Skip to Content

Marine Habitat Classification

Description of biotope or habitat type

To understand more about what this page is describing, see How to use the classification. See also How to cite.

   Laminaria saccharina park on very sheltered lower infralittoral rock

Physical habitat description

Salinity Full (30-35 ppt)
Wave exposure Sheltered, Very sheltered
Tidal streams Weak (>1 kn), Very weak (negligible)
Substratum Bedrock; boulders and cobbles
Zone Infralittoral - lower
Depth Band 5-10 m, 10-20 m
Other Features Also on vertical rock.

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 IR.LIR.K.Lsac.Pk <I>Laminaria saccharina</I> park on very sheltered lower infralittoral 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'
  • Predicted extent of the level 3 (for sublittoral rock & deep sea) or 4 (for sublittoral sediment) habitat

Point data based on records in the UK Marine Recorder Snapshot. Predicted habitat extent is from UKSeaMap.


Silty bedrock or boulders with a Laminaria saccharina park (often the cape-form). Beneath the canopy, the rock is covered by encrusting coralline algae, and the urchin Echinus esculentus is often present. Due to the amount of silt cover on the rock and the reduced light intensity beneath the broad-fronded kelp, only a few red seaweeds typically survive, the most common species being Phycodrys rubens, Delesseria sanguinea, Bonnemaisonia spp. and Brongniartella byssoides. The brown seaweeds Dictyota dichotoma and Cutleria multifida may be present in low abundance. Compared to the kelp forest zone above (Lsac.Ft) both the kelp and other seaweeds are sparse (Occasional). The most conspicuous animals are large solitary ascidians, particularly Ascidia mentula and Ciona intestinalis, together with the smaller Clavelina lepadiformis. In general, the faunal component of this biotope is similar to other sheltered kelp biotopes and includes a variety of mobile crustaceans such Carcinus maenas and Pagurus bernhardus, the keelworm Pomatoceros spp., terebellid worms, echinoderms Asterias rubens, Ophiothrix fragilis and the featherstar Antedon bifida. The hydroid Kirchenpauria pinnata, although only rare is often found in the kelp park along with the top shell Gibbula cineraria and the barnacle Balanus crenatus.


L. saccharina park can be found below a similar forest (Lsac.Ft) where suitable hard substrata exist or on isolated rock exposures surrounded by sediment communities. It may also occur below a zone of mixed Laminaria hyperborea and L. saccharina forest (LhypLsac). L. saccharina can also form a band below L. hyperborea forest (Lhyp.Ft) where some shelter from wave-action is afforded with depth (L. saccharina is not tolerant of surge), or more likely where L. hyperborea has been grazed out (below Lhyp.GzFt) since L. saccharina grows far quicker than L. hyperborea. Where such a narrow band occurs it is generally less silted than that found below Lsac.Ft in much more sheltered conditions. A range of sheltered circalittoral biotopes may occur on any deeper rock below (e.g. AntAsH, AmenCio and ModHAs).

Temporal variation


Characterising species

Taxon Relative importance of taxon for defining this community (%) Typical abundance - SACFOR scale % of core records where taxon was recorded
Kirchenpaueria pinnata 1 Occasional 21-40 %
Caryophyllia smithii 1 Occasional 21-40 %
Terebellidae 1 Occasional 21-40 %
Pomatoceros triqueter 3 Frequent 41-60 %
Balanus crenatus 1 Frequent 21-40 %
Pagurus bernhardus 4 Occasional 41-60 %
Carcinus maenas 1 Occasional 21-40 %
Gibbula cineraria 2 Occasional 41-60 %
Antedon bifida 2 Occasional 21-40 %
Asterias rubens 6 Occasional 61-80 %
Ophiothrix fragilis 2 Occasional 41-60 %
Echinus esculentus 8 Occasional 61-80 %
Clavelina lepadiformis 2 Occasional 21-40 %
Ciona intestinalis 1 Occasional 21-40 %
Ascidia mentula 5 Occasional 41-60 %
Bonnemaisonia asparagoides 1 Occasional 21-40 %
Bonnemaisonia hamifera 2 Common 21-40 %
Corallinaceae 9 Frequent 61-80 %
Delesseria sanguinea 2 Occasional 21-40 %
Phycodrys rubens 2 Frequent 21-40 %
Brongniartella byssoides 2 Occasional 21-40 %
Cutleria multifida 1 Frequent 21-40 %
Dictyota dichotoma 2 Occasional 21-40 %
Laminaria saccharina 18 Occasional 81-100 %

Similar biotopes or habitat types

L. saccharina and L. hyperborea co-dominantes this biotope (both Frequent). Generally less silted than Lsac.Pk and there tends to be a greater variety of species, particularly more red seaweeds.

Occurs in shallower water where L. saccharina is typically Abundant and there is a greater variety and higher abundance of red seaweeds.

This biotope is very impoverished even compared to Lsac.Pk and the kelp may be absent altogether. The diversity of red seaweeds are much lower than in the park with a dominance of Corallinacea (Common) even though small turf of foliose red seaweeds and brown seaweeds like Desmarestia spp. and Chorda filum may occur. Halichondria panicea (Rare) is the likely to be only sponge present compared to Lsac.Pk, which have a higher diversity of sponges (Porifera).

Back to top