At the end of January 2013, over a one week period, 13 common dolphins were found dead along the Mayo coast. The situation was considered sufficiently unusual to warrant further investigation. The Department of Arts, Heritage and the Gaeltacht commissioned a specialist cetacean veterinarian team to carry out post-mortem examinations on five of the animals. This work was undertaken in Athlone at the Regional Veterinary Laboratories of the Department of Agriculture, Food and the Marine.
There was evidence consistent with entanglement in fishing gear apparent in each animal and the post-mortem findings in all five animals are thought to be most consistent with accidental bycatch in trawl type fishery gear. Common dolphins are plentiful in Irish waters and the Celtic Sea, but are at risk of accidental bycatch by trawling, as they may feed on fish shoals very close to boats.
They are one of twenty four species of cetacean that occur in Ireland and are subject to strict protection under national and international legislation. Minister Deenihan said "I am concerned by any killing of these species, even where accidental. A meeting has been agreed between my officials and the Department of Agriculture, Food and the Marine to examine what further actions may be taken to minimise the risks to dolphins". Minister Coveney shared the concerns of Minister Deenihan and acknowledged "In addition to our own boats, many other European fleets operate in Irish waters, an area that is intensely fished. On the basis of these examinations, it is not possible to determine which of these fleets might have been involved in this incident. The results of these post mortems certainly remind us of the need to further our efforts to reduce incidental by-catch to the lowest possible level across all EU and third country fleets fishing in waters around Ireland".