1. A Maninjau fish farmer beholds a carpet of floating carcasses after the mass death last week.
  2. The dead fish are carried out of the lake in plastic bags.
  3. Dead fish in Lake Maninjau.
  4. Farmers use nets to clean the lake.

Photos: Vinolia

Indonesia: First Toba, now Maninjau: another mass fish death hits an Indonesian lake
It was only the latest fish kill in the volcanic Lake Maninjau, which scientists say is overburdened with too many fish farms.
By Vinolia, translated by Philip Jacobson, 9th September 2016;

  • Three thousand tons of farmed fish are thought to have perished in Lake Maninjau, the largest lake in Indonesia’s West Sumatra province.
  • The die-off follows a similar incident that occurred in Lake Toba, North Sumatra, in May.
  • As in Toba, scientists say there are too many fish farms in Lake Maninjau, exacerbating the natural factors that may have killed the fish.

Another mass fish death has hit Indonesia’s main western island of Sumatra.

Four months after millions of Carp (Cyprinus carpio) and Tilapia (Oreochromis sp.) died suddenly in Lake Toba, the archipelagic country’s biggest lake, a similar incident has occurred in Lake Maninjau nearby.

The latter event is thought to have been twice as deadly. Where in May, 1,500 tons of fish rose lifeless to the surface of Lake Toba, fish farmers in Maninjau said that an estimated 3,000 tons appeared to have perished there on August 31 — and that the losses were financially ruinous.

The Maninjau die-off was also greater in scope. Where in Toba, the fish kill was limited to the floating cages of Haranggaol village, where locals had packed a sheltered bay with vast rows of steel-framed net pens, the Maninjau incident affected several villages around the lake. Toba is 11 times the size of Maninjau and 19 times the size of Manhattan.

The fish in Maninjau appear to have been either poisoned by hydrogen sulfide gas from hydrothermal vents on the lake floor or asphyxiated by a sudden depletion of oxygen in the water. This may have been brought on by an inversion of the lake’s water layers due to strong winds or rains — “extreme weather,” as local officials and fish farmers termed it.

But these natural phenomena are exacerbated by human activity, said environmental geologist Ade Edward Darwin. The first problem is that there are too many fish farms. The lake’s carrying capacity for aquaculture is 6,000 cages, according to the Indonesian Institute of Sciences (LIPI), a government-funded thinktank. At present, 17,000 cages now lie suspended in Maninjau’s waters. Uneaten fish feed and feces from the net pens fuel a process called eutrophication, in which the water becomes excessively rich in nutrients. This nutrient loading can induce oxygen-devouring algal blooms that suffocate fish, as is thought to have happened in Toba in May.

An added complication in the volcanic Lake Maninjau is that sulfur from hydrothermal vents can morph into hydrogen sulfide which poisons fish. Sulfur can also trigger the release of phosphorus from fish-feeding sediments in the lake’s bottom, fueling the eutrophication cycle.

Fish kills are a regular occurrence in Lake Maninjau. In 2009, 7,000 tons of fish turned up dead in the lake. Another major incident happened in 2014. Darwin, the environmental geologist, said the die-offs had been growing in frequency as fish farming expanded. In 2001, a LIPI team visited the lake at the request of the provincial governor and recommended a reduction in the number of cages on the lake. “This could not be implemented by the district government,” Darwin told Mongabay.

When Mongabay visited Maninjau after the latest fish kill, a foul odor hung over the lake. Masses of flies hovered above the stinking pens. The rotting carcasses had begun to mar the water quality. A team from the Agam district fisheries agency was helping residents clean up the lake, using vans and excavators to transport the dead fish. The carcasses were buried in empty fields on the lake’s edge.

Eriandi, a local aquafarmer, said he lost 50 tons of fish and put his losses at nearly 1 billion rupiah ($76,000). “If one kilogram of fish costs 19,000 rupiah [$1.44], one ton of dead fish means a loss of 19 million rupiah,” he said. “If 1,000 tons, that’s 19 billion rupiah [$14.4 million].”

