Watching the bottlenoses

This summer's restless seas and blurred horizons have not been good for whale-and-dolphin watchers, muffled up on headlands or pitching about in boats. In the Shannon Estuary, always vulnerable to Atlantic winds, morning callers to Dolphinwatch at Carrigaholt, Co Clare, hopeful of a trip to find the bottlenoses, have mostly had to be told: "Sorry, we're too churned up today".

But it is still early in August, perhaps the year's best month for watching cetaceans in Irish waters. And the more seriously people look for them, the more they seem to find. Last autumn, the Seabirds and Cetaceans Team of the UK's Joint Nature Conservation Committee published its report on the waters around Ireland. In 17 years of survey voyages aboard Irish Navy ships and ferries and other "vessels of opportunity", it recorded 9,106 individual cetaceans of 13 different kinds.

Its study confirmed the minke as Ireland's most abundant summer whale. This streamlined 10 metre 10-tonner is dramatically the smallest of the rorquals, or plankton-feeding whales (and named for a Norwegian whaling skipper who habitually exaggerated the length of everything he caught). But minke eat much more than krill: summer shoals of sprats help to bring them close inshore, within telescope distance of Ireland's southern and western headlands.

Typically, they are seen feeding in the mouth of the Shannon Estuary, just south of Loop Head, under a halo of circling kittiwakes and shearwaters. Such communal feasts by cetaceans and seabirds are even more spectacular at the plankton-rich upwellings of the continental shelf, far offshore.

Last month, about 80 km west of Loop Head, observers aboard John Petch's ketch Seadrifter, out of Kilrush, came upon a "feeding frenzy" of about 100 common dolphins, and plunging among them were gannets, feeding on small, pink squid. The encounter was a highlight of an exploratory cetacean survey, one of several being led this summer by Dr Simon Berrow.

This dynamic young zoologist, graduate of UCC, is just back from a research stint with the British Antarctic Survey (studying albatrosses, among other birds), and busy picking up the threads of his work with the Irish Whale and Dolphin Group. It was Berrow, with Brian Holmes, also of UCC, who investigated the remarkable community of bottlenose dolphins which have made the Shannon Estuary their home. Now, with a grant from the Marine Institute, they are testing the possibilities for extending whale and dolphin watching to ocean voyages of several days.

In June, the Seadrifter team sailed out nearly 400 km beyond the continental shelf, where appalling weather made visual surveys impossible, but underwater hydrophones picked up the urgent clickings of dolphins, the whistlings of pilot whales, the measured clicks of sperm whales 5 km away in the deep. A further survey, in September, will concentrate on the inshore waters, where bottlenose, white-beaked and Risso's dolphins travel among the common dolphins and harbour porpoises so abundant across the western shelf.

The numbers of minke whales build up inshore through the summer, but a good, calm sea is needed to spot their modest fin and often inconspicuous blow. Minkes are the main attraction for commercial whale-and-dolphin watching in the Sound of Mull, in the Hebrides. There they seem drawn to strong tidal currents, and finding similar conditions off Clare and Galway may help to guarantee the whale-watching customers their sightings and photographs.

Developing a science-based tourist industry to benefit the small rural communities of the Shannon is a personal mission for Simon Berrow and Brian Holmes. Such scientific involvement from the start will be good for "conserving the resource" - protecting the estuary's bottlenose families from harassment and intrusion. It will also avoid conflicts of the kind seen at Cardigan Bay, in Wales, where the bottlenose community has been besieged by watchers in their hundreds, and the scientists and tour-boat operators are no longer speaking to each other.

The Shannon business is starting small - Dolphinwatch at Carrigaholt and Scattery Island Ferries upstream at Kilrush are the pioneer operators - and the trips have none of the circus atmosphere attending the Fungi industry at Dingle.

On a good day, the Shannon bottlenoses can, indeed, "go ballistic", demonstrating speed swimming, somersaults, fluke slapping, breaching and bow-riding, all apparently for their own amusement. But the estuary's dolphin-watchers tend, so far, to be of the discriminating sort, easily rewarded and happy not to press too close to the groups of bottlenose mothers and calves.

The estuary's resident population is perhaps around 80 dolphins, a total which may fluctuate with the supply of salmon. In a feeding area, there may be a gathering of 20 or more, but a more usual group is five to 10. The association and behaviour of the animals is being studied for a Ph D by Simon Ingram of UCC and his work will help evolve a local code of practice for tour boats: already, they avoid one corner of the estuary which the dolphins seem to use for rest.

About half the bottlenose population is now known to the researchers, who have photographed them from the ferry, and there was pleasure in recognising, a few weeks ago, the notched fin of the very first dolphin to be photographed, in 1993.

The Shannon ferry, crossing from Killimer in Co Clare to Tarbert in Co Kerry every half-hour during daylight, makes an excellent platform from which to spot the dolphins. Its skippers have been recording sightings for the Irish Whale and Dolphin Group for more than two years, and these show a marked peak in the two to three hours before low tide. As word of this gets about, the bottlenoses may enjoy watching people rushing around the railings.

Dolphinwatch, Carrigaholt, Co Clare is at: 065-58156