Friday 30 August 2013

Rock pooling destination: Eilean Feoir, Eigg May 2013

The shore near Eilean Feoir comprises bedrock and boulders with rock pools of varying sizes. Lichens occur in the splash zone and extend into the upper shore with channel wrack and periwinkles. The mid to lower shore is covered by fucoids beneath which an understory community of gastropods, anemones, barnacles, crustaceans and saeweeds exists. Many of these species also occur within the large rockpools with the addition of a wider variety of red seaweeds, anemones and  encrusting fauna.


Habitats classification: 
Substrate
LR (Littoral rock)
Habitat
LLR (Low energy littoral rock)
FLR (Features of littoral rock)
Biotope complex
LR.LLR.F (Fucoids on sheltered marine shores)
Rkp (Rockpools)
LR.FLR.Lic (Lichens on supralittoral rock)
Biotope
LR.LLR.F.Pel (Pelvetia canaliculata on sheltered littoral fringe rock)
LR.LLR.F.Fspi (Fucus spiralis on sheltered upper eulittoral rock)
LR.LLR.F.Asc (Ascophyllum nodosum on very sheltered mid eulittoral rock)

LR.FLR.Lic.Ver (Verrucaria Maura on littoral fringe rock)
Below are images of some of the organisms you may encounter whilst rock pooling in these habitats:


 The rocky shore contains the biotope complexes LR.FLR.Lic (Lichens on supralittoral rock), LR.LLR.F (Fucoids on sheltered marine shores) and LR.FLR.Rkp (Rockpools).


 Lichens occur on supralittoral rock. Habitat classification: LR.FLR.Lic (Lichens on supralittoral rock).


Tar lichen (Verrucaria maura) covers the upper shore and characterises the biotope LR.FLR.Lic.Ver (Verrucaria maura on littoral fringe rock) that occurs within the broader biotope complex LR.FLR.Lic (Lichens on supralittoral rock).


 Channel wrack (Pelvetia canaliculata) on the upper shore. Pelvetia canaliculata characterises the biotope LR.LLR.F.Pel (Pelvetia canaliculata on sheltered littoral fringe rock) that occurs within the broader biotope complex of LR.LLR.F (Fucoids on sheltered marine shores).


  The rough periwinkle (Littorina saxatilis) seeks refuge from the sun in the shade between boulders of the upper shore. Habitat classification: LR.LLR.F.Pel (Pelvetia canaliculata on sheltered littoral fringe rock).


Channel wrack (Pelvetia canaliculata) and Spiral wrack (Fucus spiralis) on the upper-mid shore. Fucus spiralis characterises the biotope LR.LLR.F.Fspi (Fucus spiralis on sheltered upper eulittoral rock) that occurs within the broader biotope complex of LR.LLR.F (Fucoids on sheltered marine shores).


  Channel wrack (Pelvetia canaliculata) and Spiral wrack (Fucus spiralis) surround a rock pool of the upper-mid shore. Fucus spiralis in its reproductive phase with swollen ends to the frond known as receptacles that contain the conceptacles from which gametes are released. Habitat classification: LR.LLR.F.Fspi (Fucus spiralis) on sheltered upper eulittoral rock.


  Regrowth of Spiral wrack (Fucus spiralis). Habitat classification: LR.LLR.F.Fspi (Fucus spiralis) on sheltered upper eulittoral rock.


  Dog whelks (Nucella lapillus) amongst Spiral wrack (Fucus spiralis). Habitat classification: LR.LLR.F.Fspi (Fucus spiralis) on sheltered upper eulittoral rock.


   Beneath the fronds of Fucus spiralis are common limpets (Patella vulgata) and barnacles. Habitat classification: LR.LLR.F.Fspi (Fucus spiralis) on sheltered upper eulittoral rock.


