Back From The Brink

One of Palau's many claims to marine fame has been its Jellyfish Lake, known locally as Ongeim'l Tketau. Palau has the largest collection of marine lakes found anywhere in the world. Just a few years ago, this famed body of water was thought to be doomed.

These isolated bodies of water have developed unique eco-systems. At Jellyfish Lake, millions of jellyfish live in a small area and snorkelers can swim with them. Due to the isolation, they have lost the need to sting prey and enemies. So snorkelers can swim with them, touch them and revel in their beauty, color and movements. The lakes have been the subjects of BBC documentaries and National Geographic Magazine feature articles.

Jellyfish Lake is a hike up and over a ridge deep in the Rock Islands. Once there, a plunge into the greenish water shows decaying vegetation mixing with a maze of roots. Blackbelted cardinalfish and other small fish dart through the waters. There are small, white anemones with flowing tentacles lining the roots. These are the only enemies the jellyfish have since they eat juvenile jellyfish.

To find the jellyfish, head for the sun. The animals have developed a relationship with algae. Basically, the plant gets its energy from the sun and the jellyfish from the algae. Thus, the jellyfish seeks the sunlight to keep the algae producing.

As the sun narrows across the lake in the afternoon, the jellyfish move closer together and the snorkeler can expect to be surrounded by hundreds of thousands of the animals at all depths. Diving down into this sea of pulsing, gelatinous umbrellas and looking back at the sun is a surreal experience.

This magical world became threatened during the 1997-'98 El Niño/La Niña event, when the world's coral reefs underwent dramatic change. Warm waters circulating the globe caused corals in some of the most exotic international locales to die. Some reef areas in the 100-mile-long Palau archipelago were damaged when this happened.

And people were shocked to find that, very quickly, the jellyfish in Jellyfish Lake were no more.

The lake's plight grabbed the attention of everyone from curious divers to affected tour agents to international marine biologists.

The jellyfish, or lack of jellyfish, became the project of biologists Laura E. Martin, Lori J. Bell, and Michael N. Dawson of Palau's highly respected Coral Reef Research Foundation in Koror.

The health of the inhabitants of Ongeim'l Tketau, and two other control lakes that aren't the haunt of tourists, became the subject of a study starting in December 1998.

So the biologists set about having a really good look at the life in the lake following El Niño. They surmise that the natural events at Jellyfish Lake killed all the sessile organisms living at certain depths including mussels, sponges, algae and jellyfish polyps.

The resulting study over the next few years shed new light on the health and recovery of the lake.

To everyone's relief, a steady recovery of the jellyfish population has taken place since their reappearance in December 1999. By December 2001, the lake contained a whopping 20-million jellyfish.

The team found that the disappearance and eventual recovery the jellyfish coincided with obvious and dramatic changes in the salinity, oxygen and temperature profiles of the lake.

For the casual snorkeler or diver, this is all good news. While being more closely monitored by Koror State rangers to ensure that the lake remains more natural, this amazing site is once again open to the public.