In April 2012 staff from IFI supervised trials using a cockle harvester to remove the invasive Asian clam (Corbicula fluminea) from a section of the river Barrow below St. Mullins. The Asian clam, a native to southern and eastern Asia, Australia and Africa, was first recorded in Europe in 1980 and has spread to most of the major watersheds on the European mainland. The first Irish record came from St Mullins on the River Barrow in April 2010, but subsequent survey work confirmed it’s presence at other sites on the Barrow and also in the River Nore, River Shannon and Lough Derg. These surveys detected densities of up to 9636/m² and give an indication of the potential of this animal to radically alter the aquatic environment.

Cockle harvesting boat on the River Barrow below St. Mullins

The use of a traditional cockle harvester is the latest phase of an investigation by IFI into possible methods of controlling or eradicating the species. The aim of this operation is to evaluate the effectiveness of a range of harvesting methods at extracting young and mature Asian clams from the river bed. The trials significantly reduced the number of clams on the test sites and the results will help inform national management plans for this invasive species. These trials will provide IFI with invaluable tools to help protect our waterways.

Sieving Asian clams from the sediment aboard the cockle harvesting boat