   Beneath the fronds of Fucus spiralis are beadlet anemones (Actinia equina) and sparse barnacles. Habitat classification: LR.LLR.F.Fspi (Fucus spiralis) on sheltered upper eulittoral rock.


   Egg wrack (Ascophyllum nodosum) and the epiphyte Polysiphonia lanosa occur on the mid shore below the band of Fucus spiralis. Ascophyllum nodosum charecterises the biotope LR.LLR.F.Asc (Ascophyllum nodosum on very sheltered mid eulittoral rock) that occurs within the biotope complex of LR.LLR.F (Fucoids on sheltered marine shores).


The transition from the biotope : LR.LLR.F.Fspi (Fucus spiralis on sheltered upper eulittoral rock) to LR.LLR.F.Asc (Ascophyllum nodosum on very sheltered mid eulittoral rock) can clearly be seen. Such a distribution is driven by competition between species and their physiological tolerance to the environmental gradients experienced across the shore.


A juvenile crab, flat periwinkle (Littorina obtusata) and green seaweed, Cladophora rupestris occur beneath the Egg wrack (Ascophyllum nodosum). Habitat classification: LR.LLR.F.Asc (Ascophyllum nodosum on very sheltered mid eulittoral rock).


   Seaweed diversity increases within the refuge of the larger rock pools. Habitat classification: LR.FLR.Rkp (Rockpools).


  Pebbles, Cobbles and boulders form the principle substrate within the rock pools and are colonised by bread crumb sponge (Halichondria (Halichondria) panicea), seaweeds and a variety of faunal turfs. Habitat classification: LR.FLR.Rkp (Rockpools).
 Juvenile barnacles cover the boulder and extend into the rock pool. The submerged section of the boulder is encrusted by coralline crusts; their upper limit on the boulder marking the lowest water levels experienced by the rock pool. Further down in the pool green algae occur and a beadlet anemone (Actinia equina). Above the water line a common limpet (Patella vulgata) wait motionless for the tide to return. Habitat classification: LR.FLR.Rkp (Rockpools).
Coralline crusts cover the submerged boulders of a rock pool. Habitat classification: LR.FLR.Rkp (Rockpools).




An under-boulder community within a rock pool. Habitat classification: LR.FLR.Rkp (Rockpools).


An under-boulder community within a rock pool. Habitat classification: LR.FLR.Rkp (Rockpools).
An under-boulder community within a rock pool. Habitat classification: LR.FLR.Rkp (Rockpools).
Juvenile anomiidae and spirorbidae on the under- side of a boulder within a rock pool. Habitat classification: LR.FLR.Rkp (Rockpools).


Snakelocks anemone (Anemonia viridis) within a rock pool. Habitat classification: LR.FLR.Rkp (Rockpools).


Snakelocks anemone (Anemonia viridis) attached to seaweed within a rock pool. Habitat classification: LR.FLR.Rkp (Rockpools).





Saturday 24 August 2013

Rock pooling destination: Cathedral Cave, Eigg May 2013

The shore comprises a bedrock platform that contains a number of rock pools before dropping off towards the low tide mark.


Fucoids and barnacles form a patch-work like distribution across the shore, within which rock pools occur. The shallow rock pools are dominated by coralline crusts whilst the deeper pools have a variety of seaweeds.

Habitat classification:

Substrate
LR (Littoral rock)
Habitat
MLR (Moderate energy littoral rock)
FLR (Features of littoral rock)
Biotope complex
BF (Barnacles and fucoids on moderately exposed shores)
Rkp (Rockpools)
Biotope
LR.LMR.BF.PelB   (Pelvetia canaliculata and barnacles on moderately exposed shores)
LR.MLR.BF.FspiB (Fucus spiralis on full salinity exposed to moderately exposed upper eulittoral rock)
LR.FLR.Rkp.G (Green seaweeds (Entomorpha spp. and Cladophora spp.) in shallow upper shore rock pools)
LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools)





The rocky shore. Habitat classification:  LR.MCR.BF (Barnacles and fucoids on moderately exposed shores) and LR.FLR.Rkp (Rock pools).
Shallow pools of the upper shore pools are dominated by ephemeral green algae that characterizes the biotope LR.FLR.Rkp.G (Green seaweeds (Entomorpha spp. and Cladophora spp.) in shallow upper shore rock pools) that occurs within the broader biotope complex LR.FLR.Rkp (Rockpools).

