When green isn’t clean
Two years ago the fish farmers of Kakas in the Minahasa highlands of North Sulawesi gave up their fight. To stay in business they had to shift a further 150 meters into clearer water and abandon their shoreline investments.
“What else could we do?” said Petrus Lamongi (above) whose family raises goldfish. “We’ve tried most things but with no success. It’s such a huge problem.”
No scientific knowledge is required to understand this story of gross aquatic damage, reported to be among the most severe in Indonesia. There’ll be no dispute about the facts, no sceptics to neuter concerns, as in the global warming debate.
Microscopes aren’t needed. Just a squint for a second is proof enough.
Lake Tondano, the once splendid sparkling center of the Republic’s most northern province, is being garrotted. The noose circling its banks is lush green and pretty pink, seductively enchanting, but eceng gondok is a rapacious coloniser and ruthless killer.
Elsewhere it’s known as a type of water hyacinth. It came from the Amazon Basin and was exported as a decorative pond plant. Then it escaped to become the world’s most invasive plant.
Whoever dropped a runner in Lake Tondano about 20 years ago should be tried for corrupting the environment.
The free floating perennial isn’t the only threat to the 4,300 hectare freshwater lake in the caldera of an ancient volcano, 600 meters above sea level. Nutrients from surrounding paddy and sediment from the clear-felled hills are also doing awful damage.
In 1934 Dutch engineers measured the lake’s depth at an average 40 meters. Forty years later it was 28 meters and two years ago just 12, according to the North Sulawesi Environmental Management Agency.
If it was just another tourist attraction then the harm would be limited. But Lake Tondano is ‘the heart of North Sulawesi, representing the source of water supply for a large proportion of the population,’ according to a report by international consultants Mott MacDonald.
‘It is also a source of water for gravity irrigation of crops - mainly rice… it’s the center of cage-reared fish of northern Sulawesi. Equally important is its role in electric energy in a cascade of dams under the lake.’
Between 2003 and 2005 the lake and its surrounds were mapped and researched. About a third of the watershed was identified at risk.
Areas of land were replanted with around 10,000 trees. Erosion banks were installed in 21 demonstration plots that included crop rotation to reduce runoff.
The long term aim was to help lift incomes and living standards for the people who rely on the lake for food and irrigation. The Minahasa Region, centered on Tondano town, has a population of more than 300,000.
Suitably impressed the Czech Republic began funding a five-year US $415,000 (Rp 4.3 billion) rehabilitation project through its development agency in association with the Minahasa Regency. That was in late 2008 – and it couldn’t have started at a worse time.
The global economic crisis hit Europe and within two years the funds had vanished. But not the weed. Locals had dragged some of the huge green carpets ashore to dry but the task is Herculean. Enthusiasm wilted when the cash flow stopped.
Small sheds were erected on the lakeside housing engine-powered shredders so the dried nitrogen-rich material could be processed into fertiliser.
The machines stand idle, quietly rusting while the wind-whipped weed laughs its way to the further bank, dropping seeds that can last up to 30 years. Rabbits are supposed to be prolific, but eceng gondok can double its population in just over a month.
Despite its criminal record, that includes harboring mosquitoes and starving the lake’s nike fish of oxygen, the weed has some redeeming qualities. It sucks up heavy metals including arsenic so can purify polluted water, particularly from industrial sites.
The dried stems are strong, particularly when braided into ropes. Woven through wood or bamboo slats it makes robust chairs and sofas, though manufacturers say the gray material is too waxy to take paint or varnish. It can also be used to make paper.
“The main aim was to bring new cropping patterns that would benefit farmers and also introduce crops for production of bio fuels,” said the former project manager Dr Karel Peter Kucera.
“There’s a shortage of fuels for transportation and cooking, so farmers have started to cut the trees again. Bio fuels could be used to address this situation.
“We identified about 15,000 hectares that could be used to establish agroforestry plantations. We also recommended harvesting the eceng gondok and use it for production of organic fertiliser, bio gas and furniture.”
In 2011 the Environment Ministry launched a Lake Rescue Plan (GERMADAN) to save 15 lakes, including Tondano. It is understood most attention is being given to Lake Kerinci in Central Sumatra and Lake Rawapening in Central Java.
This year nine ministries signed an agreement for ‘sustainable management’ of the lakes. No budget was announced.
An Environment Ministry officer said regional governments had to do more to protect their lakes. In Tondano’s case allowing the spread of fish farms was aggravating the problem becaus feed and excrement encouraged weed growth.
In April this year North Sulawesi, Governor Sinyo Sarudajang told Antara News that he was committed to handling the problem. German experts would visit the lake “soon” and see if the weed could be used to make bio-gas.
However his staff said it was not known when the German team would arrive. A circuit of the lake found no sign of control measures, and villagers claimed nothing was being done to halt the invader.
Indonesia isn’t the only victim of eceng gondok, but it seems to be one of the most passive. Elsewhere a war is being waged with machines, chemical sprays and insects, though all have their downsides. An infestation in Florida is now reported to be under control.
“The lake should be saved,” said Dr Kucera, “but it needs a good feasibility study and I think honest international and local investors.”
First published in The Sunday Post 8 September 20130