Rockpooling destination: Seapalling, February 2014

The shore at Seapalling is influenced by a series of artificial sea defences that have changed the dynamics of the shore to produce multiple bays comprised of mobile sands with shingle berms in between.

The hard substrate is characterised by a barnacle community with periwinkles, limpets, dog whelks and beadlet anemones. The lower edges of the breakwater harbour occasional seaweeds, whilst beneath the sea defences are a network of tidal pools.

Since October, the deposition of sediments has changed again and a strand line has formed, whilst there has been further die back of seaweeds.

Habitat classifications:

Substrate	LR (Littoral rock)		LS (Littoral substrate)
Habitat	HLR (High energy littoral rock)	FLR (Features of littoral rock)	LS.LSa (Littoral sand)
Biotope complex	LR.HLR. MusB (Mussel and/or barnacle communities)	Eph.FLR.Eph (Ephemeral green or red seaweed communities	LS.LSa.sh (Shingle and gravel shores)	LS.LSa.St (Strandline)	LS.LSa.MoSa.BarSa (Barren littoral coarse sand)
Biotope		LR.FLR.Eph.EntPor (Porphyra purpurea and Entomorpha spp. on sand scoured lower eulittoral rock)

Below are images of some of the organisms you may encounter whilst rock pooling in these habitats:

The sea defences provide an artificial hard substrate amongst the littoral sediments of the shore. During the winter months strandlines of washed up hornwrack (Flustra foliacea) form. Habitat classification: LR.HLR (High energy littoral rock), LS.LSa (Littoral sand) and LS.LSa.St (Strandline).

The sea defences comprise large rectangular boulders that have relatively shear faces. Habitat classification: LR.HLR (High energy littoral rock). The littoral sediments surrounding the sea defences continually experience the dynamic forces of erosion and deposition.  At this time sand has been deposited against the sea defences, while review of this location in October (image below)  shows a lower sediment level that is comprised of sand and shingle.

The same location as above but a few months previous shows how the sediment distributions have changed, from sand and shingle to increased deposition of sand.

Rocky shore communities have formed on the artificial sea defences; barnacles, limpets and periwinkles occur throughout and characterise the biotope complex LR.HLR.MusB (Mussels and/or barnacles in high energy littoral rock).

Spiral wrack (Fucus spiralis) has experienced further die back since October (see image below).

Spiral wrack (Fucus spiralis) in October.

Periwinkles (Littorina sp) amongst barnacles. 

A juvenile dog whelk (Nucella lapillus) amongst barnacles. 

The barnacles covering the rock are of variable sizes indicating a mixed aged community. The dead barnacles provide shelter for a variety of including  periwinkles (Littorina sp)

Limpets within the barnacle community.

Mastocarpus stellatus on a barnacle covered boulder.

The deposition of sand has covered barnacle clad boulders.

Limpets and barnacles ‘emerge’ from the sand, an indication of the relatively recent deposition. 

Nearer to the low water mark, Serrated wrack (Fucus serratus) occurs on a boulder and on the boulders edges ‘emerges’ from the sand.

Beneath the boulder overhangs it is cooler, damp and shaded with interconnecting tidal pools. Barnacles, beadlet anemones (Actinia equina) and dog whelks (Nucella lapillus) occur across these shaded rock faces. 

Sand deposition has filled many of the tidal pools.  Here beadlet anemones (Actinia equina) and common starfish (Asterias rubens) occur where once there was a pool.

Anemones (Urticina spp) washed up last year now inhabit a a pool that has been subject to sand deposition

Anemones (Urticina spp)