The Irish earthworm is under threat from an Australian invader which is, quite literally, stomach-churning, according to research conducted by a Cork student for this year's Esat Telecom Young Scientists Exhibition.
The Australian flatworm (geoplana sanguinea), a smaller, reddish-hued and extremely unfriendly relative of our own common earthworm, anchors its head in the ground and grips its prey using a sticky mucus. It then uses enzymes secreted by a cylindrical tongue, called a pharynx, to dissolve the skin of the earthworm before sucking its insides out.
The Australian flatworm was first recorded in Ireland in 1981 and is believed to have arrived in a consignment of potted plants. Although less well known than its similarly predatory Antipodean neighbour from New Zealand, which arrived on these shores in the early 1960s, the Australian flatworm is now firmly based in a number of Irish counties.
"It consumes the earthworms and, because its body is flat, it's of no benefit to the soil," said Patrick Bourke (15), a student in Colaiste Spioraid Naoimh, Cork, who researched the flatworm as his project. He estimated that his research site in Co Cork, about one-third of an acre, now had a flatworm population of 1,6003,000 and that the earthworm population had declined by 85 per cent as a result.
Without earthworms, soil drainage and soil productivity decline. Patrick believes the Australian flatworm, which appears to have no natural predators in this country, could soon pose a serious threat to agriculture.
There was bad news, too, for oysters, and oyster-fanciers. Robin Patterson (17), Kirsty McArthur (18) and Philip Wheeler (18), from the Methodist College, Belfast, analysed the effects on oysters of copper-based anti-fouling paints which prevent the growth of algae and barnacles on the bottoms of boats. Through a process called leaching, copper from the paints is gradually ingested by filter feeders, such as oysters.
The students found that oysters exposed to the paint had 10 times the normal concentrations of copper in their bodies. The result: death for the oysters within one week and potential blood poisoning for anyone who consumes too many. The students have written to paint manufacturers to advise them of the ecological damage caused by their products.
Other manufacturers who might wish that young scientists were not so inquisitive are makers of household detergents. Aislinn McCabe (16), from St Dominic's High School, Santa Sabina, in Sutton, Co Dublin, investigated the quality of a number of antibacterial detergents to see if they actually killed bacteria.
The result was good news for bacteria, since most of the products were ineffective at killing bacteria or controlling bacterial growth. One prominent anti-bacterial detergent failed to kill any bacteria at all. What does kill bacteria, apparently, is lavender. David Murphy (15) of Drogheda Grammar School, Co Louth, found that by adding tiny quantities of an essential oil (0.5 per cent in dilution), including lavender, geranium or lemon, to liquid soap, the function of the soap in removing bacteria was "significantly more effective". Asthma sufferers may have cause to thank Ciaran Murphy (16), of the Abbey Vocational School, Donegal, who is an asthma sufferer himself. "I decided that most of my problems were to do with the efficacy of the inhalers and not the efficacy of the medicine," he said.
He examined a number of inhalers and found that the most effective was the AeroChamber, which allowed the user to breathe the spray in several gasps, was reasonably portable and increased his capacity to breathe out air from 550 litres per minute to 600 litres per minute. "People are just given the drug and an inhaler, but they are rarely advised which inhaler to get," said Ciaran.
The exhibition is open to the public on Saturday and Sunday