WHEN jellyfish vanish, it’s usually cause for celebration. But their disappearance from Jellyfish Lake in Palau, Micronesia, could act as an early warning of severe weather events caused by El Ni帽o and La Ni帽a.
The saltwater lake is normally home to more than 10 million mastigias jellyfish, but during the strong La Ni帽a event of 1998 they vanished. “The dive guys came back shocked, saying the jellyfish had just gone,” says Michael Dawson, a biologist from the University of California, Davis.
His team began recording jellyfish numbers, as well as temperature and salt levels in the water.…



