Revisit: Land's End Peninsular September 2015

The bay experiences a dynamic regime, alternating between periods of erosion (stony) and deposition (sandy).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.

Please see previous blog posts:
http://www.thesaltyscavenger.blogspot.co.uk/2015/08/rockpooling-destination-revisit.html
http://thesaltyscavenger.blogspot.nl/2015/07/rockpooling-destination-revisit-lands.html
http://thesaltyscavenger.blogspot.nl/2014/05/revisit-lands-end-peninsular-april-2014.html
http://thesaltyscavenger.blogspot.nl/2014/02/rockpooling-destination-lands-end.html

On my most recent visit in September, 2015 the shore was starting to show the signs of Autumn with winnowing of finer sediments from the upper shore and an increased strandine reaching across the entire cobble and boulder beach. Some seaweeds also showed signs of seasonal die back.

The rocky shore during the current visit in September, 2015 shows little variation from June, 2015 except in the upper shore, where there has been erosion and winnowing of finer sediments and the formation on a strandline across the entire cobble and boulder beach.

The rocky shore in June 2015, does not support a strandline across the entire cobble and boulder beach.

The strandline that filled the cave in June, 2015 is no longer visible, only a wedge of seaweed behind the boulder can be seen. However, the height of the sand in relation to the boulder suggests that there has been increased deposition of sand within the cave since June and it may be that this sand has covered the strandline that was present or, the seaweed has now been washed up to form the strandline across the cobble and boulder beach?

The strandline present within the cave in June 2015. 

Again the strandline present on this section of the shore in June, 2015 has now gone and the finer sediments present in June and April, 2015 have been winnowed from between the cobbles and boulders.

Seaweed in June, 2015 had been washed up among the boulders of this part of the shore. 

This photograph taken in April 2015, shows the finer material that once occurred on this part of the shore and has now been winnowed away.

Fucoids begin to show seasonal die back. The lost fronds contribute to the strand line.

Land’s End Peninsula, England, August 2012

Rock pooling destination: Land’s End Peninsula, England, 2012

The bay experiences a dynamic regime, alternating between periods of erosion and deposition. The underlying substrate is boulders, 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.

At the time of visitation the beach was mainly sand with boulders exposed in the region of the river and amongst out cropping bedrock in the mid to lower shore.

The highest abundances of organism are encountered on the most persistent substrate, which is the hard substrate that does not experience sand deposition, mainly the steep sloping bedrock that forms the base of the cliff and represents the upper shore. This environment is dominated by barnacles, with limpets, periwinkles, whelks and the coral weed Corallina officnalis all of which are characteristic of a high energy regime environment.

The lower shore is more characteristic of a moderate energy regime with focuids and the red seaweed Mastocarpus stellatus covering boulders and bedrock, additionally Rhodothamniella floridula is present where sand scours the boulders.

The hard substrate of the upper shore can broadly be characterised under the habitat classification: LR.HLR.MusB (Mussel and/or barnacle communities) and the hard substrate of the mid and lower shore can be broadly characterised under the habitat classification: LR.MLR.BF (Barnacles and fucoids on moderately exposed shores); whilst the sand can be characterised as LS.LSa (Sublittoral sand).

Below are photographs of some of the organisms

encountered whilst rock pooling in this habitat.

Fresh water influx to the shore.

The sediment type of the beach varies temporally between sand and boulders; the river
has washed away the superficial layer of sand to reveal the boulders that occur across the bay beneath the sand.

Barnacles and Lipets (Patella vulgata).
Habitat classification: LR.HLR.MusB (Mussel and/or barnacle communities)

Dog whelk (Nucella lapillus).

Mastocarpus stellatus

Coralline algae are confined to the crevise where water seeps from a rock pool above.

Limpets (Patella vulgata) attach themselves to a boulder that has been covered by sand.

Strand line of kelp and Ulva spp.

Barnacles and Limpets (Patella vulgata).



Serrated wrack (Fucus serratus). Habitat classification: LR.MLR.BF
(Barnacles and fucoids on moderately exposed shores).

Serrated wrack (Fucus serratus).

Mastrocarpus stellatus and sand binder (Rhodothamniella floridula).
Biotope classification: LR.MLR.BF.Rho (Rhodothamniella floridula on sand scoured
lower eulittoral rock).

Mastrocarpus stellatus and serrated wrack (Fucus serratus).

Codium spp in shallow sand pool of the lower shore.

Beadlet anemone (Actinia equina).



Ulva spp and Cladophora in a sand scoured pool of the lower shore.
These species are able to grow quickly and can persist during the alternating regimes.



Ulva spp and Cladophora in a sand scoured pool of the lower shore.

Grey Atlantic Seals frequent the bay.