Experts trawl for answers as thousands of fish killed
Published 04/10/2015 | 02:30
Hundreds of thousands of fish have been washed ashore on a beach in west Kerry.
The discovery was made by local people two days ago on Sandy Bay in the Maharees, an island near Castlegregory on the Dingle Peninsula.
The phenomenon has never been seen in the area before, at least not in such huge numbers, but experts believe it is a natural occurrence that may be related to the fine weather over the past few weeks.
The fish are mainly sprat but there are also mackerel among the decaying bodies on the shore that will now have to be disposed of by Kerry County Council.
Peculiarly, no birds or scavengers have eaten the dead fish that have been lying on the shore since Thursday.
Locals contacted fisheries expert Kevin Flannery, the director of Dingle's Oceanworld Aquarium.
He believes one of two things happened: either the fish were chased ashore by something in the water or else it was caused by a tidal bloom.
"Either they were being chased by bigger fish, like blue fin tuna or a shoal of mackerel, and got trapped in the corner of the bay.
"The other possibility is that because of the fine weather there are a lot of tidal blooms and Noctiluca, or night light, which occurs where the plankton in the water lights up by night."
The phenomenon of Noctiluca scintillans is also known as sea sparkle. It causes fluorescent blue patches that glimmer and it can be toxic.
Sea sparkle can also be triggered by pollution from sources like farm waste, where an increase in nitrogen and phosphorus causes the plankton to bloom.
"It's a beautiful thing to see but it could deplete oxygen in the water," said Mr Flannery.
He added:"Birds like to catch their fish alive but because of the way they die, the birds won't touch them."