The slaughter was widely condemned yesterday and an investigation involving gardaí, Duchas and conservation officers got under way, following the discovery of the carcasses.
Fishermen have, for several years, been calling for a cull of the seal population, claiming seals interfere with their nets and consume large amounts of dwindling salmon stocks.
Up to 40 dead seals, including five adults, were found at tiny Beginish Island, in the Blaskets area, by divers out with a local club on Wednesday, while five adults were found shot in Brandon Bay yesterday.
Contrary to earlier reports the seals had been bludgeoned and disembowled, Sergeant Mossie O’Donnell, from Dingle, said they had been shot.
“This is a despicable type of crime, which is being fully investigated,” he said.
Duchas regional manager Paddy O’Sullivan also said the evidence pointed to the seals being shot rather than clubbed.
He said the matter would be probed thoroughly and they were also preparing to mount a watch on the seals.
Gardaí, wildlife officers and a veterinary surgeon yesterday went to Beginish, which is about three miles offshore from Dunquin and within a few hundreds yards of the Great Blasket, where they found the carcasses of around 35 pups and five adults scattered along the shoreline.
Environment Minister Dick Roche promised a full investigation, saying he was shocked and disgusted at the sheer brutality of the slaughter. He said the killings were “deeply de-humanising and disturbing” and his department would do everything to bring the perpetrators to justice.
The 600-strong Blasket grey seal colony is one of the most important in western Europe and accounts for about a third of the total Irish seal population.
There were calls for better protection of seals and the need to provide a constant watch over them.