Many of the fish farms are backed by entrepreneurs from outside the area, with farmers going in debt to fund their operations, said Ermanto, head of the Agam district fisheries agency.

“It’s difficult to get them to change their ways because they have multiplied their debts and they want to keep farming so that the debt is paid off,” Ermanto told Mongabay.

Another problem is that farmers tend to use fish feed that sinks instead of the more expensive floating kind.

“For every 10 kilograms of feed dropped into the water, only 6 kilograms at most are absorbed. The remainder accumulates in the lake,” Ermanto said.

Source: Mongabay

Indonesia: Sumatran Tiger rescued from Wild Boar snare in West Sumatra

27th May 2016;

A Sumatran Tiger (Panthera tigris sumatrae), which was trapped in a Wild Boar (Sus scrofa vittatus) snare in a hilly forest of Nagari Mandeh Village, West Sumatra, was rescued and evacuated by the local Natural Resource Conservation Agencys (BKSDAs) rescue team.

The team arrived in the area at 11:30 a.m. local time and managed to rescue the Tiger, which had been trapped since Tuesday (May 24), after making the big cat unconscious by shooting a tranquilizer dart, Head of Area III Conservation of West Sumatra BKSDA Surajiya stated here on Friday.

The Tiger would be brought to the Wildlife Cultural Kinantan Park in Bukittinggi District for rehabilitation.

“After undergoing rehabilitation, we will observe the Tiger’s recovery. If possible, we would return the Tiger to its habitat,” Surajiya affirmed.

Meanwhile, Chief of the Nagari Mandeh Village of Koto XI Tarusan Sub-district Jasril Rajo Basah expected the Tiger to be returned to its habitat near the village since the wild cat had not disturbed the day-to-day life of the villagers.

In fact, the village chief and local people acknowledged that the Tiger had several times helped the local people who had lost their way in the forest.

Moreover, the Tiger had become a natural predator of Wild Boars, which ravaged the peoples agricultural areas.

“We live side by side with the Tiger, therefore we hope the big cat will be returned here soon,” Basah added.

Source: Antara

Indonesia: Sumatran Tiger rescued from Wild Boar snare in West Sumatra

Photo: Aktual

Indonesia: Six tons of fish suffocate in Lake Maninjau
By Syofiardi Bachyul Jb, 21st February 2016;

About six tons of fish cultivated in keramba (net cages) were left floating on the surface of Lake Maninjau on Saturday; they are believed to have died of a lack of oxygen.

Agam regency Fisheries and Maritime Affairs Agency head Ermanto said the fish, weighing on average 4 kilograms each and cultivated in cages in an area adjacent to the villages of Bayur Maninjau and Duo Koto, had died suddenly and en masse on Friday.

“The cage owners were in fact already worried, as there had been no waves on the lake the day before. It’s a dangerous sign, because when the waters are calm, it can cause a lack of oxygen among the fish,” Ermanto said.

Some farmers removed the fish to inland ponds with sources of running water, but others ignored the warning signs, expecting to harvest the fish just two or three days later.

The fish required waves to bring oxygen, Ermanto went on, as the lake contained no oxygen between depths of 5 and 10 meters.

“Farmers have also been warned not to overfeed the surviving fish,” he said.

Mass deaths of fish in the lake have been a regular occurrence for 15 years, with overfarming generally blamed. Earlier in January, storms killed two tons of fish and destroyed many keramba, releasing a further 100 tons of fish. Last year, three separate incidents saw between 5 and 80 tons of fish die.

Currently, Ermanto said, there were 20,000 cages on the lake. A cage of 5 x 5 meters houses 4,000 small fish, and can produce 750 kilograms of fish per harvest. One cage of fish requires a ton of food per month.

“Every day, five or 10 new cages are added. Cage numbers are growing rapidly,” he said.

However, he added, it was not the absolute numbers of cages that was problematic, but their concentration in a certain part of the lake, while other areas remained empty.

