I spent a few hours on Saturday afternoon investigating the plethora of creatures that inhabit the rock pools around Gylly Beach in Falmouth. I was accompanied by Rachel (my sister) and a friend called Hannah (who is carrying out her dissertation project on the effects of Blue-rayed Limpets on Kelp). We managed to make use of the day’s only few hours of dry conditions (which happened to fall over low water!), and had a great foray amongst the pools and seaweed-covered rocks, finding a superb variety of beasties.
Rockpooling generally is a brilliant activity – there is a child-like element to it (which is probably why everyone else exploring the rock pools was below the age of 10…): peering under pebbles and rocks, and splashing around in the shallows after slippery fish. You never know quite what you might find tucked away in the various cracks and crevices, or clinging to the underside rocks, which adds to the element of discovery.
It is fun to observe the change in species composition as one moves from the upper shoreline down through the supralittoral zone and into the infralittoral fringe: it presents as greater change in animal diversity as if one were to travel from savannah into forest (well, maybe not quite…). The bare upper shore in the splash zone supports Limpets, Whelks, Periwinkles, Beadlet Anemones and seaweeds like Spiral Wrack; this gives way to a richer ecosystem of deeper pools and thicker weed coverage, with various fish and shrimp species living in the tidal pools, along with Hairy Porcelain Crabs, Velvet Swimming Crabs, Snakelocks Anemones, Kelp seaweeds and Coral Weed – gradually the coverage of weed and kelp becomes greater as one approaches the low tide mark.
Anyway – enough rambling: on our particular foray, we found plenty of interesting species. Particular highlights for me included a Pipefish, a green-coloured Beadlet Anemone with the blue beads rimming its mouth (called sphincters); intricately-patterned Blue-rayed Limpets clamp to Kelp stipes in the lower tidal elevations, with Hairy Porcelain Crabs clinging onto the underside of rocks and pebbles, along with Velvet Swimming Crabs embedded in the silt beneath; Hermit Crabs cautiously peer out of their over-sized homes as shadow passes over its pool. These are just a few of the sights I found particularly cool…
Most Beadlet Anemones (Actinia equina) are a dark red colour, but this particular one was an intriguing green hue with the blue sphincters rimming the edge – thus giving it the apt name.
A Hermit Crab peeking out of its encasement
Hairy Porcelain Crab (Porcellena platycheles), which are incredibly adapt at clinging to the underside of rocks and pebbles
The superb Blue-rayed Limpets (Patine pellucida)
Velvet Swimming Crab (Nicora puber)
Purple Topshell (Gibbula umbilicalis)
Painted Topshells (Calliostoma zizyphinum)
dead Barnacle (Balanus perforatus)
Coral Weed (Coralina officianalis)
An interesting sea anemone that appears to be Sagartia elegans