Channel wrack (Pelvetia canaliculata) on the upper shore. Pelvetia canaliculata characterizes the biotope LR.LMR.BF.PelB (Pelvetia canaliculata and barnacles on moderately exposed shores) that occurs within the broader biotope complex of LR.MLR.BF (Barnacles and fucoids on moderately exposed shores). The band of channel wrack delimits the upper extent of the biotope complex.
Small periwinkles (Melarhaphe neritoides) seek shelter within a tiny pit of the bed rock on the upper shore. Habitat classification:  LR.LMR.BF.PelB (Pelvetia canaliculata and barnacles on moderately exposed shores).

Spiral wrack (Fucus spiralis) and barnacles exhibit a patch work distribution within which rock pools occur. Fucus spiralis characterizes the biotope LR.MLR.BF.FspiB (Fucus spiralis on full salinity exposed to moderately exposed upper eulittoral rock) that occurs within the broader biotope complex of LR.MLR.BF (Barnacles and fucoids on moderately exposed shores).
Spiral wrack (Fucus spiralis) in its reproductive phase with swollen ends to the frond known as receptacles that contain the conceptacles from which gametes are released. Habitat classification: LR.MLR.BF.FspiB (Fucus spiralis on full salinity exposed to moderately exposed upper eulittoral rock).
Spiral wrack (Fucus spiralis) and barnacles exhibit a patch work like distribution. Habitat classification: Habitat classification: LR.MLR.BF.FspiB (Fucus spiralis on full salinity exposed to moderately exposed upper eulittoral rock).
A dog whelk (Nucella lapillus) on the mid shore. Habitat classification: LR.MLR.BF.FspiB (Fucus spiralis on full salinity exposed to moderately exposed upper eulittoral rock).
Coralline crust dominates this small rock pool that acts as a refuge for a multiple of fauna, including anemones, algae, mussels and periwinkles. Coralline crusts characterizes the biotope LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools) that occurs within the broader biotope complex LR.FLR.Rkp (Rock pools).

Coral weed (Corallina officinalis) grows as an epiphyte of the coralline crust and periwinkles seek refuge within the small pool. Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools).

The common blue mussel (Mytilus edulis) also occurs within the small pool. Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools).

A coralline crust dominated rock pool with the coral weed (Corallina officinalis), Limpets, Breadcrumb sponge (Halichondria (Halichondria) panacea), ephemeral green algae and a brown seaweed. Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools).
In some cases coralline pools can become overwhelmed by the seasonal growth in ephemeral green algae.  Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools).
Coralline pools situated closer to the low tide mark are richer in seaweed species.  Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools).
Anemones in a coralline rock pool.  Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools).
Beadlet anemones (Actinia equina) can be found amongst the rock pools. Habitat classification: LR.FLR.Rkp (Rock pools).

Rock pools further down the shore are home to Snake locks anemones (Anemonia viridis). Habitat classification: LR.FLR.Rkp (Rock pools).


A hermit crab (Paguroidea) in a rock pool. Habitat classification: LR.FLR.Rkp (Rock pools).


Large rock pools occur on the shore. Habitat classification: LR.FLR.Rkp (Rock pools).

The boulders within these larger pool are encrusted in coralline crusts, their vertical extend marking the lowest water levels experienced by the rock pool. Barnacles, limpets (Patella vulgata), snakelocks anemones (Anemonia viridis) and a variety of seaweeds also occur. Habitat classification: LR.FLR.Rkp (Rock pools).