Guardian: A deadly form of jellyfish which has caused £1m in losses to salmon farms off Northern Ireland’s coastline has returned to the Irish Sea. Mauve stinger jellyfish were spotted at the weekend along a popular tourist beach on Portrush’s West Strand by an Environment Agency worker. Scientists have confirmed that the small purple creatures were the same jellyfish that killed more than 150,000 salmon in cages off the north Antrim coast last year. The Environment Agency said …