Wednesday 20 August 2014

Rockpooling destination: Mousehole May, 2014

The shore comprises bedrock with gullies, crevices and rockpools. The variability in the bedrock topography results in a patchy distribution of habitats. Ephemeral green seaweeds characterise many of the upper and lower shore rockpools, while the mid shore is characterised by coralline seaweeds. The only seaweed to occur outside the rockpools is a band of channel wrack in the upper-mid shore, elsewhere the rock is bare. Gastropods occur across the shore.

Habitat classification:

Substrate
LR (Littoral rock)
Habitat
LR.MLR (Moderate energy littoral rock)
LR.FLR (Features of ilttoral rock)
Biotope complex
LR.MLR.BF (Barnacles and fucoids on moderately exposed shores)
LR.FLR.Rkp (Rockpools)
Biotope
LR.LMR.BF       (Pelvetia canaliculata and barnacles on moderately exposed shores)
LR.FLR.Rkp.Cor (Corallina officinalis, coralline crusts and brown seaweeds in shallow eulittoral rockpools)
LR.FLR.Rkp.G        (Green seaweeds (Entomorpha spp. and Cladophora spp.) in shallow upper shore rock pools)



Below are images of organisms you may encounter whilst rockpooling in this habitat:

The rocky shore comprises bedrock with gullies, crevices and rockpools. Habitat classification: LR.ML (Moderate energy littoral rock), LR.FLR.Lic (Lichens on supralittoral and littoral fringe rock) and LR.FLR.Rkp (Rockpools).

A rock pipit forages stands amongst Lichens of the splash zone. Habitat classification: LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock).

The rockpools of the upper shore experience fluctuations in salinity and temperature which restricts gastropod density, thus allowing the prolific growth of ephemeral green seaweeds: Habitat classification: LR.FLR.Rkp.G  (Green seaweeds (Entomorpha spp. and Cladophora spp.) in shallow upper shore rock pools.

Thick topshells (Osilinus lineatus) aggregate above the rockpools of the upper shore.
A lichen, probably Ochrolechia parella

Due to the topographic variability of the bedrock the distribution of lichens is patchy; with yellow and green lichens simultaneously above and below tar lichen (Verrucaria Maura). However the proile of the shore reveals that the Verrucaria Maura does indeed occur at a lower altitude, and that its the bedrock that dips and then rises again. Habitat classification: LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock) and LR.FLR.Lic.Ver (Verrucaria Maura on littoral fringe rock) both of which occur within the broader habitat LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock).



As you go further down the shore ephemeral green seaweed decreases in abundance and corallinacea crusts begin to cover the rockpool floor. Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools).

A white blaze marks a previous lower water mark within the rockpool when the corallinacea crust became exposed and bleached by the sun.

Ephemeral green seaweed (Ulva sp) 

Channel wrack (Pelvetia canaliculata) and sparse barnacles. Habitat classification: LR.LMR.BF.PelB (Pelvetia canaliculata and barnacles on moderately exposed shores).
Channel wrack  (Pelvetia canaliculata) occurs as a band across a certain height on the shore.
Channel wrack (Pelvetia canaliculata) in its reproductive phase with swollen receptacles at the end of their fronds.
Barnacles and Small periwinkles (Melarhaphe neritoides) which seek refuge within the dead barnacle tests occur on the upper shore.

A flat periwinkle (Gibbula umbilicus) within a coralline rockpool.


A rockpool on the lower shore with ephemeral green seaweed (Ulva sp) and edible periwinkles (Littorina littorea). Habitat classification: LR.FLR.Rkp (Rockpools)
An edible periwinkle (Littorina littorea)
An edible periwinkle (Littorina littorea) and thick topshell (Osilinus lineatus).


Dead bryozoan washed up on the shore.

Dead bryozoan washed up on the shore.

The bedrock of the lower shore is bare with ephemeral green seaweeds restricted to those crevices or those areas that will become rockpools as the tide reseeds

Monday 18 August 2014

Rockpooling destination: Great Bay, St. Martins April 2014

The rocky shore comprises a bedrock outcrop with crevices and rockpools. The shore is charectersied by a patch work of barnacles and fucoid seaweeds, with fucoid density increasing as the low tide mark is approached. Coralline rockpools occur throughout the shore with species diversity increasing as you go down the shore.

