Lough Hyne, Ireland’s only saltwater lake, is currently overwhelmed by hundreds of thousands of mauve stinger jellyfish, leading scientists to issue warnings for swimmers to stay out of the water. The unusual congregation of these jellyfish, typically oceanic, coincides with reports along the western coastline from Donegal to Cork. Experts suggest this influx may relate to weak coastal currents allowing oceanic species to migrate closer to shore. Authorities urge caution, as stings from mauve stingers can cause serious reactions, with some individuals even reporting lasting skin discoloration from their tentacles.

Source