Snorkelling in Jellyfish lake is perhaps like no other experience. Every day, millions of jellyfish migrate around this lake. Furthermore, they have lost their ability to effectively sting and are totally harmless to snorkelers and swimmers. Jellyfish Lake snorkelling is a once in a lifetime opportunity.
Jellyfish lake is a snorkel site in Palau on Eil Malik Island. It forms part of the Rock Islands, a group of small and largely uninhabited in Palauís southern lagoon. The basin became filled by marine water as a result of melting ice raising sea levels, some 12 000 years ago.
A pass will be necessary to go snorkelling in the lake, and once purchased, lasts for 10 days. It is also not permissible to scuba dive in Jellyfish lake, as exhaust gas bubbling upwards can damage the delicate jellyfish. Beyond a depth of 50 feet (15 m), where the anoxic layer begins, hydrogen sulphide is found in considerably high concentrations. It can be absorbed through the skin, easily diffusing through any exposure suit, where toxic levels can build. It has also been recorded that at shallower depths, above the anoxic layer, there is 0 hydrogen sulphide.
Marine life in Jellyfish Lake
The lake is very isolated, with only very limited access to the sea via several small tunnels that appear near the surface of the lake. The isolation has greatly reduced the species diversity over time, helping to remove any natural predators of the jellyfish. As a result, the jellyfish have evolved to almost entirely lose their ability to sting. It is so minor, that the vast majority who go snorkelling cannot feel it, and only a handful with highly sensitive skin have noted small discomfort.
There are two jellyfish species, the golden jellyfish and the moon jellyfish. The golden jellyfish is closely related to the spotted jellyfish that is found in nearby lagoons. However, golden jellyfish also exhibit strong differences in their structure, function and behaviour. They also lack spots, and have almost completely lost their clubs.
Moon jellyfish are translucent, and larger in diameter, usually between 10 and 16 inches wide. They are easily recognisable when snorkelling by four horseshoe-shaped gonads, usually painted a vibrant colour.
Every day, millions of golden jellyfish migrate horizontally across the lake. Their journey begins at daybreak when they move from the centre of the western basin, to the centre of the eastern basin, usually completing their journey by 9:30 in the morning. Then, from midday until 15:30, the golden jellyfish embark on their second daily migration, heading to the western end of the lake. It has been noted that as they migrate, they rotate anti-clockwise. It is believed that by doing so, the jellyfish can expose the algae that live symbiotically within their body to energy providing sunlight. Finally, during the night for approximately 14 hours, the jellyfish move vertically in the water column, possibly to obtain nutrients.
Moon jellyfish do not have such a structured migration pattern, and seem barely capable of any significant motion. At night though, they move towards the surface of the water where it is thought that they feed on the copepods (groups of small crustaceans) that also surface during the night.
Best time to snorkel in Jellyfish Lake
Palau features a tropical climate, with fairly heavy rainfall throughout the year. The rain is short-lived though, and most of the day is beautifully sunny. The heaviest rains fall between July and October and do reduce the visibility to around 50 to 80 feet (15 to 25 m) from 100 to 130 feet (30 to 40 m). It is possible to visit all year around, but the best time to go on your snorkel trip to Jellyfish Lake is between November and May, when conditions are at their calmest. Water temperatures remain at around 84 Fahrenheit (29∞C) during the year, dipping slightly to 79 Fahrenheit (26∞C) in March.
How do I get to Jellyfish Lake
Palau international airport provides direct international flights with Tokyo-Narita, Taipei, Manila and Seoul, facilitating a fairly straightforward journey to your snorkel tour in Palau. Most citizens can visit for up to 90 days as a tourist without previously applying for a visa, while certain citizens, such as US citizens, can enter for up to year. As with any international travel, ensure you check any immigration requirements well in advance of your intended date of travel to avoid any inconvenience.