They're the blue blobs unnerving swimmers on [Australia's] Gold Coast beaches. The catostylus mosaics jellyfish, which have been spotted washed up on local beaches and floating in waterways over the past two weeks, aren’t new to the Coast and there’s little risk of harm. ... American biodiversity scientist Dr Healy Hamilton had to battle through the jellies to do research in the Broadwater for the past week. “It was like we had to swim through clouds of jellyfish to find seahorses and pipefish,” she said.