Rockpooling destination: Revisit Land's End peninsular: Scour tolerant and robust fucoid/red seaweed habitats

Steep cliffs surround the bay, the lower craggy edges covered in lichens. The cliff bases and steeper bedrock transition between the lichen and barnacle communities with limpets, periwinkles and whelks. Boulders and bedrock of the mid and lower shore host a similar barnacle community plus a variety of seaweeds, including where sand scour is event, ephemeral seaweeds. Rockpools occur throughout the shore, and a river flows downs from the cliffs.

The bay experiences a dynamic regime, alternating between periods of erosion and deposition. The underlying substrate is boulders and bedrock, however, variable amounts of sand may be deposited on top, sourced from the sand bar situated offshore. The communities encountered reflect the alternation between these regimes.


The shore alternates between periods of deposition (sandy)  and erosion (stony).

April 2015

September 2013                    January 2014
The overlaying sand has been eroded to reveal the boulders beneath.

At the time of visitation the cove was comprised of boulders and bedrock with an occasional thin veneer of sand.

Habitat classification:

Substrate	LR (Littoral rock)
Habitat	LR.HLR (High energy littoral rock)	LR.MLR (Moderate energy littoral rock)		LR.FLR (Features of ilttoral rock)
Biotope complex	LR.  HLR.MusB (Mussels and/or barnacles on high energy littoral rock)	LR.MLR.BF (Barnacles and fucoids on moderately exposed shores)		LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock).	LR.FLR.Rkp (Rockpools)		LR.FLR.Eph (Ephemeral green or red seaweed communities		LR.FLR.CvoV (Littoral caves and overhangs).
Biotope		LR.MLR.BF.Fser (Fucus serratus on   moderately exposed eulittoral rock)	LR.MLR.BF.Rho (Rhodothamniella floridula on sand scoured lower eulittoral rock)	LR.FLR.Lic.Ver (Verrucaria Maura on littoral fringe rock)	LR.FLR.Rkp.Cor (Coralline crust-dominated shallow eulittoral rockpools)	LR.FLR.Rckp.SwSed (Seaweeds in sediment- floored eulittoral rockpools).	LR.FLR.Eph (Ephermeral green or red   seaweeds (Fresh water or sand influenced)	LR.FLR.Eph.EntPor (Porphyra purpurea and Entomorpha spp. on sand scoured mid to  lower eulittoral rock)
Sub Biotope		LR.MLR.BF.Fser.R (Fucus serratus and red seaweeds on moderately exposed lower eulittoral rock)			LR.FLR.Rkp.Cor.Cor (Corallina officinalis and coralline crusts in shallow eulittoral rockpools)

Below are images of organisms you may encounter whilst rockpooling among the lower shore habitats:

The influences of subtidal sand scour increases on the lower shore, influencing the species found. Sand scour tolerant  seaweeds flourish, including the red seaweed, sand binder (Rhodothamniella floridula) and the ephemeral green Cladophora spp.

Sand binder (Rhodothamniella floridula) can attain high abundance on the shore. Habitat classification: LR.MLR.BF.Rho (Rhodothamniella floridula on sand scoured lower eulittoral rock)

Among the sandbinder covered rock are rockpools filled with sand . These sediment filled rockpools support a variety of  red and ephemeral green seaweeds  including, Corallina officinalis, Ahnfeltia plicata and Lomentaria articulata.  LR.FLR.Rkp.SwSed (Seaweeds in sediment-floored eulittoral rockpools) EUNIS:A1.413.

Rhodophtya within a sand filled rockpool of the lower shore.

Rhodophtya within a sand filled rockpool of the lower shore.

Rhodophtya (Polyides rotundus) within a sand filled rockpool of the lower shore.

Ulva spp

A sea hare (Aplysiomorpha) and anemone within a sand filled rockpool of the lower shore.

The green seaweed, Bryopsis spp

A juvenile crab

Anemonia viridis

The ephemeral green seaweed, Cladophora rupestris.

Seaweed abundance within the sediment filled rockpools, especially that of ephemeral greens is not as extensive as observed in October, 2014. (See blog post  http://thesaltyscavenger.blogspot.co.uk/2015/03/rockpooling-destination-revisit-of.html )

Where sand scour is reduced  serrated wrack and red seaweeds increase in abundance to form patches among the sand binder. Habitat classification: LR.MLR.BF.Fser.R (Fucus serratus and red seaweeds on moderately exposed lower eulittoral rock) and LR.MLR.BF.Rho (Rhodothamniella floridula on sand scoured lower eulittoral rock.

 The seaweeds of  LR.MLR.BF.Fser.R (Fucus serratus and red seaweeds on moderately exposed lower eulittoral rock)  include Lomentaria articulata, Mastocarpus stellatus, Fucus serratus, Chondrus crispus, Rhodothamniella floridula and Osmundea Spp.

Grey topshell (Gibbula cineraria)

Eventually Fucus cover gives way to robust reds and Himanthalia elongata. Habitat classification: LR.HLR.FR (Robust fucoids and/or red seaweed communities) EUNIS: A1.12.

Corallina officinalis forms a turf on the bedrock with robust reds, Himanthalia elongata and Laminaria spp.

