There is a 12,000 year old marine lake on the Rock Island of Palau where divers can snorkel safely with 13 million golden jellyfish without the fear of being stung by these marine creatures. It is known as Jellyfish Lake, but locals call it Ongem’l Tketau.
The lake is unique. It has been ‘cut off’ from the ocean, but is still connected through fissures and tunnels in the lime stone. It therefore experiences slight tidal shifts but other organisms have not found their way into the lake.
The jellyfish in the lake are not exposed to their natural oceanic predators anymore, and have therefore no need for a defense mechanism. They evolved accordingly and no longer have tendrils or stingers. The lake is filled with these golden pink jellies. They are found close to the surface as they need sunlight to produce energy.
There are also moon jellyfish, cardinal fish, silversides, gobies, and the jellyfish’s only predator, anemones. Anemones will devour any wayward jellyfish, but because they live in the more shaded areas and the jellyfish live in the sunny areas, it is very seldom and unlikely that a jellyfish will be caught in the tentacles of an anemone.
