Rockpooling Destination: Porthgwara, March 2016

The rockyshore comprises sand scoured boulders and bedrock with rockpools. Habitat classification: LR.FLR.Lic (Lichens on supralittoral and littoral fringe rock), LR.HLR.MusB (Mussel and/or barnacles communities), LR.FLR.Rkp (Rockpools) and LS.Sa (Littoral sand).

The rocky shore is comprised of large boulders and bedrock that experience alternating variations in sand scour from the surrounding sandy shore. As a result barnacle cover is low and scour tolerant seaweeds thrive in the shallow sand filled rockpools. Between the boulders are limpets, periwinkles, topshells and dog whelks together with patches of seaweed.

Below are images of some of the organisms you may encounter whilst rockpooling on the shore:

Yellow, grey and black lichens cover the supralittoal and littoral fringe rock. Habitat classification: LR.FLR.Lic (Lichens or small green algae on supralittoral and littoral fringe rock) EUNIS: B3.11.

Much of the rock of the littoral fringe/ upper shore is covered in patches of green algae/lichen that in some instances has overgrown the barnacles. The remainder of the rock is colonised by sparse barnacles, limpets, rough periwinkles and small periwinkles. 

Rough periwinkle (Littorina sp)

Barnacle, seaweed and general epifaunal cover is patchy among the boulders of the shore that are subject to rolling and sand scour; both of which limit the barnacle communities expansion. LR.HLR.MusB (Mussel and/or barnacle communities) EUNIS A1.11.

A limpet is buffeted from the waves by a small outcropping ridge on the boulder.

Seaweeds such as, Cladophora rupestris, Corallinaceae crusts and reds seaweeds occur in shaded damp enclaves between the boulders.

The rockpools of the shore hold the greatest diversity of fauna and seaweeds. Shallow sand filled coralline rockpools are encrusted by coralline seaweeds (Corallinacea crusts and Corallina officinalis), those that are more sheltered have less sand and support more anemones (Actinia equina), china limpets (Patella ulyssiponensis) and thick topshells (Osilinus lineatus) together with sand tolerant seaweed species.

The cover of fucoids and robust red seaweeds increases in and around rockpools and on bed rock of the lower eulittoral. Comprising a red seaweed under-story  of species such as,  Corallina officinalis, Mastrocarpus stellatus and Geldium sp. beneath a fucoid canopy.

A flat periwinkle on Fucus sp

The sand filled rockpools of the lower shore also support a diversity of sand tolerant seaweeds. Habitat classification: LR.FLR.Rkp.SwSed (Seaweeds in sediment filled rockpools) EUNIS: A1.413.

With increased quantities of sand, epifauna decrease and seaweeds, especially sand tolerant species, increase and include Chondrus crispus, Ceranium sp, Clodrophora sp, Sargassum muticum, Bifucaria bifurcata, Rhodothamniella flordula.

Sargassum muticum and sand tolerant seaweeds.

The requirement for seaweeds to withstand smothering is key within these rockpools.

Rockpooling Destination: Revisit West Penwith, December, 2015

The rocky shore is comprised of boulders and bedrock with rockpools, crevices and gullies. Habitat classification: LR.HLR (High energy littoral rock) EUNIS: A1.1 , LR.FLR.Rkp (Rockpools) EUNIS:A1.41 and LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock) EUNIS: B3.11

The rocky shore is a high energy environment comprised of boulders and bedrock with rock pools, crevices and gullies.

The high energy environment of the shore leads to an extended lichen zone, that descends over much of the boulder field, which apart from Littorinids is relatively barren. Patches of lichens extend further down into the barnacle communities, which dominate from the upper to lower shore, interdispersed by shallow coralline rockpools in the mid shore, and deeper cobble filled rockpools on the lower shore. As the low tide mark is reached wave tolerant seaweeds lace the gullies.

