Azis Khan Jakarta Globe 17 Apr 14;
Lake Maninjau, the 11th-largest in Indonesia, lies about 460 meters above sea level in the Tanjung Raya subdistrict of Agam in West Sumatra. It has a surface area of almost 100 square kilometers and a water catchment area of almost 25,000 hectares. Sadly, it is one of 15 lakes in Indonesia that are severely degraded, which has a serious impact on the lives of communities surrounding it.
Almost every year, fish die in the lake on a large scale, and biodiversity is declining along with water quality.
At the same time, the panoramic lake is becoming increasingly unattractive as a tourist destination because of the many floating net cages belonging to the people living in the lake’s surroundings.
Large-scale fish deaths
As reported by VIVAnews last month, the mass of fish dying prematurely in one such incident reached at least 175 tons, with total losses amounting to Rp 3.5 billion ($307,000). This was already the third such incident this year. Similar incidents have occurred in previous years.
One theory is that the mass fish deaths are caused by changes in the bottom of the lake, with sulfur being lifted to the surface during volcanic activity, as the lake sits in a massive caldera. But another suggestion is that the lake’s bottom layer is polluted due to highly concentrated ammonia from fish feed sludge and household waste, which is occasionally lifted to the surface due to wind-driven turnover.
Proponents of this theory say sulfur should be ruled out as a cause because there is no indication volcanic activity in the lake, suggesting that the mass fish deaths are far more likely to be caused by environmental damage related to human activity in the area.
A study done by the Indonesian Institute of Sciences (LIPI) and the Bandung Institute of Technology (ITB) some time ago, found that the environmental damage was most likely caused by the large number of aquaculture cages used in the lake. This study suggested that the lake would be able to sustain just 10 percent of floating net cages currently in use.
So, in 2011, when the number of cages exceeded 15,000, just 1,500 would have been a more sustainable figure.
But it’s not just the number of cages that poses a problem. Their positioning is another major issue. The head of the local Marine and Fisheries Office has long ago stated that the fishermen must place cages at least 200 meters from the lake’s shore, at a depth of 15 meters. The distance between cages should be at least 10 meters, the office ruled.
Despite the ruling, as recently as 2012 cages were located just 50 meters from the shoreline, at shallow depths of five meters, with the distance between them being only a meter. The marine and fisheries head said that almost every year copies of his regulation are distributed, but most people seem to disregard it.
Tragedy of the commons
The problems at Lake Maninjau bring to mind Garrett Hardin’s thesis of the Tragedy of the Commons (TOC). Understanding the concept of TOC is very important in tackling environmental challenges. This concept was first clearly articulated by Hardin in his now famous article of the same title in the journal Science in 1968.
The basic idea is that when a resource is held in common to be used by all, and left unregulated, then the resource will eventually be destroyed. In other words: “Freedom in a common brings ruin to all.”
Could this happen to Lake Maninjau?
If we compare the situation at the lake with that of a commonly held pasture used by several goat farmers, an example used by Hardin, we would expect that every fisherman would try to install as many floating net cages as possible to maximize individual gain — just like goat herders would try to let as many animals as possible graze on the pasture.
In this scenario, sooner or later the gains per cage will decline due to the increasing number of cages used by others in the lake. When the total number of cages is still within the natural capacity of the lake, then any increase in the number of cages will mean farmers’ incomes will fall as the available resource has to be shared by more people. Such a situation will continue until the limit of the natural ability of the lake to sustain cage nets is reached.
When that happens, the resource available will decline in absolute terms, with all farmers suffering losses. And ultimately, when the lake’s ecosystem is completely destroyed — as evidenced by mass fish deaths for instance — there is nothing left to share.
All in it together
The main lesson we should learn from the concept of TOC is that natural resources, such as clean water in the case of Lake Maninjau, cannot be exploited without limit and that technological innovation is no panacea. To solve the tragedy of Lake Maninjau, what is required is a fundamental change in human values and our and ideas of morality.
In short, the fishing communities around the lake all need agree to work together to preserve the lake’s resource and, if necessary to force one another to comply with regulations drawn up for the common good. Mutual coercion will be essential.
As Hardin himself argued, and as echoed by Jared Diamond in his 2005 book “Collapse: How Societies Choose to Fail or Succeed,” tragedy is not inevitable, as long as people manage to impose restrictions to ensure the economic sustainability of the community. In the case of Lake Maninjau, the arrangement could include agreements to ensure the lake is designated for the purposes of tourism, hydro-electric power generation, fish farming or a combination of these. Whichever solution is found, it will be crucial that the people living in the lake’s surrounding areas collectively agree.
Local authorities may play an important role, as they understand the current conditions at the lake and the needs of the communities it sustains. If nothing is done, complete destruction of Lake Maninjau is only a matter of time.
Azis Khan is a freelance writer who specializes in natural resource management and policy analysis.
