Wednesday, January 21, 2009

Kakaban Lake Jellyfish


Kakaban Lake is located on the uninhabited island of Kakaban, which is part of the Derawan Island group in the Sulawesi sea. The lake was originally the lagoon of an atoll, formed by corals over a period of two million years. As a result of movements in the earth's crust the coral reef was raised above the sea level, trapping 5 km2 of seawater within a 50 meter high ridge, effectively creating a landlocked marine lake.

Where is Kakaban?

Lake Kakaban is located on the uninhabited island of Kakaban, which is part of the Derawan Island group in the Sulawesi sea. The lake was originally the lagoon of an atoll, formed by corals over a period of two million years. As a result of movements in the earth's crust the coral reef was raised above the sea level, trapping 5 km2 of seawater within a 50 meter high ridge, effectively creating a landlocked marine lake.

The lake is surrounded by a narrow mangrove belt and the entire island is covered with dense tropical vegetation. The coastline of Kakaban Island is encircled by a steeply sloping coral reef.

Why is Kakaban Lake unique?

The organisms found in the lake are originally seawater species such as marine algae, sea anemones, jellyfish, sponges, sea cucumbers, crabs, and several small fish species. Seawater, which seems to enter the lake through small cracks and crevices in the surrounding reef rock, is diluted with rain water, to produce a brackish water environment. Over thousands of years the inhabitants of the lake have adapted to their unusual environment. No large channels or connecting caves have been discovered, so no larger animals have been able to enter or leave the lake for thousands of years. Marine scientists are still trying to solve the mystery of how the isolated and fragile lake ecosystem supports the requirements of its plant and animal communities. Only one other similar lake ecosystem is known; it is found on Palau in Micronesia, about 1000 km east of the Philippines.

The plant and animal species of Kakaban Lake

About three species of the calcium carbonate-producing green alga, Halimeda, cover the bottom of the shallow areas of the lake. The roots of the surrounding mangrove belt provide a habitat for tunicates, sponges, tube worms, bivalves, crustaceans, sea anemones, sea cucumbers, several species of sea snakes, cardinal fish, and at least five known species of gobies. Four species of jellyfish (Cassiopeia ornata, Mastigias papua, Aurelia aurita and Tripedalia cystophora) are also found in Kakaban. Cassiopeia or the "Upside-down" jellyfish can be found lying on its back in shallow parts of the lake. This behavior exposes the jellyfish's symbiotic algae to the sunlight, and thus enable it to produce its food. A jellyfish-eating sea anemone is another interesting inhabitant of Kakaban Lake. This anemone has lost its symbiotic green algae, or zooxanthellae, so it appears white in color.

The benefits of eco-tourism

Kakaban Lake is a unique phenomenon and it attracts its share of eco-tourism. However, its tourism potential is relatively under-developed when compared with the situation in Palau. The 'Jellyfish Lakes' of Palau are visited by more than 30,000 people each year (this is double the population of the Palau islands). If Kakaban Lake could attract even 10 percent of this number of visitors, the revenue potential would be considerable. A visitor's fee of US$ 7.00 per person would bring in US$ 21,000 or 172 Million Rupiah per year. Transport, accommodation and other services would bring additional revenues.

Threats from tourism

While tourism offers opportunities for development in this remote area of Indonesia precautions must be taken to safeguard Kakaban Lake's unique environment. The dangers of unrestricted tourism are many: pollution, increased sedimentation and physical damage caused by the feet and hands of snorklers, habitat disturbances as a result of the use of outboard engines on the lake. An uncontrolled increase in visitor numbers without a code of conduct for sustainable tourism and without a zonation scheme for different lake areas is likely to result in physical damage, particularly in the shallow areas of the lake. Experiences in Palau show how fast such a negative impact can take place; excessive damage there led to a law forbidding the use of snorkeling fins in the lake. Recent tourism-related activities on Kakaban already provide several examples of such negative impacts:
Wood for planned cottages and 147 m of wooden walkways has apparently been cut in the Kakaban forest close to the lake.
Two boats, which will supposedly be powered by outboard engines, are being built on the island in order to take the tourists around the lake and to facilitate water supply of the resort.
According to unconfirmed reports up to 70 Hawksbill turtles have been released into the lake. They are no natural part of the lake ecosystem and may cause another threat for the fragile balance among the living organisms in the lake and to tourism, since the turtles feed on sponges and other invertebrates, which live attached to the mangrove roots and represent one of the major attractions for underwater photographers and snorklers.
The first signs of waste and litter can be found close to the walkway and in the "developed" area of the lake. The sewage and waste treatment of a proposed tourism facility would deserve special attention in order to avoid additional pollution of the lake.
An uncontrolled increase in visitor numbers without a sustainable code of conduct for sustainable tourism and without a zonation scheme for different lake areas will lead to a fast increase of physical damage to the unique animal and plant communities living in the shallow areas around the lake. Experiences made in Palau showed how fast such a negative impact can take place and led for example to a law against the use of snorkeling fins in the lake to decrease damage.

Solutions

With increasing tourist numbers, the potential negative impact on the lake ecosystem will become a major concern for the local government. In order to ensure sustainable use and long term profit, a well-implemented management plan for this national asset is of prior importance. If new tourism facilities are to be developed, an environmental impact assessment or "AMDAL" is of prior importance in order to determine likely impacts of resort development and construction.
Questions, such as carrying capacity, visitor quotas or zonation schemes may be addressed, before negative impacts become apparent.
A zoning plan would be an appropriate method to differentiate among areas, which may be allocated for tourism and tourism infrastructure, sustainable use by local communities, research and conservation.
The success of any management plan depends critically on the involvement of the local coastal communities, local NGOs, the private sector and scientists of Universitas Mulawarman in Samarinda in a multistakeholder planning process. The careful establishment of tourism facilities on the surrounding islands instead of on Kakaban and the development of a quota system for visitor numbers could ensure long term benefits to all stakeholders on regional, provincial, national and international levels

Kakaban lake Jellyfish

Kakaban Jellyfish