One of the world's most dangerous invasive species is threatening to devastate our salmon rivers, experts warned.
The harmless-looking Asian clam, which forms a carpet of shells on the river bed, has been found in the Nore and Barrow in Kilkenny and Carlow.
Dr Joe Caffrey, Inland Fisheries Ireland senior research officer, said it has the potential to be the most dangerous invasive species in the country.
"If we are to win the battle against invasive species, we must be biosecurity aware and actively stop the spread of these pernicious species.
"The Asian clam probably represents one of the most potentially damaging invasive species to reach our shores. It is imperative that every action to bring it under control is taken."
In the US, the Asian clam causes an estimated $1bn (e776m) of damage every year.
It keeps out all other life and has the potential to destroy salmon, brown trout and sea lamprey populations.
It has been found in dense populations, with almost 10,000 clams per metre in the Barrow and further populations in 7km sections of the river downstream of St Mullins.
Intensive surveys are to be carried out on the Nore, Barrow and Suir over the coming weeks.