There's been a spike in the number of jellyfish on Mediterranean beaches this summer. Scientists blame overfishing — and possibly climate change. The British government has put out a warning to its citizens vacationing near those waters.
Up to 150,000 people are treated for jellyfish stings on Mediterranean beaches each year, and that number is on the rise. Along some stretches of Spain's coast, scientists have spotted huge, mile-long blooms of jellyfish, sometimes with 30 to 40 animals per square yard of sea.
Stefano Piraino, a marine biologist at Italy's University of Salento, recently completed a flyover of 200 miles of Mediterranean coast, to monitor growing jellyfish populations. He thinks he knows the reason.
"Overfishing is one reason. Because if we take out the fishes from the oceans, we leave more food in the environment, and jellyfish are very smart," he says. "They can multiply very easily in a very short time — much faster than any vertebrae, any fish in the sea."
Piraino says he believes research will eventually show that climate change is also to blame.