The Irish Coast Guard has said that balls of crude oil which have washed up on the shores of Achill Island, Co Mayo, are harmless and may be due to pollution at sea.
Strollers on Achill’s Keel Beach, which has a Blue Flag, have reported walking on black “tar-like” blobs along the shore this week.
The blobs, known as “tar balls”, first came ashore at high tide on Wednesday.
Beach regular Joanna McNicholas said the “lumps” were visible intermittently and some of them were tangled in seaweed that also came in on the tide.
“The blobs are soft, black and shiny and range in size from about two inches to nine inches in diameter.
“They smell strongly of oil and and are extremely sticky if touched.
“They can easily be mistaken for stones except in bright sunlight, which gives them a glossy shine,” she said.
Tar balls wash up regularly on the US Gulf Coast, emanating from leaks from offshore wells.
Pollution at sea
Irish Coast Guard operations manager Declan Geoghegan said oil pollution at sea sometimes breaks up into balls.
These balls resurface after several years, when they are relatively harmless.
Mayo County Council said the tar samples would be examined and the situation would continue to be monitored.
Last May, foul-smelling globules washed up on the shoreline near Elly Bay, Co Mayo, and on Cross Beach in Erris.
Several residents reported that their animals became ill after attempting to eat them.