Habitat classification:
Substrate
LR (Littoral rock)
Habitat
LR.MLR (Moderate energy littoral rock)
LR.FLR (Features of ilttoral rock)
Biotope complex
LR.MLR.BF (Barnacles and fucoids on moderately exposed shores)
LR.FLR.Rkp (Rockpools)
Biotope
LR.MLR.BF.FspiB (Fucus spiralis on full salinity exposed to moderately exposed upper eulittoral rock)
LR.MLR.BF.Fser (Fucus serratus on moderately exposed eulittoral rock)

LR.FLR.Rkp.Cor (Corallina officinalis, coralline crusts and brown seaweeds in shallow eulittoral rockpools)
Sub Biotope



 LR.FLR.Rkp.Cor.Bif (Bifurcaria bifurcate in shallow eulittoral rockpools)


Below are images of organisms that you may encounter whilst rockpooling in this habitat:


The rockyshore comprises bedrock that gently slopes toward the low water mark amongst which are crevices and rockpools. Fucoids and barnacles form a mosaic across the shore. Habitat classification: LR.MLR.BF (Barnacles and fucoids on moderately exposed shores).


Barnacles on the upper shore.

Small periwinkles (Melarhaphe neritoides) use the dead test of a barnacle as a refuge from the desiccating effects of the sun and wind.

Lichina pygmaea
Spiral wrack (Fucus spiralis), barnacles, limpets (Patella sp.), beadlet anemones (Actinia equina), dog whelk (Nucella lapillus) and Lichina pygmaea on the upper shore. Habitat classification: LR.MLR.BF.FspiB (Fucus spiralis on full salinity exposed to moderately exposed upper eulittoral rock).

Limpets (Patella sp), Osmoundea sp, Spiral wrack (Fucus spiralis) and the dead tests of barnacles.

A coralline rockpool surrounded by serrated wrack (Fucus serratus) and barnacles. Habitat classification: LR.FLR.Rkp.Cor (Corallina officinalis, coralline crusts and brown seaweeds in shallow eulittoral rockpools) and LR.MLR.BF.Fser (Fucus serratus on moderately exposed eulittoral rock.

A coralline rockpool with Corallina officinalis and other seaweeds. 

A coralline pool with Corallina officinalis and pink plates (Mesophyllum lichenoides). 


A coralline rockpool on the lower shore with abundant ephemeral green algae growth and dominated by brown forking weed (Bifurcaria bifurcata). Habitat classification: LR.FLR.Rkp.Cor.Bif (Bifurcaria bifurcata in shallow eulittoral rockpools)

A red seaweed within a coralline pool

A red seaweed within a coralline pool

A red seaweed within a coralline pool



Thursday 14 August 2014

Rockpooling destination: Perpitch, St. Martins, April 2014

The rockyshore comprises boulders with fucoids in the mid and lower shore that give way to a turf of reds and ephemeral green seaweeds, and then finally thong weed.

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


Below are images of organisms you may see whilst rockpooling in this habitat:


The rockyshore comprises boulders with fucoids in the mid and lower shore that give way to a turf of reds and ephemeral green seaweeds, and then finally thong weed. Habitat classification: LR.MLR.BF (Barnacles and fucoids on moderately exposed shores)


Boulders covered by common limpets (Patella vulgata) and thick topshells (Osilinus lineatus) with patches of fucoids. Habitat classification: LR.MLR.BF (Barnacles and fucoids on moderately exposed shores)

Thick topshells (Osilinus lineatus).

Serrated wrack  (Fucus serratus) occurs on the lower shore along with a variety of red seaweeds including, Mastocarpus stellatus and Lomentaria articulata.

Chondus crispus
Lomentaria articulata
On the lowest section of the shore brown forking weed (Bifurcaria bifurcata) and reds including Osmoumdea sp characterise the habitat.

Osmoumdea sp

Creephorn weed (Chondracanthus acicularis) and Osmundea sp

Creephorn weed (Chondracanthus acicularis)


Cladophora rupestris

A red seaweed on the lower shore



A red seaweed growing on a limpet

A red seaweed growing on a limpet

Tuesday 12 August 2014

Rockpooling destination: Porth seal, St. Martins April 2014

The shore comprises bedrock and boulders with swathes of sand on the upper shore. Rock pools and channels occur throughout the central section of the bedrock supporting a variety of marine life.

The distribution of habitats across the bay is patchy. Lichens occur at the top of the shore below which fucoids form a mosaic with barnacles. Rockpools occur across the shore and increase with species diversity toward the low water mark.

The rock pools vary with those in the upper shore characterized by the green seaweeds Cladophora and Ulva spp; whilst mid shore pools are dominated by encrusting coralline algae and a variety of red and brown seaweeds; further down the shore brown seaweeds, such as Bifurcaria bifurcata and Himanthalia elongata, become more prolific within the coralline pools with red seaweeds occupying the understory. Above the pools is a mosaic of fucoids, osmoundea, grazing molluscs and barnacles.

