Crabbers claw out a fresh Klondike

The summer people put me to shame, the way they arrive with their senses all a-quiver, their eyes out on stalks. They climb the mountain, wander the rivers, take the long, slow way round the lakes. They miss nothing: orchids, butterflies, birds. They're all Dicky Attenboroughs, lecturing the eight-year-olds; they don't need me.

They even bring us lovely, edible crabs from hunting expeditions on the shore. There's a particular friend, a Dublin woman, who does wonders with a steel hook lashed to half a broomstick - or even, if needs be, with a reorganised wire coat-hanger. Slithering over the rocks at the very bottom of a spring tide, she probes patiently into holes and gullies under the weed and, on a good day, rakes out a succession of pinky-brown Cancer pagurus, the edible crab.

These are, of course, small ones, summer visitors to the shore themselves and not to be compared with the older, more robust specimens, 20cm or more across, that clamber into fish-baited pots set by the crabbers out in the deep. Cancer pagurus prowls the seabed in depths up to 90 metres - far deeper than lobsters - and lives up to 20 years if uncaptured.

This summer has been quite a Klondike for the little half-deckers crabbing off the western and southern coasts: calm, fine weather and peak demand for crab-meat for restaurants. But one image to blunt the appetite is that of the fishermen spending their journey home wrenching off the big pincer-claws of the crustaceans and tossing their stillliving bodies overboard.

The market, you hear, "doesn't want" the brown meat inside the shell - that is, the crab's digestive gland, or "liver" and reproductive organs, which have a quite different texture from the white clawmeat and a different (but richly delicious) flavour.

Some customers might, indeed, be highly dubious of such amorphous-looking paste, having been reared in the half-knowledge that crabs have bits you don't eat - mainly, the animal's internal gills, or "dead men's fingers". But compared with bashing the claws with hammers, wielded with young women factory workers in white gowns and face masks, the process of eviscerating the crab and sorting out its tasty bits is labour intensive and costly.

Crabs also have meat in their claws whatever their reproductive condition, evading the tradition of months when crabs shouldn't be caught. Claws can be frozen and take up little space. There is also the conscience-salving belief that a crab, deprived of its claws, can grow new ones. But how is the crab to feed or defend itself without them?

It is true that crabs and lobsters sometimes lose a walking leg or even a claw by getting in trapped by a rolling rock or seized by some tenacious enemy. The limb is sacrificed by the action of a muscle that fractures it along a special breaking plane - an encircling groove near the base of the third segment, counting outwards from the body. A new limb appears, in miniature, after the next moult and eventually catches up in size with its partner on the other side.

This automatic shedding mechanism may come into play, in fact, in some of the casual wrenching-off of claws. Some fishermen, too, may sportingly snap off only the bigger one, used for crushing the crab's prey and leave the cutting-claw intact. But most of the clawless cripples drifting down to the sea-bed are doomed to a very early death.

In what will probably be seen as a quirky piece of liberal concern, the EU will actually make it illegal, from 2001, to land crab claws without their bodies. Then, presumably, the claws will be snapped off on land and the crabs, if unsold, left to gasp their last on the spot.

Most crabs reach maturity at about three to five years old, having wriggled out of their shell or exoskeleton many times to accommodate their growth. When they moult, and before the new shell hardens, they puff up their size by absorbing water: this is gradually replaced by tissue until the hard corset gets too tight again. A fisherman seen shaking crabs alongside his ear is listening for water as a clue to condition.

Breeding takes place in winter, deep offshore. The female actually mates after moulting - the male may even help her off with the shell - and numbers of soft-bodied mothers-to-be then sit around together in a seabed "nursery", brooding their eggs. There may be as many as two million eggs beneath the V-shaped apron of a large female crab, and she carries them for seven or eight months, hatching them in spring and summer closer inshore.

From now on, with their shells hardened up, the females are in prime condition for whole-crab fishing (5,000 tons are taken in a year). The cooked, shrink-wrapped crab on the supermarket cold shelf has been drowned in fresh water and boiled. Even in whole-crab fishing, there can be a blithe lack of concern for sustainable crabbing. The soft-shelled "discards" - substantial in number, when some crabbers are setting 1,000 pots a day - ought to be tossed back and left to grow on. Instead, they are supplying the bait for the whelk-fishing industry of the south-eastern coast, at half a crab per pot. A Marine Institute scientist, Dr Edward Fahy, will discuss this at the shellfish conference in Cork at the end of September.