Tuesday 16 June 2015

Rockpooling Destination: Treen, Cornwall April 2015

The shore comprises shelving bedrock with gullies and rockpools. Lichens communities dominate large areas of the shore, eventually giving way to barnacle and mussel/fucoid communities. Rockpools occur throughout the shore, varying in species composition depending on their level of exposure to air and wave.

Below are images of the habitats and organisms you  may encounter whilst rockpooling on this shore:




The shore comprises shelving bedrock with gullies and rockpools. Lichens communities dominate large areas of the shore before they give way to barnacle and mussel/fucoid communities. Rockpools occur throughout the shore, varying in species composition depending on their level of exposure to air and wave. Habitat classification: LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock) EUNIS B3.111, LR.FLR.Lic.Ver (Verrucaria Maura on littoral fringe rock) EUNIS: B3.113, LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools)  EUNIS: A1.4111, LR.HLR. MusB (Mussel and/or barnacle communities) EUNIS: A1.11.

 Yellow and grey lichens cover the spuralittoral bedrock, whilst Tar lichen (Verrucaria Maura) domaintes littoral fringe bedrock.  Habitat classification: LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock) EUNIS B3.111.



Below the yellow and grey lichens, Tar lichen (Verrucaria Maura) covers littoral fringe bedrock. Rough periwinkles (Littorina spp) and small periwinkles (Melarhaphe neritoides) occur and in damp crevices patches of the ephemeral green algae, Ulva spp (Formally Entomoropha spp.) Habitat classification:LR.FLR.Lic.Ver (Verrucaria Maura on littoral fringe rock) EUNIS: B3.113.


Small periwinkles (Melarhaphe neritoides) and the lichens  Verrucaria maura and Caloplaca marina.



M. neritoides and   V.maura 

  V.maura , M. neritoides and  sparse barnacles. Habitat classification: LR.FLR.Lic.Ver.B (Verrucaria Maura and sparse barnacles on exposed littoral fringe rock) EUNIS: B3.1131.

Sparse barnacles and V. maura.

The rockpools within the Verrucaria maura biotope support relatively few species, in part due to the grazing of the periwinkles and the environmental fluctuations experienced within rockpools at this height on the shore. Habitat classification: LR.FLR.Rkp (Rockpools) EUNIS: A1.41.
Below the Verrucaria maura biotope rockpools of the upper shore are dominated by Corallinaceae crusts. Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools) EUNIS: A1.411.
Barnacle density begins to increase as you descend down the shore. Barnacles and Melarhaphe neritoides. Habitat classification: LR.HLR. MusB (Mussel and/or barnacle communities), EUNIS: A1.11.

The lichen, Lichina pygmaea occurs as a band among the barnacles communities of the upper shore. Habitat classification: LR.HLR.MusB.Cht.Lpyg (Chthamalus spp. and Lichina pygmaea on steep exposed upper eulittoral rock) EUNIS: A1.1122

Lichina pygmaea  and Melarhaphe neritoides.

Lichina pygmaea

Common blue mussels (Mytilus edulis) occur within the crevices, covered by a red seaweed (Porphyra spp).


On the mid shore the mussel abundance increases, although their distribution continues to be confined to crevices among the barnacles. Habitat classification: LR.HLR.MusB.MytB (Mytilus edulis and barnacles on very exposed eulittoral rock) EUNIS: A1.111.

Barnacles, M. edulis and Porphyra spp.

M. edulis aggregate within crevices surrounded by barnacles and common limpets (Patella vulgata).

M. edulis and Porphyra spp.

M. edulis and Porphyra spp.
On sheltered aspects on the shore fucoids are interspersed among the barnacle and mussel community.  

Barnacles, Melarhaphe neritoides and Patella vulgata.



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