#INLAND WATERWAYS - Trial dredging operations to curtail the spread of Asian clams at designated sites in the lower River Barrow are set to conclude today.

Inland Fisheries Ireland (IFI) employed the use of a a traditional cockle harvesting boat to physically remove the clams from the river bed, in an effort to explore methods of controlling or eradicating what it describes as an "ecosystem-changing invader" in other infested waters.

IFI scientists supervised the trials, using teams of divers to quantify the result of the dredging efforts.

The Asian clam (Corbicula fluminea) is "a most unwelcome addition to the fauna of the lower River Barrow". The bivalve mollusc is regarded as "one of the most notorious aquatic invasive species in the world".

First recorded in the river downstream of St Mullin’s in April 2010, subsequent IFI studies have revealed that the Asian clam is firmly established in the lower Barrow and in the River Nore downstream of Inistioge. Populations have also been recorded in the River Shannon and in Lough Derg.

In one section of the River Barrow the clam has achieved a "staggering" density of almost 10,000 per square metre.

Dr Joe Caffrey, senior scientist with IFI, said of the trial dregding: “It is imperative that every effort is made to control the expansion and spread of this highly adept invasive species.

"The results from these trials will inform future national management plans for this most unwelcome non-native species and will, at the very least, dramatically reduce the numbers of individuals in the test sites.

He added: "In tandem with these trials, research effort is being focused at producing other control methods that can be targeted as this species.”