A researcher at the Woods Hole Oceanographic Institution visited Palau and took a dive in the tiny island nation's Jellyfish Lake, and captured video of a swarm of Mastigias.
Jellyfish are familiar to many beachgoers who step around them as they wash up on shore to avoid a nasty sting. But on one western Pacific island there's a saltwater lake where divers voluntarily go swimming with the local jellyfish, and one diver caught the experience on video.
Pat Lohmann, an emeritus researcher at the Woods Hole Oceanographic Institution in Massachusetts, was on the tiny island nation of Palau to study the coral reefs surrounding it. The visit to the lake, aptly named Jellyfish Lake, came at the end of the first day of their efforts.
"Jellyfish Lake was just a fun dive after a full day on the water," Lohmann said.
Lohmann took an HD camera into the water with him to record the experience and the jellyfish as they swam around. [See his video here.]
The main genus of jellyfish in the lake is called Mastigias They are descendents of jellyfish from the ocean that are thought to have ended up in the lake when sea levels were much once higher, extending over the island and filling up the saltwater lake.
Like most jellyfish, Mastigias feed by stinging plankton with their tentacles to disable the tiny animals and capture them. But Mastigias' sting lacks the oomph of other jellyfish species, a good thing for the divers that swim there.
Lohmann told OurAmazingPlanet the swarm of jellyfish around him did sting him, "but very mild, face and arms, everything else was covered with a wet suit. I've had much worse."