Preserving Indonesia's lakes requires adequate research

By Badruddin Machbub and Pasi Lehmusluoto

JAKARTA (JP): Indonesia is home to a unique collection of more than 500 tropical lakes, in addition to 100 reservoirs. Of this total, the condition of the economically and nationally important lakes has been practically unknown, until recently.

The important lakes are located in Sumatra, Bali, Sulawesi and Irian Jaya. In addition, there are a few important or special lakes in Java, Kalimantan, Lombok and Flores.

No national-level studies were conducted on Indonesian lakes until the Indonesian-Finnish Indodanau expedition commenced its work in 1991, making a systematic five-year survey of 38 lakes in Indonesia, covering the areas from Sumatra to Irian Jaya.

Over the last few decades, various authorities have also conducted sporadic studies on some of the lakes, but no consistent data is available to monitor the development of the lakes' condition.

During the Indodanau expedition, studies were conducted on many of the lakes at great depths, even down to 500 meters, and in many cases, for the first time.

Indonesia's lakes are generally in good condition. This is partly due to the fact that the drainage areas are small and isolated. The lake chains are more problematic, since their drainage areas are larger, and agricultural and industrial activity, as well as population centers near these lakes could result in considerable pollution.

The capacity of the Indonesian lakes against chemical and nutrient absorption is relatively weak not only because of the chemical quality of water, but especially because of the long residence times of lake water. The water is very slowly renewed.

Surface water temperatures varied from 21.4 to 30.8 centigrade, depending on the depth. The vertical temperature difference was at its greatest 3.9 centigrade, and at its smallest 0.2 centigrade.

Generally, the deep waters are anoxic, with a few exceptions, such as Lake Toba. In some of the lakes, hydrogen sulfide was also found. The oxygenated water volume of Singkarak Lake was only 15 percent of the total volume.

The nutrient concentrations were unusually low, and the chlorophyll concentrations expressing the amount of algae in water showed that the lakes were unproductive.

Indodanau's research project resulted in information on the major and economically important Indonesian lakes in terms of evaluating their present state and for planning their future monitoring and studies. However, for the sustainable utilization of the lakes, specific action plans will be prepared. Otherwise, there is a danger that the systematic studies already commenced may become fortuitous -- and lakes polluted and eutrophic.

Environmental policy

Indodanau's lake research project, like other research projects, has the responsibility to influence the government's environmental policy. Despite the need to relate research to the policy, there is no existing mechanism or framework to assure that research results are always available to policymakers.

In Indonesia, lake research may not be a major influence on lake environment policy with respect to pollution, eutrophication and to fisheries management. Despite this, it must be recognized that research is not always regarded as a necessity for environmental management, and is often regarded as a hindrance. Research is, without justification, becoming synonymous with delay tactics to avoid addressing problems.

Currently, lake environment research in Indonesia tends to be reactionary. Environmental management, if not crisis driven, is definitely issue driven. This is not necessarily a problem for the research community, until there is confusion between studies to collect data and the research process. There is already concern over programs being data-rich and information-poor.

As fewer and fewer resources are spent on studying the physical, chemical, and biological processes, we will drift further from understanding lake systems and their capacity to sustain communities that surround the shorelines. Essentially, to address small, specific questions, we will have lost sight of the ultimate goal of environmental management.

We need to develop core research programs for Indonesia's lakes, programs that are long-term and provide a balance between basic and applied research. We need to convince policymakers that such programs are essential for sustainable development. We must obtain knowledge about the natural systems before we can define their capacity for development. To live within the limits of lake ecosystems means that we must devote a considerable effort to system level research.

The low profile of environmental research leads to the concern that it is not really gaining support, despite the global awareness illustrated at the Earth Summit in Rio de Janeiro in 1992. There are no large ecological/environmental lake research programs that compare large areas or continents, such as the Indodanau expedition in Indonesia. Many other research fields are attractive because of the possible expectations of future payback, but environmental research has great and relevant returns, although not always readily quantifiable.

Based on the Indodanau expedition, a continuous lake research process shall be carried out for each lake in Indonesia. As studies have shown, more people have died from drinking polluted and microbial contaminated water than from the indirect effects of global warming or changes in biodiversity. However, only limited financial resources have been devoted to solving environmental problems. It is our responsibility to make certain that Indonesian lakes remain healthy as future important sources of water, that they maintain their productivity for food supply, and that the research conducted on the lakes is credible.

Dr. Badruddin Machbub is Indonesian supervisor and Limnologist Pasi Lehmusluoto is the project coordinator of the joint Indonesian-Finnish Expedition Indodanau. Pasi Lehmusluoto has participated in the development of Indonesian lake resources since 1974.