Corallina officinalis forms a turf on the bedrock.

Mastrocarpus stellatus,  Rhodothamniella floridula, Laminaria spp and Himnathlia elongata.

Osmundea spp, Corallina spp  and Himnathlia elongata.

Rhodophyta

Rhodophyta

Bifurcaria bifurcata

Chondracanthus acicularis

A turf of robust reds, dominated by Mastrocarpus stellatus,  Laminaria spp and Himnathlia elongata.

Himnathlia elongata.

Edible crab (Cancer pagurus)

Sea caves on the shore provide shade allowing species who are more sensitive to sunlight  to extend their occurrence beyond that of the rockpools. Habitat classification: LR.FLR.CvoV (Littoral caves and overhangs) EUNIS: A1.44.

Corallinaceae crusts occur within and extend beyond the rockpools of the cave entrance due to the shade provided by the overhanging cliff.

Cladophora spp and Coralinaceae crusts live in the shaded entrance of the sea cave.

Corallinaceae crusts occur within a rockpool of the cave cliff edge.

Rockpooling destination: Revisit Penberth April, 2015

The shore comprises a narrow cove with boulders lining either side of a slipway. There is a river that forms a small waterfall on the upper shore before flowing beneath the boulders to the sea.

The cove experiences high wave exposure and is characterized by an extended splash zone with lichens and periwinkles. Barnacles characterise the mid and lower shore,  with an increased abundance of barnacles, limpets and robust seaweeds towards the low water mark. There are relatively small gravel filled rockpools beneath the boulders and coralline rockpools at the cliff edges.

The tide was lower than during previous visits allowing  a greater variety of lower shore red seaweeds to be photographed. However, time prevented me from looking at the fresh water influenced habitats of the upper shore which, I have photographed previously. 
See blog post:  http://thesaltyscavenger.blogspot.co.uk/2013/11/rock-pooling-destination-penberth.html

Below are images of organisms you may encounter whilst rockpooling in these habitats:

The rocky shore is comprised of boulders and a slip way. A variety of Yellow and grey lichens characterise the supralittoral.  Habitat classification: LR.FLR.Lic (Lichens on supralittoral and littoral fringe rock) EUNIS:B3.111

Blackshields

Plants also occur between the boulders in the supralittoral.

Black tar lichen (Verrucaria maura) markes the transitions from the supralittoral to the littoral fringe habitats. Habitat classification: 

LR.FLR.Lic.Ver (Verrucaria Maura on littoral fringe rock) EUNIS: B3.113

Sparse barnacles occur within the V.maura biotope.

Limpets (Patella vulgata), Periwinkles (Littorina spp.) and sparse barnacles.

Littorina compressa nigrolineata 

Barnacles and periwinkle

Small periwinkles (Melarhaphe neritoides)

Small red mites scurry across the rocks.

An ant on the upper shore. There are a variety of terrestrial insects that you can come across on the shore, especially during the summer months. However, this component of the intertidal ecology is often over looked.

An ant on the top of a coralline rock pool.

Snakelocks anemone (Anemonia viridis) in a coralline rockpool. The rockpools of the shore are confined to the bedrock of the cliff edges, and mainly comprise narrow stretches of water. Habitat classification: LR.FLR.Rkp.Cor (Coralline crust-dominated shallow eulittoral rockpools) EUNIS A1.411

Snakelocks anemone (Anemonia viridis)

China limpets (Patella ulyssiponensis) within a coralline rockpool. 

Thick topshell (Osilinus lineatus)

The lichen, Lichina pygmaea occurs in patches among the barnacles communities of the upper shore. Habitat classification: LR.HLR. MusB (Mussel and/or barnacle communities), EUNIS: A1.11.

The boulders of the mid shore support a community of barnacles, limpets, dog whelks and where conditions allow seaweeds. Habitat classification: LR.HLR. MusB (Mussel and/or barnacle communities), EUNIS: A1.11.

Between the boulders beadlet anemones (Actina equina) and small individual seaweeds can also be found.

Spiral wrack  (Fucus spiralis)

Several of the boulders have patches of a dark green lichen/algae?

Dog whelks (Nucella lapillus)

On the lower shore the density of barnacles increases and Patella depressa is found.

Barnacles on the lower shore.

Volcano barnacles (Balanus perforatus) beneath a boulder overhang if the lower shore.

Grey topshell (Gibbul cineraria) on the lower shore.

A low turf of coralline algae.

As the lower shore is reached there is a proliferation of wracks and red seaweeds. Habitat classification: LR.HLR.FR.Him (Himanthalia elongata and red seaweeds on exposed to moderately exposed lower eulittoral rock).

Osmundea spp and short Corallina spp turfs

Throng weed (Himanthalia elongata) over grows a turf if red seaweeds at the low tide mark.

A variety of red seaweeds co occur in close proximity.

Mastrocarpus stellatus grows among the stypes of Himanthalia elongata.

Chondrus crispus and Osmundea spp

Lomentaria articulata

Young fucoids, greens and plumose reds drape a boulder at the low tide mark.

A seal sleeps whilst I rockpool around the shore.