The central and western regional fisheries boards have set up a taskforce to tackle an African weed which has been identified in Lough Corrib, Co Galway.
The plant, described by the Central Fisheries Board (CFB) as "an aggressive alien species", can grow to depths of 20ft, and is choking areas of the lake.
Officials from Galway County Council and the National Parks and Wildlife Service are working with the fisheries boards to control and eliminate the weed.
The CFB says dense infestations can pose problems for angling, boating, environmental and tourism interests.
The fisheries boards are asking the public to contact them if they have identified the weed elsewhere.
An information leaflet can be obtained from the Central Fisheries Board website www.cfb.ie