Native Irish fish are being driven to extinction as farming, forestry and road-building destroy their habitats.
The native pollan is in dramatic decline here and about a third of Arctic char populations have disappeared over the past 30 years.
The losses of these and other unique native fish species including shad, trout and lamprey are detailed in a Royal Irish Academy publication, Biology and Environment: Threatened Irish Freshwater Fishes, launched yesterday by Minister of State in the Department of Communications, Marine and Natural Resources Pat the Cope Gallagher.
The studies in the volume detail the species under threat, the causes of their decline and the failures of our regulatory framework to protect them.
The document takes "a holistic approach to these fishes in Ireland", stated Dr Fran Igoe of the Irish Char Conservation Group, who wrote a number of the papers.
Ireland holds subsets of common fish such as the brown trout that have been shown through genetic studies to be unique in the world, he said.
"Our brown trout are far more diverse than we previously thought," he said yesterday at the publication's launch at the RIA in Dublin. Unique tout forms include the gillaroo, ferox and sonaghen.
The pollan is another important native species that has declined dramatically in just a few decades. "The pollan is unique in Ireland in that it doesn't appear anywhere else in western Europe," he stated. "They are very unique not just in an Irish context but internationally."
The twaite shad was caught by the net-full 20 years ago in the Slaney estuary but in 2003 the total catch was just four fish. It has disappeared from the Rivers Suir and Slaney and now is only found in the Barrow, he said.
Another truly unique species is the Arctic char.
They first arrived in Ireland at the end of the last Ice Age, almost 10,000 years ago, he added. "They are possibly one of the oldest fishes in Ireland."
Yet they are suffering the effects of modern pollution. A full 30 per cent of the 74 known lake populations of the Arctic char have become extinct, Dr Igoe said.
The reasons for their decline include the effects of farming, urban development, road building and forestry, stated Shannon Regional Fisheries Board senior fisheries environmental officer Mike Fitzsimons.
Habitat damage is putting native Irish species under pressure.
Of the 40 pristine habitats noted in a 1982 study, only one remained by 1995, Mr Fitzsimons said.
Nitrate and phosphate runoff from farming, construction damage and subsequent pollution caused by road building and upland forestry activity inflicted particular damage, he said.