Habitat classification:

Substrate	LR (Littoral rock)
Habitat	LR.HLR (High energy littoral rock)			LR.FLR (Features of littoral rock)
Biotope complex	LR.HLR. MusB (Mussel and/or barnacle communities)		LR.HLR.FR (Robust fucoid and/or red seaweed communities)	LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock).		LR.FLR.Rkp (Rockpools)
Biotope	LR.HLR.MusB.Cht (Chthamalus sp on exposed upper eulittoral rock)	LR.HLR.MusB.Sem (Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock)		LR.FLR.Lic.Ver (Verrucaria Maura on  littoral fringe rock)	LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock)	LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools)

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

A 'By the wind sailor' (Velella velella)  washed up high onto the shore. This is a pelagic hydrozoa that is often washed up onto shores during the winter months.

Lichens have a patchy distribution, covering the larger and more stable boulders and bedrock of the supralittoral and littoral fringe rock. Habitat classification: LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock) EUNIS: B3.11.

Many boulders are too mobile to facilitate lichen growth, in such circumstances lichen growth is restricted to areas surrounding 'protected' crevices.

The boulders of the littoral fringe support a community of  rough and small periwinkles with seasonal growths of green ephemeral seaweeds. Towards the lower extend of the littoral fringe rock, sparse barnacles are found. On the boulders where the V. maura is absent the littoral fringe is identified by the presence of other organisms, including rough (Littorina saxatilis) and small periwinkles (Melarhaphe neritoides) and sparse barnacles. The ineffective application of the JNCC and EUNIS habitat classification to the littoral fringe boulder habitat is rectified by the much broader 1993 phase 1 habitat classification which seems to capture these environments under the boulder habitat classification which is in turn is listed under the EUNIS website as comparable to the habitat classification supralittoral rock (lichen or splash zone).

On stable bedrock and larger boulders  V. maura is evident. Common limpets (Patella vulgata), sparse barnacles and an increased diversity of periwinkles (Littorina sp)are also present. The mobile organisms congregate within crevices, nooks and crannies or the leeward sides of rock in a bid to avoid wave exposure.

Littorinid identifications helped by Ian Smith..... 

Rough periwinkles (Littorina saxatilis agg)

Rough periwinkles (Littorina saxatilis agg)

Rough periwinkles (Littorina compressa)

Rough periwinkles (Littorina compressa)

Rough periwinkles (Littorina sp)

The bedrock of the upper eulittoral supports barnacle communities and shallow coralline rockpools. Patches of the lichen, Lichina pygmaea occur on certain rock faces, as does Verrucaria mucosa, whilst the crevices support mussels (Mytilus edulis), periwinkles and  beadlet anemones (Actina equina). Habitat classification: LR.HLR.MusB.Cht (Chthamalus sp on exposed upper eulittoral rock) EUNIS: A1.112 and LR.HLR.MusB.Sem (Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock) EUNIS: A1.113.

Patches of Lichina pygmaea show seasonal die back.

Barnacles

Coralline rockpools occur throughout the bedrock of the eulittoral. During the winter months the ephemeral seaweeds of the pools have died back, as too has those corallinaceae crusts that were exposed to the sun. China limpets (Patella ulyssiponensis),  M. edulis and the seaweeds Corallinaceae crusts, Corallina officinalis, Chondrus crispus and ephemeral greens can be found within these pools. Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools) EUNIS: A1.411.

Mid eulittoral bedrock and less stable boulders, support a more patchy distribution of barnacles, and appear 'pinker' as the granite colour can be seen. Robust fucoids cling on in this environment and between the boulders are filter feeders and robust red seaweeds and beadlet anemones (Actina equina) and among boulders in sheltered gullies are dog whelks (Nucella lapillus) and topshells. Habitat classification: LR.HLR.MusB.Sem (Semibalanus balanoides on exposed to moderately exposed or vertical sheltered eulittoral rock) EUNIS: A1.113.

A flat topshell (Littorina sp) found among the robust fucoids.

Where wave exposure and scour from pebbles and cobbles is high, faunal cover is low.

Bedrock of the lower eulittoral supports an ever increasing diversity of filter feeders, that form 'turfs' with the robust red seaweeds.Habitat classification: LR.HLR.FR (Robust fucoid and/or red seaweed communities) EUNIS: A1.12

Sponges occur beneath shaded over hangs.

Red seaweeds including, Palmaria palmata, Corallinaceae crusts and foliose reds, lace a gully of the lower eulittoral. 