Spring storms had washed seaweed up onto the shore where it formed successive strandlines and filled many of the higher shore pools. The presence of the decomposing seaweed in the pools caused the water to become de-oxygenation and stagnant. In comparison to April 2013 there was less washed up seaweed and sand in the rock pools.

The shore comes under the broad habitats (LS.Lsa) Littoral sand, LR.FLR.Rkp (Rockpools)and LR.MLR.BF (Barnacles and fucoids on moderately exposed shores) with a number of sub variants of the latter.

Habitat classification:




Substrate
LR (Littoral rock)
Habitat
LR.MLR (Moderate energy littoral rock)
LR.FLR (Features of ilttoral rock)
Biotope complex
LR.MLR.BF (Barnacles and fucoids on moderately exposed shores)
LR.FLR.Rkp (Rockpools)
LR.FLR.Eph (Ephemeral green or red seaweed communities
Biotope
LR.MLR.BF.FspiB (Fucus spiralis on full salinity exposed to moderately exposed upper eulittoral rock)
LR.MLR.BF.Fser (Fucus serratus on moderately exposed eulittoral rock)
LR.LMR.BF       (Pelvetia canaliculata and barnacles on moderately exposed shores)
LR.MLR.BF.Rho (Rhodothamniella floridula on sand scoured lower eulittoral rock)
LR.FLR.Rkp.Cor (Corallina officinalis, coralline crusts and brown seaweeds in shallow eulittoral rockpools)
 LR.FLR.Rckp.SwSed (Seaweeds in sediment- floored eulittoral rockpools).
LR.FLR.Rkp.G        (Green seaweeds (Entomorpha spp. and Cladophora spp.) in shallow upper shore rock pools)
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)
 LR.FLR.Rkp.Cor.Bif (Bifurcaria bifurcate in shallow eulittoral rockpools)



Below are images of organisms you may encounter whilst rock pooling in this habitat:


The bay comprises sandy patches in the upper shore with bedrock and boulders that shallowly descend to the low water mark with rockpools throughout.  Habitat classification: LS.LSa (Littoral sand), LR.MLR.BF (Barnacles and fucoids on moderately exposed shores) and LR.FLR.Rkp (Rockpools).

Channel wrack (Pelvetia canaliculata) and tar lichen (Verrucaria maura) occur at the top of the shore on the right hand side of the bay. Habitat classification: LR.LMR.BF (Pelvetia canaliculata and barnacles on moderately exposed shores) that occurs within the broader habitat LR.MLR.BF (Barnacles and fucoids on moderately exposed shores).

Spiral wrack (Fucus spiralis) occurs in patches on the upper shore rock. Fucus spiralis is characteristic of the habitat LR.MLR.BF.FspiB (Fucus spiralis on full salinity exposed to moderately exposed upper eulittoral rock) that occurs within the broader habitat LR.MLR.BF (Barnacles and fucoids on moderately exposed shores).


Spiral wrack (Fucus spiralis) in its reproductive phase with swollen receptacles at the end of its fronds.

Spiral wrack (Fucus spiralis) in its reproductive phase with swollen receptacles at the end of its fronds.


Ulva spp (Previously Entomorpha spp) 

Bare rock has a patchy distribution of barnacles with thick topshells (Osilinus lineatus), Limpets (Patella vulgata), beadlet anemones (Actinia equina) and the occasional mussel (Mytilus edulis) within rock crevices. 

Barnacles, Limpets (Patella vulgata) and a thick topshell (Osilinus lineatus) occur on the bare patches of rock. 

Thick topshells (Osilinus lineatus) aggregate together in a crevice as a behaviour response to reduce desiccation. 

Barnacle density is relatively low.

Patches of fucoids and barnacle covered rock form a mosaic across the shore with occasional clumps of Ulva spp. LR.MLR.BF (Barnacles and fucoids on moderately exposed shores) and LR.FLR.Rkp (Rockpools).

Ephemeral green seaweeds dominate the pools of the upper shore. Habitat classification: LR.FLR.Rkp.G  (Green seaweeds (Entermorpha spp. and Cladophora spp.) in shallow upper shore rock pools).
Lower down the shore serrated wrack (Fucus serratus) becomes the dominant fucoid, forming a mosaic with barnacles. Habitat classification: LR.MLR.BF.Fser (Fucus serratus on moderately exposed eulittoral rock) that occurs within the broader habitat LR.MLR.BF (Barnacles and fucoids on moderately exposed shores).

