The attack took place on Tuesday afternoon of last week around 70m off the shoreline. The man needed medical attention, senior county council officers said.
The seagull swooped on the man — believed to be a visitor to the area — and returned a second time, even though the swimmer tried to fight the bird off.
The man beat off the gull but it drew blood from his hand. Lifeguards directed him to Kerry General Hospital where it is understood he received tetanus shots.
Brendan O’Connor, water safety officer with Kerry County Council, said in his 40 years of beach and coastal activities, this was the first such attack ever reported by lifeguards in Kerry.
Mr O’Connor believes it is part of a pattern of unusual behaviour by gulls. The bird in question was a great black-backed gull, rather than a herring gull, he said. The black-backed gull can have a wingspan of up to 1.7m.
“He broke skin, pecked him, and came back for another bite,” the officer said. The man was simply swimming and was not doing anything unusual “when the gull swooped on him”.
The swimmer, who was near the buoys off Fenit beach, tried to summon the attention of two lifeguards while attempting to beat off the gull.
The attack is the latest in a number of extraordinary reports of aggressive behaviour by seagulls in Kerry this year, including the killing of two mountain ewes near Lispole and an attack on a motorcyclist.
Micheál Ó Coileáin, council environmental officer, said the fact that there are no landfill sites now in Kerry, or indeed the region, may be a factor in the gulls’ strange behaviour, including the movement further inland in search of food.