Red seaweed diversity is highest on the lower eulittoral, comprising Calliblepharis sp, Fucus serratus,  Chondrus crispus, Mastrocarous stellatus, Corallinaceae crusts, Corallina officinalis,  Geldium sp and others.

The coralline rockpools of the lower eulittoral support higher densities and diversity of red seaweeds and anemones. Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools) EUNIS: A1.411.

In those rockpools filled with coarser sediment the diversity is less.

Rockpooling Destination: Revisit West Penwith, St. Loy September 2015

The shore is a high energy environment, comprised of boulders and bedrock, with crevices, rock pools and gullies.

Fauna are relatively sparse among the supralittoral and little fringe boulders, increasing on stable bedrock of the upper shore and within the rockpools, crevices and gullies of the mid and lower shore.

The supralittoral and littoral fringe rock is charecterised by lichen communities, whilst barnacle communities occur across the rest of the shore, inter-dispersed by rockpools. As the lower shore is reached, robust wracks and red seaweeds come to dominate.

A river flows onto the shore and beneath the boulders.

Where conditions are sheltered enough, a seasonal strandline forms.

Habitat classification:

Habitat	LR.HLR (High energy littoral rock)		FLR (Features of littoral rock)
Biotope complex	LR.HLR. MusB (Mussel and/or barnacle communities)	LR.HLR.FR (Robust fucoid and/or red seaweed   communities)	LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock).		LR.FLR.Rkp (Rockpools)
Biotope	LR.HLR.MusB.Cht (Chthamalus spp. on exposed eulittoral rock)	LR.HLR.FR.Him (Himanthalia elongata) and red seaweeds on exposed to moderately exposed lower eulittoral rock	LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock)	LR.FLR.Lic.Ver (Verrucaria Maura on littoral fringe rock)	LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools)		LR.FLR.Rkp.FK (Fucoids and kelp in deep eulittoral rockpools)
Sub Biotope	LR.HLR.MusB.Cht.Cht (Chthamalus spp. on exposed upper eulittoral rock)			LR.FLR.Liv.VerB (Verrucaria maura and sparse barnacles on exposed littoral fringe rock)	LR.FLR.Rkp.Cor.Cor Coralline crusts and Corallina officinalis in shallow eulittoral rockpools	LR.FLR.Rkp.Cor.Bif (Bifurcaria bifurcata in shallow eulittoral rockpools)

Below are images of the habitats and organisms you may encounter on this shore:

The exposed nature of the shore leads to an extended lichen zone; within this zone the boulder field is comparatively barren, characterised by lichen communities and periwinkles. At the lower extent of the splash zone barnacles occur at low density. Habitat classification: Biotope complex: LR.FLR.Lic.(Lichens on supralittoral and littoral fringe rock) ENUIS: B3.11 containing the biotopes: LR.FLR.Lic.YG (Yellow and grey lichens on supralittoral rock) EUNIS: B3:111 and LR.FLR.Lic.Ver (Verrucaria maura on littoral fringe rock) EUNIS: B3:113 the latter also contains the sub biotope: LR.FLR.Liv.VerB (Verrucaria maura and sparse barnacles on exposed littoral fringe rock) EUNIS: B3:1131.

Upper shore boulders support barnacles and a range of gastropods including limpets (Patella spp), thick topshells (Osilinus lineatus) and periwinkles (Littorina spp). The seaweeds Fucus sp and Catenella caespitosa and the lichen Verrucaria mucosa occur as patches on the boulders.  Habitat classification: Biotope complex LR.HLR.MusB (Mussel and/or barnacle communities) EUNIS: A1.11.

The upper shore bedrock is covered in dense barnacles (predominantly Cthamalus spp) interspersed by limpets (Patella vulgata) and patches of Lichina pygmaea. Habitat classification: LR.HLR.MusB.Cht.Cht (Chthamalus spp. on exposed upper eulittoral rock) EUNIS: A1:1121.

Within the barnacle communities tufts of fucoids are able to grow where there is sufficient shelter from wave exposure. Seaweed species also thrive within the rockpools that punctuate the shore. Small shallow coralline rockpools are covered by pink corallinaceae crusts which are in turn overgrown by ephemeral greens (Ulva spp) and a variety of reds including, coral weed (Corallina officinalis). China limpets (Patella ulyssiponensis) and juvenile blenny (Lipophrys pholis) also occur within the rockpools.  Habitat classification: LR.FLR.Rkp.Cor.Cor (Coralline crusts and Corallina officinalis in shallow eulittoral rockpools) EUNIS: A1.4111.