“It’s tricky to redistribute the cages. We have to convince the local farmers and the cage owners, who mostly come from outside the area,” he explained.

The owners, who hail from North Sumatra, Riau and Bukittinggi in West Sumatra, hire local workers to man their keramba. However, as none of them hold business permits, the regency administration earns nothing from their business. The local authority’s attempts to curb the business, however, have been met with resistance from local residents.

Separately, fisheries expert Hafrijal Syandri of Bung Hatta University in Padang said the mass fish deaths were mainly down to pollution in the lake water caused by the remains of years’ worth of fish food.

Hafrijal, who frequently studies fish-farming on the lake, said almost 112 tons of food sediment left at the bottom of the lake since the large-scale fish farming began in 2001 had reduced the depth of the lake by an average 16 meters.

“The sediment turns poisonous and kills the fish,” he said.

The number of cages in the lake, he added, should ideally be capped at no more than 6,000.

Source: Jakarta Post

Unintended target: West Sumatra Natural Resources Conservation Agency (BKSDA) officers load a dead Tiger onto a truck for burial in the provincial capital of Padang, Monday. The adult 2 meter-long protected Sumatran Tiger was found dead on Saturday in a trap that local farmers set up for Wild Boars. Antara/BKSDA Sumbar

Indonesia: Sumatran Tiger found dead in wire trap
By Syofiardi Bachyul Jb, 5th May 2015;

A Sumatran Tiger (Panthera tigris sumatrae) has been found dead in a wire trap laid by a farmer in Pelangai Gadang village, Ranah Pesisir district, Pesisir Selatan regency, West Sumatra.

West Sumatra Natural Resources Conservation Agency (BKSDA) Region II section head Surajiwa said the farmer, named Darwin, 55, reported to the local police that a Tiger had been caught in his trap on May 2. The police then reported it to the BKSDA.

“Our officers inspected the location and found the Tiger already dead. We estimate it was trapped for two days. We have brought its carcass to Padang to be buried this morning,” Surajiwa told The Jakarta Post on Monday.

The female Tiger was estimated to be around 10-years-old. It died of wounds to its head and body. The location of the trap was around 2 kilometers from a village and 10 km from the Kerinci Seblat National Park (TNKS). The farmer had placed the trap for Wild Boars (Sus spp.) that often destroyed his chili and rubber farm.

“Based on information, he unintentionally trapped the animal, but we will send a joint team to the location again to further investigate the cause of death,” said Surajiwa.

The BKSDA has made efforts to secure the location and prevent the same incident from happening because based on a report from residents, an adult male Tiger and a Tiger cub were also roaming in the area. The Tigers have killed people’s livestock on several occasions.

TNKS Tiger protection and conservation field manager Dian Risdianto said although the dead Tiger was found as far as 10 km away, it would likely be from the TNKS.

According to Dian, the Tiger population was dwindling because of Tigers being trapped by poachers and farmers who placed traps. The current Tiger population in TNKS, spanning 1.37 million hectares, is 166.

“This is the latest data from the 2015 survey, by setting up cameras in various locations,” Dian told the Post on Monday.

In 2007, the Sumatran Tiger population across Sumatra was estimated at between 400 and 500.

Dian said the highest risks faced by the Tigers were traps, so TNKS Tiger protection and conservation conducted routine patrols to remove them. Each year, up to 40 active and inactive Tiger traps are found in the TNKS.

In the past five years, she added, three Tigers had been found dead by traps laid by farmers around TNKS, based on data from Pesisir Selatan, while four others were saved after being ensnared.

“We were able to arrest two poachers in Kerinci regency this year and another three in Sarolangun in February. We also seized a complete Tiger pelt and its bones,” said Dian.

She added that the Tigers were also threatened by habitat encroachment due to illegal logging and conversion as well as human-animal conflicts.

“With routine patrols, the Tiger population in TNKS could rise to 10 percent. However, members of the community must help by being careful with their traps and coordinating with the BKSDA and TNKS,” said Dian.

