Friday, 6 March 2015

Rockpooling destination: St. Loy, Cornwall October 2014 - Supralittoral - Upper shore




The shore is a high energy environment, comprised of boulders and bedrock, with crevices, rock pools and gullies.

 
Fauna are relatively sparse among the spralittoral and upper shore boulders, increasing within the rockpools, crevices and gullies of the mid and lower shore bedrock.

The upper most shore is charecterised by lichen communities, whilst barnacle communities occur across the rest of the shore, inter-dispersed by coralline rockpools and as the lower shore is reached, robust fucoids and red seaweeds come to dominate.


A river flows onto the shore and beneath the boulders, until it emerges again on the shore, this time marked by an increase in ephemeral green algae.

Where conditions are sheltered enough, a strandline of kelp occurs.







Habitat classification: (Supralittoral - Upper shore)


Habitat
LR.HLR (High energy littoral rock)
FLR (Features of littoral rock)
LS.LSa (Littoral sand)
Biotope complex
LR.HLR. MusB (Mussel and/or barnacle communities)
LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock).
LR.FLR.Eph (Ephemeral green or red seaweed communities
LS.LSa.St (Strandline)
Biotope

LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock)
LR.FLR.Lic.Ver (Verrucaria Maura on littoral fringe rock)
LR.FLR.Eph (Ephermeral green or red seaweeds (Fresh water or sand influenced)

Sub Biotope


LR.FLR.Liv.VerB (Verrucaria maura and sparse barnacles on exposed littoral fringe rock)
LR.FLR.Lic.Ver.Ver (Verrucaria maura on very exposed to very sheltered
upper littoral fringe rock)






Below are images of some of organisms you may encounter whilst rock pooling in these habitats:


The exposed nature of the shore leads to an extended lichen zone. Habitat classification: LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock) ENUI.11S: B3 and LR.HLR. MusB (Mussel and/or barnacle communities) EUNIS: A1.11.

A variety of grey and yellow lichens occur on the boulders within the supra littoral. Habitat classification: LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock) EUNIS: B3.111.

Below the grey and yellow lichens the black, Tar lichen (Verrucaria maura) covers the rock . Habitat classification: LR.FLR.Lic.Ver (Verrucaria maura on litto.ral fringe rock) EUNIS: B3.113
Faunal diversity is low among the boulders  and principally constitute Verrucaria maura and periwinkles. Here a rough periwinkle (Littorina sp) seeks refuge on the underside of a boulder. Habitat classification: A variant of LR.FLR.Lic.Ver.Ver (Verrucaria maura on very exposed to sheltered upper littoral fringe rock).






A limpet, Periwinkle (Littorina sp) and sparse barnacles occur below the more barren LR.LIC.Ver.Ver. Habitat classification:A variant of  LR.FLR.Liv.VerB (Verrucaria maura and sparse barnacles on exposed littoral fringe rock) EUNIS: B3.1131
A rough periwinkle (Littorina compressa), small periwnkles (Melarhaphe neritoides) and barnacles seek refuge from wave exposure by pushing them selves up into each knock and cranny that the uneven texture of the boulder face provides.

Rough periwinkles (Littorina sp) aggregate between boulders.

A rough periwinkle (Littorina saxatilis agg.) and small periwinkles (Melarhaphe neritoides).

A rough periwinkle (Littorina compressa)
Further down the shore the Verrucaria spp occurs as patches, and barnacle and limpet abundance increase. Other species, such as dog whelk (Nucella lapillus) also occur. Habitat classification: LR.HLR. MusB (Mussel and/or barnacle communities) EUNIS: A1.11.
Limpets
On exposed shores species aggregate on the leeward side of boulders to avoid  being dislodged by wave action.
Thick topshells (Osilinus lineatus) aggregate among more sheltered boulders that are in the lee of bedrock formations.
Thick topshells (Osilinus lineatus), beadlet anemones (Actinia equina), barnacles and limpets charecterise the upper shore barnacle communities.
An encrusting red grows on a boulder.
Catenella caespitosa forms a turf  in the damp between two boulders.

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