Rockpooling Destination: Revisit to Lands End Peninsula Sept 2015

As seen in the previous post the bay has experienced some recent changes in deposition and erosion, resulting in the formation of a strandline and winnowing of finer material from the uppershore cobble beach. However, these are not the only changes to have occurred as this post will reveal...

As seen in the previous post a strandline has formed on the upper extent of the cobble beach. The newly formed strandline is important as it provide a resource for food and shelter, on an otherwise barren upper cobble and boulder beach.

This photograph taken in June, 2015 shows the absence of a strandline on this section of the shore. See post http://thesaltyscavenger.blogspot.co.uk/2015/08/rockpooling-destination-revisit.html 

This photograph taken in June, 2015 shows much of the upper shore bedrock and boulders covered by seaweed. See post http://thesaltyscavenger.blogspot.co.uk/2015/08/rockpooling-destination-revisit.html

However, by September, 2015 the percentage cover of seaweed on upper shore boulders and bedrock has reduced. 

Bedrock that was covered in ephemeral green seaweeds are now bare, whilst the Fucus sp is reduced to stumps.

There is a distinct lack of 'green' in this photograph compared to the photograph below that was taken in June, 2015.

Fucus sp cover the boulders, whist ephemeral green seaweed lace the diluted and sand scoured rockpools. June, 2015. See post http://thesaltyscavenger.blogspot.co.uk/2015/08/rockpooling-destination-revisit.html

What could have caused this change? Abrasion from the winnowed sediment? Seasonal die back or grazing? Since June there has been an increase in limpet abundance, c. Could their grazing be accountable?

Limpet density is higher than in June, could it be that individuals moved with the changing season. Seasonal migrations are noted in limpet species of British species (http://www.marlin.ac.uk/biotic/browse.php?sp=4220) or, were  the limpets swept in with  the fronds of the strandline , as noted for limpets in Advances in Marine Biology vol 16 or, maybe population abundance has peaked as a feature of the limpet life histories?

Topshell density had also increased behind the stack.

There were no signs of the tube dwelling amphipods among the seaweeds of the sediment filled pools, only the cases of thier tubes remained.

In June many amphipods were observed occupying tubes which were in  turn enveloped among the green seaweed. See post http://thesaltyscavenger.blogspot.co.uk/2015/08/rockpooling-destination-revisit.html

All other seaweeds except the fucoids exhibited no or little seasonal die back at this time and the remaining habitats remained largely unchanged since June, 2015.

Tadpoles on the shore! Near Kilchoan, Scotland, May 2015

Rockpools located within the transitional zone between the supralittoral and angiosperm dominated terrestrial habitats are often relatively barren of life, but on this occasion the rockpools were filled with tadpoles!

Rockpools located within the transitional zone between the supralittoral and angiosperm dominated terrestrial habitats.

Tadpoles within the rockpool.

Rockpooling Destination: Kilchoan, Scotland, May 2015

The cobble shore at Kilchoan may appear calm, but the shores' sloping angle and step, indicates that it experiences periods of high wave exposure. 

The shore comprises a sloping cobble beach with a stepped profile and strandlines. Fauna are relatively sparse among the cobbles, with increased diversity within the decomposing seaweed of the strandline. Habitat classification: LR.HR (High energy littoral rock) EUNIS: A1.1  LS.Lsa.St (Strandline) EUNIS: A2.21.

The most striking fauna of the cobbles, are the red mites that scurry across the shore.

Rockpooling Destination: Great Yarmouth, December 2014

During the winter months a strandline forms along many of the sandy shingle shores of Norfolk.

Many different things can be found washed up among the strandline including the remains of seaweeds, sponges, hornwrack, hydrozoans, crabs and shells.

The shore at Great Yarmouth is comprised of sand and shingle, a succession of strand lines mark the varying tide heights.Habitat classification: LS.LSa.St (Strandline) and LS.LSa (Littoral sand).

A tree weed washed up on the shore.

A tree weed washed up on the shore.



A tree weed washed up on the shore.



Osmundea sp growing as an epiphyte of Egg wrack (Ascophyllim nodosum).



Osmundea sp growing as an epiphyte of Egg wrack.

Osmundea sp growing as an epiphyte of Egg wrack.

Crinkle edge weed.

A small spotted catshark (Scyliorhinus canicula) egg case.

Rockpooling Destination: Hemsby, December 2014

Erosion during a winter storm has caused a 'step' in the beach profile and removed the finer sediments whilst leaving the coarser sediments (pebbles and cobbles).

A 'stepped' profile caused by wave erosion. Habitat classification: LS.Sa (Littoral sand) and LS.LCS (Littoral coarse sediments)

The shore has a relatively shallow profile which is dissected by a step caused by wave erosion.



The sandy shore a month before with a relatively shallow profile compared to that of the 'stepped' profile caused by the erosional processes of the storm. Habitat classification: LS.LSa.St (Strandline) and LS.LSa (Littoral sand).



Rockpooling destination: Hemsby, November 2014

During the month of November, washed up red seaweeds dominate the strandline at Hemsby, Norolk.
  

The sandy shore with a strand line dominated by red seaweeds. Habitat classification: LS.LSa.St (Strandline), LS.LSa (Littoral sand) to LS.LCS (Littoral coarse sediments).

