The demise of a prized fish species in one of the west of Ireland's most important lakes has prompted a campaign to preserve endangered stocks in other waters.
The action, by the Irish Char Conservation Group, follows the disappearance of the Irish Arctic char from Lough Conn in Co Mayo.
The group's concerns are outlined in a document distributed to thousands of households in counties Mayo and Galway over the past week. The group claims that pollution is the cause of the decline and that Government inaction - which it says is in contravention of EU legislation - has exacerbated the problem.
"Arctic char are one of the most beautiful members of the salmon and trout family but are very susceptible to water pollution," said Dr Fran Igoe, ICCG scientific adviser.
The campaign aims to increase local awareness of the problem so that the issue is addressed by local politicians and policy-makers.
The group believes that Lough Conn - one of Ireland's best-known lakes for brown trout and, to a lesser extent, salmon - is being adversely affected by "environmentally unsustainable agriculture", forestry activity, sewage discharge and septic tank/slurry run-off.
It says that the Arctic char has become extinct in the lake because of "nutrient enrichment", caused by increased concentrations of slurry, sewage and fertiliser washed off land, which upsets the water system's natural balance.
When asked by the European Commission to comment on claims that pollution was the cause, the Government claimed that other factors could have contributed, such as an increase in predators in the form of coarse fish. The issue is being cited by the Commission in a case it is bringing against Ireland to the European Court, due for hearing later this year.
The conservation group, comprising angler organisations and environmentalists, claims that the deterioration began with over-enrichment of the water system in the early 1980s. By 1990, there were indications that the Arctic char was extinct.
Arctic char were the first fish to colonise Lough Conn after the most recent Ice Age. They are usually prevalent in deep lakes, though it is believed that they are extinct in up to 40 per cent of large Irish lakes.