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Marine Habitat Classification


Description of biotope or habitat type

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   Fucus ceranoides on reduced salinity eulittoral rock


Physical habitat description

Salinity Reduced (18-30ppt), Variable (18-35 ppt)
Wave exposure Very sheltered, Extremely sheltered
Tidal streams
Substratum Bedrock; boulders
Zone Eulittoral - upper, Littoral fringe
Depth Band
Other Features

Download comparative physical and biological data. The comparative tables enable a rapid comparison of the species composition and principal physical characteristics between a given set of biotopes.

Distribution of habitat LR.LLR.FVS.Fcer <I>Fucus ceranoides</I> on reduced salinity eulittoral rock

  • Records used to define the biotope (core records)
  • Other records assigned to this biotope, marked as 'certain'
  • Other records assigned to this biotope, marked as 'uncertain'

Point data based on records in the UK Marine Recorder Snapshot.

Description

Very sheltered to extremely sheltered bedrock and stable boulders in the eulittoral zone that are subject to reduced salinity and characterised by the wrack Fucus ceranoides. Species richness is typically low in this biotope. The green seaweeds Ulva intestinalis and Ulva lactuca may be present together with the crab Carcinus maenas and the occasional barnacle Austrominius modestus and Semibalanus balanoides.

Situation

As F. ceranoides is more tolerant of reduced salinity than the other fucoids, F. ceranoides tends to replace the wracks Fucus spiralis, Fucus vesiculosus and Ascophyllum nodosum towards the upper reaches of estuaries and sea lochs or in areas with freshwater influence. This biotope may, however, still contain other fucoids, although F. ceranoides always dominates. This biotope is often found on artificial substrata such as sea defences or bridge supports.

Temporal variation

Unknown.

Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Fucus ceranoides 66 Common 81-100%
Ulva intestinalis 13 Frequent 41-60%
Carcinus maenas 4 Occasional 41-60%
Austrominius modestus 3 Occasional 21-40%
Semibalanus balanoides 2 Occasional 21-40%
Ulva lactuca 2 Occasional 21-40%

Similar biotopes or habitat types

Not applicable or unknown.

Classification history of this biotope or habitat type

Classification version Code
1997 (97.06) SLR.Fcer
1997 (97.06) SLR.FcerX
1995 LRK.FCER

Photos

LR.LLR.FVS.Fcer Fucus ceranoides on reduced salinity eulittoral rock, Loch Sunart. Rohan Holt© JNCC
LR.LLR.FVS.Fcer Fucus ceranoides on reduced salinity eulittoral rock, Loch Sunart. Rohan Holt© JNCC
LR.LLR.FVS.Fcer Fucus ceranoides on reduced salinity eulittoral rock, W of Bradwell Marina, River Blackwater. Chris Emblow© JNCC
LR.LLR.FVS.Fcer Fucus ceranoides on reduced salinity eulittoral rock, W of Bradwell Marina, River Blackwater. Chris Emblow© JNCC
LR.LLR.FVS.Fcer Fucus ceranoides on reduced salinity eulittoral rock, Lerryn Creek, River Fowey. Keith Hiscock© JNCC
LR.LLR.FVS.Fcer Fucus ceranoides on reduced salinity eulittoral rock, Lerryn Creek, River Fowey. Keith Hiscock© JNCC

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