Rockpooling destination: St. Loy, Cornwall October 2014 - Mid shore and rockpools

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 (see previous post), increasing within the rockpools, crevices and gullies of the mid and lower shore bedrock.

Barnacle communities characterise much of the upper and mid shore, inter-dispersed by coralline rockpools.

Habitat classification (Mid shore and rockpools):

Substrate	LR (Littoral rock)
Habitat	LR.HLR (High energy littoral rock)	FLR (Features of littoral rock)
Biotope complex	LR.HLR. MusB (Mussel and/or barnacle communities)	LR.FLR.Rkp (Rockpools)
Biotope		LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools)
Sub Biotope		LR.FLR.Rkp.Cor.Bif (Bifurcaria bifurcata in shallow eulittoral rockpools)	LR.FLR.Rkp.Cor.Cor (Coralline crust and Corallina officialis in shallow eulittoral rockpools)

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



Once the exposed bedrock is reached there is a stark increase in barnacle abundance, with much of the remaining fauna restricted to the crevices and coralline rockpools. Habitat classification: LR.HLR. MusB (Mussel and/or barnacle communities) EUNIS: A1.11

The lichen, Lichina pygmaea occurs as patches among the barnacles.

Lichina pygmaea

Common mussels (Mytilus edulis) occur within the crevices of the bedrock.

Individual robust fucoids occur among the barnacles. Now in October, these fucoids are showing signs of seasonal die back.






Dog whelks (Nucella lapillus) feed upon the barnacles and mussels.



The deep groove at the bottom of the shells' opening is where the siphon comes out of.  It is   this siphon that the dog whelk uses to 'sniff out' food.

Barnacles and small periwinkles (Melarhaphe neritoides).


A coralline rockpool within the barnacle community. Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools) EUNIS:A1.411 and  LR.HLR. MusB (Mussel and/or barnacle communities) EUNIS: A1.11

A shallow coralline rock pool dominated by pink corallinaceae crust on the upper mid shore.

A coralline rockpool on the mid shore.

A coralline rock pools with corallinaceae crusts, coral weed (Corallina officinalis) and a variety of red seaweeds on the lower shore. Habitat classification:  Coralline crusts and Corallina officinalis in shallow eulittoral rockpools(LR.FLR.Rkp.Cor.Cor) EUNIS: A1.4111



Corallinaceae crusts have formed where there is continual runoff from a rockpool above.


A coralline rockpool of the lower shore dominated by Corallina officinalis. The brown forkingweed (Bifurcaria bifurcata) also occurs and is charecteristic of the sub biotope LR.FLR.Rkp.Cor.Bif (Bifurcaria bifurcata in shallow eulittoral rockpools) EUNIS: A1.4113


A coralline rockpool of the lower shore dominated by Corallina officinalis with brown forkingweed (Bifurcaria bifurcata).


A coralline rockpool of the lower shore dominated by Corallina officinalis with brown forkingweed (Bifurcaria bifurcata).


A coralline rockpool of the lower shore with brown forkingweed (Bifurcaria bifurcata).


Corallina officinalis within a coralline rockpool.


Snakelocks anemone (Anemonia viridis) within a coralline rockpool.



Coral weed within a coralline rockpool.




A coralline rockpool. The sides of the rockpool are covered by corallinaceae crusts, clumps of coral weed (Corallina officinalis) sprout up like pink trees, Ulva sp often occur within these pools as does the brown forking weed (Bifurcaria bifurcata). On some coasts you may also encounter Codium fragile. Limpets (Patella sp) are also common within these rockpools. Habitat classification:LR.FLR.Rkp.Cor.Cor (Coralline crust and Corallina officinalis in shallow eulittoral rockpools) EUNIS: A1.4111.



A coralline rockpool. The sides of the rockpool are covered by corallinaceae crusts, clumps of coral weed (Corallina officinalis) sprout up like pink trees, Ulva sp often occur within these pools as does the brown forking weed (Bifurcaria bifurcata). On some coasts you may also encounter Japweed (Sargassum muticum) Limpets (Patella sp) and blenny are also common within the larger rockpools. Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools).