Warning over 'alien' zebra mussels
An underwater invader from Russia has boat owners in Co Fermanagh on high alert.
They were not scanning the lakelands for suspicious periscopes but for a species of mussel that has arrived from the east.
The Northern Ireland Environment Agency (NIEA) warned that the zebra mussel species discovered in Lough MacNean, near the Cavan border, poses a threat to both boats and water treatment plants.
Described by the NIEA as an invasive alien species, the mussels from the Caspian Sea area of south-east Russia are notorious for blocking intake pipes.
Their presence could also upset the natural functioning of the lake system and result in a drop in fish numbers, according to the agency.
John Early, of the NIEA and The Zebra Mussel Control Group, said: "Zebra mussels, native to the lakes of south east Russia, attach themselves on the stony lake bottom but also to any hard surface, such as boats, buoys and water intake pipes, where they can form very dense clusters and are principally spread by recreational water use."
The mussels have already been found in parts of nearby Lough Erne, requiring £100,000 modifications at the Killyhevlin Water Treatment Plant at Enniskillen.
"It is important that water users are aware of the environmental impacts of zebra mussels," said Mr Early.
"The impacts that have been recorded at Lough Erne emphasise the importance of preventing them from spreading to other unconnected lakes. Prevention of spread is an issue of shared responsibility and we are asking all water users to follow the guidance issued."
Signs have been erected at slipways around Lough Erne and at Lough MacNean stressing the need to carefully clean boats and equipment, drain bilge water and removed any plant material attached to the engine or trailer.