NATURE Rock pools’ colourful residents

Rock-pools’ exotic performance


Marine Life
John Paul Tiernan

I was jealous of the divers slipping bath-like into the water two hours before sunset on a long evening last week. The sea in May is as cold as any day in December, but the air was warm, the sun was still up and the water looked quietly welcoming.
Returning home from a surf mission up north, and without snorkelling equipment we were bound pitifully to the shore to watch their bubbles on the surface while the divers watched whatever was hiding behind fronds of kelp 20 metres below. They were scuba divers, diving with tanks, regulators, rules and buddy systems.
Scuba is fun and useful when serious research has to be done under water, but on this evening all I wanted was a mask and fins and the simple liberation of free-diving.
An hour later, crouched with camera, I had forgotten about the divers and the deep. My enthusiasm for the shore had been renewed. I couldn’t get enough pictures of the most colourful rock-pool I’ve ever seen: 2 feet square and a humble 2 inches deep, it was populated by a sea of life.
Green, pinkish-red and brown seaweeds grew like decorative installations beside evenly spaced peach-yellow limpets covered pimple-like by barnacles, all out-competed for boldness and exoticness (and space on my camera’s memory card) by the flamboyantly brilliant orange and maroon Beadlet Anemones.
When Beadlet Anemones are left high and dry by the dropping tide, they withdraw themselves into a slimy brown blob, unattractive and not even hinting at how good a show they can put on when underwater. There, and despite years of looking at these animals, they still appear to me as if they might not belong to an Irish shore. Their tender structures, rich colour and delicate wavering tentacles look like relics of a warmer sea or maybe another planet depending on your imagination.
They wouldn’t just impress me I thought. This rock-pool and those extra-terrestrial anemones would probably grab a whole classroom if they could only see them. There’s no entrance fee to the intertidal zone, and a teacher looking for an economical 2010 school outing could find it here.
The Heritage Council’s highly successful Heritage in Schools Scheme www.heritagecouncil.ie/education can tell you more about the expert in your area who can advise you on where to find a good site and answer the endless questions a living rock-pool such as this will generate.
Visits to the intertidal should be made at low spring tides which occur between 11am and 2pm for three or four days twice a month.  This year, May 13 to 18 and 27 to 30 and June 13 to 16 and 26 to 29 will be good dates, tide-wise, to go to the shore. Put them in your diary.

John Paul Tiernan Louisburgh, runs www.irishmarinelife.com, a website dedicated to the creation of knowledge of our marine ecosystems. He is currently studying for an MSc in Marine Science.