The strandline is comprised of a variety of red seaweeds, the bryozoan, hornwrack (Flustra foliacea) and empty razor shells.



A sponge (Porifera) washed up in the strandline.

Clawed Fork Weed (Furcellaria lumbricalis) washed up in the strandline.

Clawed Fork Weed (Furcellaria lumbricalis).

Epiphytic red seaweed on Clawed Fork Weed (Furcellaria lumbricalis).

A red tree weed.

A red tree weed.

Rockpooling Destination: Hemsby, January 2015

A strandline dominated by hornwrack still occurs on the shore but now several new things are beginning to be washed up in the strandline too. 

The most interesting are the mermaids' purses; months before skates, rays and catfish (formally dogfish) laid their egg cases among the cobbles and bryozoans and within these egg cases the embryos developed into miniature adults. As they became too large for their egg cases they broke free and the discarded egg cases drifted with the waves and currents until finally, they were washed up on the shore.

If you find a mermaids' purse why not report your sighting to the shark trust great egg case hunt?. You can find out more about submitting sightings and about rays and sharks at 
http://www.sharktrust.org/en/great_eggcase_hunt

The sandy shore with a strandline dominated by the remains of the bryozoan, hornwrack (Flustra foliacea). Habitat classification: LS.LSa.St (Strandline) and LS.LSa (Littoral sand).

The sandy shore with a strandline dominated by the remains of the bryozoan, hornwrack (Flustra foliacea)

A small spotted catshark (Scyliorhinus canicula) egg case.

A Thornback (Raja clavata) egg case

A spotted ray  (Raja montagui) egg case.

This was one of two, grey seal pups washed up on the shore that day. 

Rockpooling destination: Walls, Shetland September 2014

The low cliffs around Walls incline steeply toward the sea and are covered by lichens, in this sheltered inlet a distinct transition has formed between the yellow and grey lichens of the supralittoral and the tar lichen of the littoral fringe. Below the lichens are bands of barnacles and then fucoids.

Habitat classification:

Biotope complex	LR.MLR.BF (Barnacles and fucoids on moderately exposed shores)	LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock).
Biotope	LR.MLR.BF.FspiB (Fucus spiralis on full salinity exposed to moderately exposed upper eulittoral rock)	LR.FLR.Lic.Ver (Verrucaria maura on littoral fringe rock)	LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock)

The low cliffs slope steeply and are characterized by lichens. Habitat classification: LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock).

Yellow and grey lichens occur with sea pinks in the supra littoral zone, below which tar lichen forms a black covering over the rocks. Habitat classification LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock) and  LR.FLR.Lic.Ver (Verrucaria maura on littoral fringe rock).

Sea ivory (Verrucaria maura), grey, orange and brown lichens are commonly encountered within the habitat yellow and grey lichens on supralittoral rock.

Yellow and grey lichens occur in the supra littoral zone, below which tar lichen forms a black covering over the rocks in the littoral fringe with barnacles and fucoids below . 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.MLR.BF (Barnacles and fucoids on moderately exposed shores).

Rockpooling destination: Unst, Shetland September 2014

The rocky shore comprises steeply shelving bedrock with crevices and small rock pools.

Tar lichen occurs in the littoral fringe and extends as patches into the upper shore (supralittoral). The upper and mid shore are charecterised by barnacles, periwinkles and limpets with the addition of mussels and dog whelks in the mid shore; ephemeral red and green seaweeds occur across the mid and lower shore. The abundance of barnacles and clumps of large mussels in the mid shore and presence of rock pools is characteristic of the habitats LR.MLR.BF (barnacles and fucoids on moderately exposed shores) and LR.FLR.Rkp (rock pools).

Habitat classification:

Biotope complex	LR.MLR.BF (Barnacles and fucoids on moderately exposed shores)			LR.FLR.Rkp (Rockpools)
Biotope				LR.FLR.Rkp.Cor (Corallina officinalis, coralline crusts and brown seaweeds in shallow eulittoral rockpools)

Below are images of the organisms you may encounter within this habitat:

The rocky shore comprises steeply sloping bed rock with crevices and small coralline rock pools.  The upper shore is charecterised by barnacles and periwinkles, the mid shore by barnacles, periwinkles, limpets, mussels, dog whelks and red seaweeds, whilst the lower shore is charecterised by ephemeral green and red seaweeds.

Barnacles and small periwinkles ( Melarhaphe neritoides) of the upper shore.

Barnacles density increases as you go down the shore.
Barnacles, mussels (Mytilus edulis) and small periwinkles ( Melarhaphe neritoides) of the mid shore. 

Dog whelks (Nucella lapillus), barnacles and M. edulis on the mid shore.

Old N. lapillus egg capsules.

M. edulis overgrown by red seaweeds.

M. edulis covered by Porphyra sp

Ephemeral greens (Ulva sp) and red (Porphyra sp) seaweeds on the lower shore.

Ephemeral greens (Ulva sp) and red (Porphyra sp) seaweeds on the lower shore.

Ephemeral greens (Ulva sp) and red (Porphyra sp) seaweeds on the lower shore.

Mastocarpus stellatus on lower shore.