Above the rock pools of the lower shore Fucus serratus forms a mosaic with barnacles and an increasing number of red seaweeds including Osmoundea sp., Mastocarpus stellatus and Corallina officinalis. Habitat classification: LR.MLR.BF.Fser.R (Fucus serratus and red seaweeds on moderately exposed lower eulittoral rock) that occurs within the habitat LR.MLR.BF.Fser (Fucus serratus on moderately exposed eulittoral rock) that occurs within the broader habitat LR.MLR.BF (Barnacles and fucoids on moderately exposed shores).

Fucus serratus forms a mosaic with the red seaweeds Osmoundea sp., Mastocarpus stellatus and Corallina officinalis.

Fucus serratus forms a mosaic with  red seaweeds including Osmoundea sp., Mastocarpus stellatus and Corallina officinalis. Thong weed (Himanthalia elongata) also occurs.

Mastocarpus stellatus

Osmoundea sp, Fucus serratus and common limpets (Patella vulgata)


A red seaweed grows on a limpet.

A red seaweed grows on a limpet.

Lomentaria articulata

Limpets, including (Patella vulgata) with a covering of red algae, Dog whelk (Nucella lapillus) and Flat topshell (Gibbula umbilicus).

Limpets (Patella velgata)

As the low tide mark is approached thong weed (Himanthalia elongata) occurs and red seaweeds become more abundant.

Fucus serratus, Osmoundea sp, Mastocarpus stellatus, Ulva sp, Porphyra sp and filamentous greens.

Large rockpools stretch across the mid and lower shore. Within the rock pools is a variety of fauna and seaweed species. Habitat classification: LR. FLR. Rkp (Rock pools).

A shallow mid shore rock pool with coralline, red and green seaweeds. Habitat classification: LR.FLR.Rkp.Cor (Corallina officinalis, coralline crusts and brown seaweeds in shallow eulittoral rockpools).

Within in the rock pools corallinaceae crusts cover much of the exposed rock,  upon which Corallina officinalis then grows.

Corallinaceae crusts, Grey topshells (Gibbula cineraria), limpets and encrusting fauna on a boulder in a rock pool.

Corallinaceae crust


A seaweed

A Red seaweed



A Red seaweed


A red seaweed

A red seaweed

Japweed (Sargassum muticum) is an invasive species which can come to dominate pools and in doing so shade the other species and change the environmental conditions of intertidal rockpool.



Ephemeral green seaweeds 

Seaweeds



Codium fragile 

Gastroclonium ovatum, Corallina officinalis, Corallinaceae crusts, Ulva sp and filamentous greens.

Calliblepharis jubata

Calliblepharis jubata

Calliblepharis jubata

Lower down the shore the brown seaweed, Bifurcaria bifurcata comes to dominate the coralline pools.  Bifurcaria bifurcata dominated coralline rockpool with Corallina officinalis, Corallinaceae crusts, Ulva sp, Sargassum muticum and Fucus serratus. Habitat classification: LR.FLR.Rkp.Cor.Bif (Bifurcaria bifurcata in shallow eulittoral rockpools).

Bifurcaria bifurcata dominated coralline rockpool with Corallina officinalis, Corallinaceae crusts, Ulva sp and Fucus serratus.

Bifurcaria bifurcata dominated coralline rockpool with Corallina officinalis, Corallinaceae crusts, Ulva sp, Sargassum muticum and Fucus serratus.

Bushy rainbow wrack (Cystoseira tamariscifolia), Corallina officinalis, Corallinaceae crusts, Ulva sp, Bifurcaria bifurcata and brown seaweeds.

Bifurcaria bifurcata




Bifurcaria bifurcata dominated coralline rockpool with Corallina officinalis, Corallinaceae crusts, Ulva sp, Fucus serratus and filamentous reds.

Beneath the shade of the Bifurcaria bifurcate, Mesophyllum lichenoides grows.

Gem anemone (Aulactinia verrucosa)

Gem anemone (Aulactinia verrucosa)

Anemones

Anemone


Beadlet anemone (Actinia equina)

Beadlet anemone (Actinia equina)
Snakelocks anemone (Anemonia viridis)

Snakelocks anemone (Anemonia viridis)
Snakelocks anemone (Anemonia viridis)
Coarallinacea crust and Botryllus schlosseri.

Beneath the boulders is a rich under boulder community of cushion stars (Asterina gibbosa), Grey topshells (Gibbula cineraria), Seasquirts (Botryllus schlosseri), Beadlet anemone (Actinia equina), Sponge, Painted topshell (Calliostoma zizyphinum) and Spirorbid polychaetes.  Above corallinacea crust, Corallina officinalis and Mastocarpus stellatus grows.

Cushion stars (Asterina gibbosa)

Netted dog whelk (Nassarius reticulatus).

Worm pipefish (Nerophis lumbriciformis)

At the low tide mark Sand binder (Rhodothamniella floridula) becomes increasing dominant.