serpula vermicularis reefs on very sheltered circalittoral muddy sand	Biogenic reef Serpula creates important alteration of habitat and can form large, projecting structures.

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