Alarmingly high levels of E.coli bacteria have been found in Clifden Bay, Connemara, by a group of secondary school students.
The lack of a proper sewage treatment system in the expanding urban area of Clifden has been identified as the main cause of the pollution. Significantly, the high bacteria levels, which derive mainly from faecal sources, were detected during the winter months.
The five transition year students carried out their work for the Eco-Ballygowan Environmentalist Awards under the supervision of their science teacher, Ms Olivia Staunton. The students opted for the biodiversity category, involving the study of a diverse range of plants and animals in a particular area.
The students selected two shorelines - Clifden Bay and Calla Bay - for comparative purposes. The two bays have many physical features in common, and are about eight miles apart. The sampling took place on Saturdays during October and November of last year, and January of this year.
Of 22 species of algae and lichens sampled, most were far less abundant in Clifden than in Calla Bay, and eight species were not found in Clifden Bay at all. Only common algae like spiral wrack and bladder wrack were common in both sites, the students note.
Clifden Bay also had fewer invertebrate species. However, there were higher numbers of the common mussel, particularly on the shore area approaching the town. The students attribute this to extra nutrients from effluent in the water which is nourishing the filter feeders.
When analysed at a laboratory in Rosmuc, Co Galway, the Clifden samples had 15 times more E.coli per 100 mls than in Calla Bay. Ms Staunton says that the E.coli concentration in Clifden Bay is "serious", at 264 per 100 mls.
"Clifden is a well-known tourist resort, and these samples were taken in January of this year," she noted. "One can only imagine how these E.coli numbers increase in the months of June, July and August." The students have already contacted local politicians, including the Minister for Community, Rural and Gaeltacht Affairs, Mr Ó Cuív, about the issue and the need for a new sewerage system in Clifden.
A spokesman for Galway County Council said that it recognised that Clifden badly needed a sewage treatment plant, and the area had already lost its Blue Flag status in recent years for this reason.
Clifden was earmarked for the current Government expenditure programme, and the local authority had been examining possible sites.
However, it was awaiting approval from the Department of the Environment in relation to an updated preliminary report on the project.