Guardian: A vast flotilla of small, virtually undetectable jellyfish have stung hundreds of people on Spanish beaches this week – an event swimmer’s nightmare biologists say will become increasingly common due to climate change and overfishing. The jellyfish attacked three areas near the eastern city of Elche along the stretch of white sand beaches on the Costa Blanca. On Tuesday 380 people were stung, compared with the usual four or five swimmers a day, said Juan Carlos Castellanos of the Elche city …