Believe it or not, but the video of these jellyfish seen above wasn’t filmed in the ocean. Instead, the diver is in a marine lake in Palau, called Jellyfish Lake. This body of water is a secluded lake that is fed saltwater from the nearby ocean through cracks in the limestone walls. Despite an abundance water getting into and out of the lake, the animals are essentially trapped. The isolated conditions have led to a reduced level of biodiversity in the lake, but have also led to a massive population of golden jellyfish (Mastigias cf. papua etpisoni). It is debated whether or not the jellyfish have lost their ability to sting. Many sources claim that without the presence of predators, they no longer needed the ability to sting. Additionally, people claim they lost their stinging cells because they rely so heavily on photosynthesis to attain any required nutrition. Despite these claims, many divers still report minor stings on some of the more sensitive parts of the body. Regardless of the claims, the chances of a diver actually getting stung by a golden jellyfish in Jellyfish Lake are extremely slim.
Stepping away from the extremely popular Jellyfish Lake, Palau has roughly 70 or more other marine lakes spread throughout multiple islands. Other jellyfish, such as the moon jellyfish, exist in the lakes, but the golden jellies seem to be the more dominant species.