The Jellyfish Lake in Palau make it to one of the most unique tourist destinations in Micronesia. This marine lake on the Rock Islands hosts thousands of golden jellyfish and after being closed for a while, this special place is open again waiting for visitors who wish to experience swimming with these wonderful golden creatures!
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Where is the Jellyfish Lake?
The Jellyfish Lake can be found on the uninhabited Eil Malk Island off the coast of Koror in Palau. To get to the lake, visitors need to take an approx. 45 minutes boat ride from Koror. Expect paying an entrance fee. The Eil Malk Island (originally called Ongeim’l Tketau) is part of the Rock Islands, a group of small islands between Koror and Peleliu.
On these rocky islands, there are more than 50 marine lakes that are connected to the ocean through several tunnels and fissures. The Jellyfish Lake in Palau is one of these special marine lakes, which thanks to its location and geographical characteristics hosts a large population of jellyfish.
Is the Jellyfish Lake open?
Palau government decided to close the lake in 2016 due to dramatic decrease of the jellyfish population, but luckily, the recovery process was successful and the Jellyfish Lake in Palau is open again! According to the official statement of the Ministry of Natural Resources, Environment and Tourism in Palau, the significant decrease happened due to drought conditions. The closure was necessary in order to create ideal conditions for the lake’s Golden Jellyfish population to recover.
The process was monitored by the Coral Reef Research Foundation who confirmed that after a rainier than average season, the jellyfish returned so the government re-opened the Palau Jellyfish Lake in December 2018. The 2016 closure was the second time when the government decide to close the lake. The first incident happened in 1998 when the jellyfish population declined to zero due to climate changes. The reason behind this event was the rising sea temperate that killed the symbiotic algae that live within the jellyfish. In the first case, the population recovered by 2000 when the area was re-opened.
How can jellyfish live in a lake?
Although there are freshwater and saltwater jellyfish, the species living in the lake belong to the saltwater species. The Jellyfish Lake in Palau is a 12.000 years old stratified lake which means there is no oxygen in the deeper layers but high concentration of hydrogen sulfide. Therefore, the inhabitants can live in the upper oxygenated layer only that begins at 12-14 m (40-45 ft).
This upper layer is oxygenated with persistent stratification. Mixing of the layers vertically does not occur due to some simple reasons:
- thanks to the tropical climate the seasonal temperature variation is small so there is no temperature inversion that could cause vertical mixing
- the surrounding big rocks and trees block the wind
- the primary water sources are close to the surface so there are currents only in the upper layers
The lake is connected to the sea via 3 tunnels. Through these 3 tunnels the tidal water flows in and out. About 2,5 % of the lake’s water is exchanged during tidal flows, but only in the upper layer.
What type of jellyfish are in the Jellyfish Lake Palau?
The majority are Golden Jellyfish, but also Moon Jellyfish live in the Palau Jellyfish Lake. The Moon Jellyfish are less common. They are transparent “lazy jellies” that don’t move so much and spend the daylight hours feeding on plankton below the surface in the depth of 5 m (15 ft).
The Golden Jellyfish are more active and there are thousands of them! The golden species constantly migrate across the lake by following the sun. Every morning around 6 o’clock they start to move with the sunlight from the west to east and then back in the afternoon. This migration happens because they must stay out of the shadow to avoid capturing by the predatory sea anemone.
Are these jellyfish dangerous?
Despite their size (15 cm/5,5 in) you can safely touch the Golden Jellies because they are harmless. The local myth tells that they have lost their stringers because they are living isolated in a predator-free lake for a long time. The truth is that they have stingers, but these are too small to be felt by humans. You may feel slight tingling if you have a sensitive skin, but don’t worry because they are not dangerous!
Although these species are not dangerous, for your own safety read how to treat a Jellyfish sting
Can you swim in the Jellyfish Lake?
The Jellyfish Lake is currently the only marine lake on Palau where tourist can swim. The other marine lakes on the Rock Islands remain closed for visitors in order to preserve them.
There are some rules and advice that you need to follow for your own safety:
- The anoxic layer of the lake contains high concentrations of phosphate and ammonia. These might be dangerous and can cause skin irritation, therefore diving is not allowed only snorkeling! People with sensitive skin are suggested to wear protecting clothes. Do not dive, always swim in the upper layer
- The best is to wear fins during snorkeling to maintain greater control. Swim slowly in a prone position and try not to kick strongly as you could rip or tear the jellyfish
- Do not apply sunscreen before entering the water and check that your equipment is clear
If you follow these suggestions and rule, you will contribute to preserve the lake so the next generations can enjoy its beauty too!