Deeper coralline rockpools support a higher abundance and diversity of seaweeds. Including ephemeral greens (Ulva spp and Cladophora spp), a variety of reds including, Corallinaceae crusts, Corallina sp, Mesophyllum lichenoides and the invasive brown seaweed, Sargassum muticum. S. muticum can have detrimental effects on coralline rockpools because it grows and blocks out the light, changing the environmental conditions from that which the indigenous seaweed species are adapted. Habitat classification: Habitat classification:  LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools) EUNIS: A1.411.

On the mid and lower shore other seaweed species are also prolific within the coralline rockpools, including (from top right to the left) ephemeral green seaweeds such as Ulva spp and Cladophora spp, the brown forking weed (Bifurcaria bifurcata) and on the lower shore brown wracks and kelp. A range of smaller epiphyte seaweed species also occur. Habitat classification: LR.FLR.Rkp.Cor (Coralline crust dominated shallow eulittoral rockpools) EUNIS: A1.411, LR.FLR.Rkp.Cor.Bif (Bifurcaria bifurcata in shallow eulittoral rockpools) EUNIS: A1.4113 and LR.FLR.Rkp.FK (Fucoids and kelp in deep eulittoral rockpools) EUNIS: A1.412.

On the lower shore the seaweeds are no longer confined to the rockpools. Thong weed (Himanthalia elongata) and kelp cover the under-storey reds. The remaining bare rock is covered by barnacles and limpets. Habitat classification: LR.HLR.FR.Him (Himanthalia elongata) and red seaweeds on exposed to moderately exposed lower eulittoral rock EUNIS: A1.123.

Other seaweed species present include a variety of robust fucoids and reds. (Anticlockwise from  top right) Fucus serratus; kelp (Laminaria sp); Mastrocarpus stellatus and Codium spp; Cladophora rupestris, reds and Corallinaceae crusts; and Corallina officinalis. Limpets, grey topshells (Gibbula cineraria) and a variety of faunal turfs also occur. Habitat classification: Biotope complex, LR.HLR.FR (Robust fucoid and/or red seaweed communities) EUNIS: A1.12).

Anticlockwise from top right, Gelidium spp and Osmundea spp, Codium spp; Gelidium spp; and Corallina spp.

Palmaria palmata and ephemeral green seaweed (Ulva spp formally Entermorpha spp).

Where conditions allow within the broader biotope complex of robust fucoid and red seaweed habitat, the robust reds may form turfs. On the lower shore these turfs are restricted to patches on boulder edges. The turf comprises Corallinaceae crust, upon which Mastrocarpus stellatus, Chondus crispus and Corallina officinalis grow, above  Lomentaria articulata, Gelidium sp and Osmundea sp occur. That rock not covered by Corallinaceae crust supports barnacles, limpets and topshells. Habitat classification: Biotope complex, LR.HLR.FR (Robust fucoid and/or red seaweed communities) EUNIS: A1.12).

At the low tide mark the red seaweed turfs extend across the rock. Young Himanthalia elongata grow among a turfs of red seaweeds that comprise, Corallinaceae crusts, Corallina officinalis, Mastrocarpus stellatus, Chondrus crispus, Osmundea sp, Gelidium sp and Lomentaria articulata.  

The low tide mark corresponds to a dramatic increase is kelp abundance and red seaweeds turfs extend over available rock. Habitat classification: ILR (Infralittoral rock).

Looking among the kelp blades you may be lucky and spot a blue rayed limpet (Patella pellucida).

A revisit to an overhang found little change since October 2014, except it was not clear to discern the presence or absence of the fried egg anemones  (Actinothoe sphyrodeta).

The same overhang in October 2014. Such overhangs provide shade, enabling subtidal species such as, fried egg anemones (Actinothoe sphyrodeta) to occur within the rockpool and enables Coralline crusts, Serpulid polychaetes  and breadcrumb sponge (Halichondria panicea)to extend up the shaded boulder sides; Grey topshells (Gibbula cineraria) also occur.