In a recent article I stated that most dive destinations are renowned for one thing in particular (like humpback whales in the Kingdom of Tonga), but in Palau everything underwater is so diverse and wonderful it’s hard to narrow it down to just one.
I was mistaken.
The Micronesian archipelago of Palau is home to a lake that is full to the brim with completely harmless jellyfish. Jellyfish Lake is a stark (but awe-inspiring) contrast to the breathtaking drift dives and spectacular coral reefs surrounded by year-round tropical water that you can expect of a Palau diving trip.
Jellyfish lake is nestled amongst a vast expanse of forest on Eil Malk Island. Eil Malk is part of the Rock Islands, which is comprised of around 445 mostly uninhabited limestone islands. After a short hike, you arrive and take in the view of the lake and it’s surrounds. Emerald water, bordered by dense jungle and lined with a blanket of perfect blue from a cloudless sky. From above, it’s hard to see what all the fuss is about. Sure, the lake and the vegetation surrounding it are beautiful, but it’s not until you enter the water that you truly believe the hype surrounding Jellyfish Lake.
The Jellyfish Lake is a snorkel-only site, and as you descend beneath the surface on a single breath you are overcome by feelings of serenity and wonder as the millions of jellyfish rise above and below you.The jellyfish that inhabit the lake are giant golden marshmallows, like droplets of soft liquified sunshine floating all around you. The giant jellies that call this marine lake home are either moon or golden jellies, and there are thought to be 10 million of these in Jellyfish Lake.
Jellyfish lake is a marine lake, so when you first dive down you might be surprised by the salty taste of the water. Once connected to the ocean, the 12 000 year old Jellyfish Lake is now isolated from the rest of the sea creating a mini-ecosystem where the jellyfish is king. While the lake is relatively isolated from the surrounding ocean, it’s filled with saltwater thanks to a spiderweb of tunnels and fissures through the limestone of an ancient reef. This disconnection from the open ocean has encouraged the evolution of an eco-system lacking in diversity, but abundant with Jellyfish. These jellies no longer require their stingers. With few natural predators they no longer need this characteristic, making snorkelling with the millions that inhabit this bizarre ecosystem a pain free and phenomenal experience.
There are dozens of these marine lakes like Jellyfish Lake throughout the Rock Islands. This particular lake however is unique in the fact that it has an anoxic layer along the bottom, which is one reason why scuba diving is not allowed in Jellyfish Lake. The last 15 meters of the lake contains high concentrations of hydrogen sulfide which can be absorbed through the skin of a diver, leading to death. Jellyfish are also delicate creatures, and air bubbles created from breathing through scuba apparatus can travel through their flimsy bodies, irreversibly damaging them.
Everyday, the resident Golden jellyfish make the arduous migration from one side of the lake to the other, following the movement of the sun. Strangely enough, the Golden jellyfish have a strict schedule they like to adhere to. In the morning they move from the centre of the western basin to the eastern basin, then in the afternoon head to the western side of the lake, finally propelling themselves to the western basin where they spend the night.They migrate in such a way to gain as much exposure to the sun as they possibly can, revolving as they move so each part of their body receives some rays. Golden Jellyfish photosynthesise zooxanthellae living in their tissues and this symbiotic relationship provides them with their food source. Whilst these jellyfish have evolved to lose their stinger, they are still faced with a natural predator quite literally lurking in the shadows. The ethereal Golden Jellyfish avoids shadows not only so it can receive meet its daily dietary requirements, but so it can avoid an attack from an anemone living on the outskirts of the lake.
The Moon jellies don’t have as much of a rigid routine as the Golden Jellyfish, propelling themselves here, there and everywhere. Moon jellies are the opposite of the Golden Jellyfish who seek out and thrive in the sunshine. These jellyfish rise to the surface every night to feed in the light of the moon.
How to get there
How many places in the world can you swim with thousands of harmless jellyfish?
For that reason, most Palau diving live aboards will include a visit to Jellyfish Lake in their itinerary. That way you can not only spent a week diving the myriad of dive sites Palau is known for, but also visit its deservedly famous jellyfish lake.