Corraline Rock pools - Isles of Scilly

Rock Pooling Destination: Porth Seal, Isles of Scilly, UK. April 2012

The rock pools at Porth Seal vary with those in the upper shore characterised 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, osmundea, grazing molluscs and barnacles.

Below are photographs of some of the organisms in these pools:

Biotope classification: LR.FLR.Rkp.G Green seaweeds (Enteromorpha spp. and Cladophora spp). in shallow upper shore rockpools.

Common prawn (Palaemon sp) seeks cover under Ulva spp

Sea hare (Aplysia punctata) grazes on the green seaweeds 

Biotope classification: LR.FLR.Rkp.Cor Corallina officinalis, coralline crusts and brown seaweeds in shallow eulittoral rockpools. Coralline dominated rock pool with the alien brown seaweed Sargassum muticum, above the pools is a mosaic of fucoids, osmundea, grazing molluscs and barnacles.

Gibbula cineraria on encrusting coralline.

 

Feeding tentacles of polychaetes

Biotope classification: LR.FLR.Rkp.Cor.Bif Bifurcaria bifurcata in shallow eulittoral rockpools. Bifurcaria bifurcate  and sargassum muticum dominate the surface of the rock pool

Ceramium sp

Beadlet anemone (Actinia equina)

Snake locks anemone (Anemonia viridis)

Green sea slug (Elysia viridis)

 Other examples of corraline pools in Cornwall:

Corallina officinalis

What you can see …..an introduction to the major habitats

The environmental conditions and substratum upon and within which marine organisms live varies; each variant has a certain collection of species associated with it and thus represents a specific habitat.

Habitats are broad scale descriptions which can often be further defined to the biotope level. There are a variety of habitats/biotopes that can be encountered whilst rock pooling around the UK. Descriptions of these can be found within the JNCC marine habitat classification for Britain and Ireland V4.5 www.jncc.gov.uk/MarineHabitatClassification.

For rock pooling the principal division for broad habitat types is between Littoral rock and Littoral sediments; the substratum type and environmental conditions are then further subdivided with the addition of species list to classify the different habitats/biotopes.

Littoral Rock

Littoral Sediment