Thousands of years ago the lake became a marine lake, after a submerged reef rose from the sea, creating a landlocked saltwater lake. The jellyfish population were isolated in in the algae-rich lake and began to thrive. The algae are what the jellyfish live on. Twice each day, the jellyfish in the lake swim from one side to the other. The jellyfish do this to get sunlight through the lake water so that the algae can grow.
With no predators, the jellies multiplied in the lake, over time losing their sting, due to the fact there are virtually no predators. Today the lake contains more than 10 million jellyfish that inhabit Ongeim’l Tketau, known as Jellyfish lake to tourists. Because the jellyfish have no sting, swimming in this lake is completely harmless, offering a unique and beautiful experience to many.
The jellies, varying in size from basketballs to blackberries, slowly undulate as they follow the path of the sun across the surface of the lake.
Here are some amazing images from around the internet: