AS a boy, I would beach-comb at the foot of high chalk cliffs beside the English Channel - a greener and saltier stretch of sea, as I remember it, jostling in winter with unpredictable and loutish sorts of wave.
Along with the mermaids' purses vacated by infant dogfish, and the papery sponges deserted by baby whelks I collected cuttlebones, streamlined and oval, white as the chalk of the cliffs. They were also as light as balsa wood, but too brittle to carve into model aircraft. We had no canary to peck at them for lime, and no need to grind them up for toothpaste, as some apothecaries used to do.
Today, my Atlantic precinct is not really cuttlefish territory. A few bones have washed in now and then over the years: once, enough to bring up for the hens, which regarded them blankly. But when the weather settled from the recent storms, I went down to the strand to look for them especially. This was to please a friend, a marine biologist who monitors the tideline for clues about events and trends in the sea.
Towards the end of January, he found and collected hundreds of cuttlebones - whole plastic bags-ful - on beaches from Galley Head, in Co Cork, right round to Ballinskelligs Bay and Ventry on the Dingle Peninsula. They had been ushered along the south coast by the long run of easterly gales and carried around the corner by the clockwise current in these parts. When the gales went, south-west again, he thought, the bones might get up as far as me.
The storm-sea's were pretty big, if not quite as mountainous as the weathermen were prophesying. ,They scooped away most of the [fluffy deeps of sand deposited during the easterlies, so that to reach the sea's edge now is to walk downhill: such unauthorised removal!
So far, however, nothing much has drifted in on this smooth, scoured slope but a familiar tangle of sea-rods and the odd fish-box (useful for geraniums). Perhaps the last of the cuttlebones have foundered: a thousand little snowy boats, a featherweight flotilla, wedged among the black rocks of Slyne Head.
What is a cuttlefish, anyway, and why collect bags-ful of its bones?
I have written here about the squid, the charmingly-named Loligo, fastest invertebrate in the ocean and a tasty source of protein (like scallop-flavoured kidney with a hint of snail). The squid is pelagic, a restless, nervy hunter of the open sea, using jet propulsion to shoot backwards or forwards and grabbing its prey with to arms mounted on its head.
The cuttlefish, the Sepia, is a close relative but it dwells mostly among the eel-grass of shallow, sandy bays, and stripes itself like a tiger to blend into the shadows. Like the squid, it is really a mollusc, a cephalopod which has risen above life on the sea-bed. Both animals have internalised their shells as a single "bone". In the squid this is fairly vestigial, a stiffener, but the cuttlefish has turned it into a gas-filled buoyancy aid, as controllable for rising or descending as the tanks of a submarine.
I could go on about the cuttlefish's amazing capacities: its chameleon changes of colour and pattern, its vanishing act with the aid of a cloud of ink. It is touching to know that young cuttlefish have, to learn from experience to sneak up on crabs )from behind. But their lives are short, and their bare bones are what concern us.
Though cuttlefish are spread fairly widely around western Europe, they show a preference for the warmer waters. The main species, Sepia officinalis, is a robust animal up to 30 cm long, and the frequent stranding of it's bones on our south-east coast, in two sizes, suggest a spawning population somewhere nearby
Of the other two kinds, S. orbigny has a little spine at one end of the bone, and the bone of S. elegans is, as my biologist friend put it, "a small, slim job" - one arrived in the post almost at once, from a 10-year-old reader who had found it on a beach in Co Wicklow and wanted to know what it was.
The real home ground of the cuttlefish extends from the English Channel down into the Mediterranean, so any increase in its abundance and range around Ireland would say something highly significant about the temperature of the sea. As a practical indicator of global warming, the stranding of cuttlebones has strong appeal highly visible, easily counted and sampled. This is why my friend is so closely interested in the extent of the recent windfall and the ratio of species within it.