The algal bloom identified off the west coast is continuing to kill fish and shellfish in significant concentrations from north Galway to north Donegal.
Up to 80 per cent of stock has been affected on some oyster farms in Donegal, and it is also having a negative impact on sea angling tourism, the Marine Institute has confirmed.
The bloom is caused by Karenia mikimotoi, a phytoplankton of the dinoflagellate group which caused a red tide in 2005 that killed wild fish and shellfish. Samples of this new bloom, first detected in May, are being collected for Marine Institute monitoring by the Irish Coast Guard search and rescue helicopters.
Marine Institute phytoplankton expert Joe Silke said the bloom was naturally occurring. It was not associated with pollution but contained a “toxic irritant” that damaged gills of shellfish, fish and invertebrates.
Irish Farmers’ Association fish farm section chief executive Richie Flynn said if there was a “properly functioning” licensing system in place, farmers could take measures to move stock when such blooms occurred.
