Tuesday, 9 December 2014

Rockpooling destination: NW Shetland, September 2014

The exposed rocky shore consists of a steeply sloping cobble cove surrounded by cliffs and caves.
The cobbles support little wildlife, that which does occur is concentrated within the strand line.
The stable cliffs support a community typical of high energy environments with barnacles, limpets, periwinkles, dog whelks and anemones.

Habitat classification:


Biotope complex
LR.HLR. MusB (Mussel and/or barnacle communities)
LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock).
LS.LSa (Littoral sand)
Biotope

LR.FLR.Lic.Ver (Verrucaria Maura on littoral fringe rock)
LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock)
LS.LSa.St (Strandline)


The rocky shore is made up of  an exposed cobble beach and surrounding cliffs. Habitat classification: LR.HR (High energy littoral rock)


Waves on this exposed shore have created the steep inclination of the cobbles and created a succession of strandlines that mark a succession of high tide marks. Habitat classification: LR.HL (High energy littoral rock) and LS. St (Strandline).


The power of the waves can also be seen on the cliff bases which have become smooth and 'cut into'  by the waves throwing cobbles and boulders at their base. Due to this continual process many organisms live within the refuge of crevices. 
Several communities occur on the cliffs. At the top of the cliff  is a community of yellow and grey lichens, below which is the black tar lichen (Verrucaria mauraand then a community dominated by barnacles. Habitat classification: LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock), LR.FLR.Lic.Ver (Verrucaria Maura on littoral fringe rock) and  LR.HLR. MusB (Mussel and/or barnacle communities).



Yellow and grey lichens cover the splash zone of the cliff, below the black rock marks the community charecterised by V. maura and is where the rough periwinkle (Littorina saxatilis agg) and small periwinkles (Melarhaphe neritoidesbegin to occur, further down where the black gives way to brown marks the transition to the barnacles dominated community which supports the periwinkles and limpets.

Small periwinkles (M. neritoides)
within the V. maura community.
Rough periwinkle (L. saxatilis agg) and small periwinkle (M. neritoides)


Rough periwinkles (L. saxatilis agg.) seek refuge within a crevice.
Barnacles and rough periwinkles (L. saxatilis agg.) with in the barnacle community.



Barnacles


Common limpets (Patella vulgata) and barnacles


Dog whelks (Nucella lapillusand barnacles with patches of V maura

Dog whelks (N. lapillusand barnacles



Beadlet anemones (Actina equina) and barnacles.




The strandline is made up of old seaweed, drift wood, plastic bouys and birch bark from the North.


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