Indonesians race to save their disappearing lakes, before it’s too late

Seventeen lakes in the Southeast Asian nation are in “critical” condition. One of them, Lake Limboto in northern Sulawesi, is shrinking rapidly and could disappear by 2025.

Anton Kui has fished here since he was in fifth grade. He remembers he could quickly catch a day’s worth of fish close to his home.

That was the 1970s, when this lake in Gorontalo province, on the Indonesian island of Sulawesi, was twice the breadth and almost three times the depth it is today.

“Now, a full day does not guarantee even 10 fish,” said Kui, who heads a small local fishermen’s association, Citra Neyalan. “Only the lucky ones get more.”

In addition to the fishing community, the lake supports a budding tourism industry and almost 50 species of transcontinental migratory birds that travel annually from Siberia to Australia.

But deforestation in the mountains around Lake Limboto is filling it with millions of tons of sediment every year, raising the lakebed and increasing the risk of flooding in surrounding areas. That’s the biggest reason researchers now predict the lake will cease to exist by 2025.

The problems plaguing Lake Limboto are not unique to Gorontalo. Seventeen of Indonesia’s lakes are classified as being in “critical” condition, meaning they suffer a host of environmental problems, chief among them sedimentation that causes shrinking.

After decades of inaction at Limboto, efforts to save not only this lake but others like it are racing ahead.

Two months ago, government officials and academics from across the archipelago country gathered on Limboto’s shores to find a solution for Indonesia’s critically endangered lakes.

They declared to Jakarta that a national body should be created to direct attention and funds to the nation’s more than 800 lakes.

The declaration was heard. A delegation of district chiefs and academics from seven provinces met with the Regional Representatives Council, one of two houses in the nation’s bicameral parliament, in the capital last month, and they will meet again in December to discuss the possibility and details of a national institution to oversee the issue.

The delegation hopes its discussion will result in a final meeting with President Joko “Jokowi” Widodo to create the tentatively named Forum Daerah Peduli Danau Nusantara, or the Archipelago Lakes Regional Forum. Nelson Pomalingo, the head of Gorontalo district, said in an interview that the institution’s purpose would extend beyond his jurisdiction.

“We aren’t just talking about Lake Limboto — we are talking about all lakes in Indonesia,” said Pomalingo, who is also a professor of agriculture.

“Until now, we were just discussing among the district chiefs, but now we are bringing it to the national level.”

Because of this higher sedimentation in the lake, we can’t afford to have rain anymore. There are floods every rain during the rainy season.

Dony Lahati, head, public works department

Shrinking lakes

Lake Limboto is an example of what is happening to other critical lakes in Indonesia, Pomalingo said, as deforestation and aquatic weeds accelerate the draining of the lake, threatening the local economy and wildlife.

In 1932, the lake spanned 70 square kilometers (27 square miles) and had a depth of 30 meters (98 feet). By 1970, it had shrunk to 50 square kilometers and 8 meters deep. Today, the lake measures just 25 square kilometers and is only 3 or 4 meters deep.

Government-subsidized corn farmers in the mountains surrounding the lake frequently clear forest, but don’t return to a plot of land after it has been used, said Hasim, a professor who will join the delegation in December and uses only one name. Twenty-three rivers carry soil into the lake from nine subdistricts and 70 villages.

Invasive water hyacinths also cover much of the lake’s surface. Kui, the fishermen’s association chief, noted that water hyacinths the size of a small table could grow to fill a room in a matter of weeks.

In addition to dumping more material on the lake floor, the free-floating plants accelerate the evaporation of water and decrease the amount of oxygen in the water. During the 2012 dry season, researchers found that water hyacinths had spread across 51 per cent of the lake’s surface. Government estimates put that figure even higher.

But some fishermen propagate the water hyacinths to attract the fish that are becoming harder and harder to find, and the government is having trouble stemming the practice.

“Our goal is to decrease the area occupied by the water hyacinth, but we have to work with the fishermen,” said Bambang Supriyanto, secretary of the district’s planning agency. “To change their habits, we need strong efforts, including education about how to use the water hyacinth.”

The government’s biggest fear, however, is the flooding that increasingly threatens nearby Gorontalo city. The lake came into being as a flood-inundation basin, meaning if it disappears, rainwater must find somewhere else to go.

“Because of this higher sedimentation in the lake, we can’t afford to have rain anymore. There are floods every rain during the rainy season,” said Dony Lahati, head of the public works department in the district. There is only one outlet from the lake into the sea, managed by a dam.

Humans are not the only species affected. Rosyid Azhar, a photographer, spent one day a week monitoring birds at the lake during this year’s migration season. He’s seen birds from the Arctic and Australia stop at this equatorial lake. Normally 85 species live here, 49 of them migratory.

“This year, not as many birds came to the lake as in past years, neither the number of individual birds nor the total number of species,” Rosyid said. More research was needed to understand why, he added, but it was already clear the government’s project to dredge the lake was disturbing the traditional habitat, possibly deterring birds from stopping at Limboto.

“The government is trying to clean up the water hyacinths but they throw away all the vegetation,” said Pantiati, biodiversity officer with Burung Indonesia, the local affiliate of Birdlife International, an NGO. “And now if you see the lake … just water and water.”

The government says the solution must make use of “local wisdom” such as simpler fishing methods, raised homes that “respect” the lake, and ways to make use of plants in the lake.

The other lakes in “critical” condition include Lake Toba in North Sumatra, Lake Rawa Pening in Central Java, and Lake Jempang in East Kalimantan.

This story was published with permission from Mongabay.com. Read the full story.

Thanks for reading to the end of this story!

We would be grateful if you would consider joining as a member of The EB Circle. This helps to keep our stories and resources free for all, and it also supports independent journalism dedicated to sustainable development. It only costs as little as S$5 a month, and you would be helping to make a big difference.

Find out more and join The EB Circle

Advertisement
blog comments powered by Disqus
Advertisement

Most popular

View all news

Industry Spotlight

View all

Feature Series

View all
Asia Pacific’s Hub For Collaboration On Sustainable Development
An Eco-Business initiative
The SDG Co