Source: Jakarta Post

Indonesia: Lake Maninjau and the Tragedy of the Commons

By Azis Khan, 17th April 2014;

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 of 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.

Source: Jakarta Globe

Indonesia: Lake Maninjau and the Tragedy of the Commons

Indonesia: Strong winds kill tons of Maninjau fish

By Syofiardi Bachyul Jb, 20th March 2014;

Hundreds of tons of fish, cultivated in floating net cages, or keramba, in Lake Maninjau, Agam regency, West Sumatra, have died following strong winds in the area.

“The strong winds have driven sediment, such as sulfur, fish feed and household garbage, to the surface, or upwelling. While on full stomachs, the fish were hit by high levels of ammonia, resulting in a lack of oxygen, which led to death,” Agam Regency Fisheries and Maritime Affairs Office head Ermanto said on Wednesday.

According to Ermanto, the phenomenon occurs almost every year, but the incident that killed tons of fish on March 13 was the first in the last three years.

“The phenomenon could occur in other locations due to recent weather, that’s why we have urged all keramba owners to immediately harvest their fish before the weather changes,” he said.

As of Wednesday, most of the 175.5 tons of dead fish had been left to float in the lake.

The dead fish were found in one of the dozens of locations in Lake Maninjau where keramba can be found — in Koto Malintang, Tanjung Raya district.

The Agam regency administration has asked the keramba owners to bury the dead fish.

“We have asked them to remove the dead fish because they are large-scale entrepreneurs who can afford to do so and they don’t have the permits to do business there. But as of Wednesday, only a few of them have done as asked,” he said.

The Agam regency administration, added Ermanto, had planned to take legal action against the entrepreneurs who failed to remove the dead fish.

The keramba, owned by 10 entrepreneurs from outside the area, are manned by local residents. The entrepreneurs were estimated to have incurred losses of at least Rp 3.5 billion (US$309,000), as the price of the Tilapia (Oreochromis sp.) and Carp (F. Cyprinidae) fish varieties could fetch Rp 20,000 per kilogram.

This is the third time such an incident has occurred this year. On Jan. 23 and 29, 11.5 tons and 10 tons of dead fish were found in the keramba, respectively. The presence of the keramba in Lake Maninjau has caused a serious problem in Agam regency. Currently, 15,000 keramba cages can be found in the 99.5 square- meter lake, producing 60 tons of fish, which are sold to Riau, Jambi and Bengkulu, while between 50 and 80 tons of feed are brought in from Medan, North Sumatra. The keramba owners, who hail from North Sumatra, Riau and Bukittinggi (West Sumatra), hire local workers to man their keramba. However, as none of them hold business permits, the regency administration earns nothing from their business. Local authorities, however, have been met with resistance from local residents during attempts to curb business.

Source: Jakarta Post

Indonesia: Strong winds kill tons of Maninjau fish

Easiest catch of the day: Thousands of dead fish float to the top of volcanic Indonesian lake after being poisoned by sulphur stirred up by storms
Mass death is apparently caused by a sudden change of weather conditions, according to fishery officials
Same scene in 2009 when at least 7,000 tonnes of fish died from poisonous sulphur stirred up from the lake bottom
By Jill Reilly, 18th March 2014;

Thousands of floating dead fish have bizarrely appeared on the top of a scenic lake in Indonesia.

The mass death of the fish in Maninjau lake, West Sumatra province, is apparently caused by a sudden change of weather conditions, according to fishery officials.

It is not the first time locals have seen the unusual phenomenon – at least 7,000 tonnes of fish bred in floating fish farms at the lake died from poisonous sulphur and fish-feeding sediments stirred up from the lake bottom by storms in 2009.

At the time the West Sumatra Maritime Affairs and Fisheries Agency said the mass deaths were caused by an upwelling, with sulphur-rich colder water from the bottom rising to the surface due to a drastic weather change.

They said the fish perished from sulphur poisoning and they also detected a small amount of ammonia, ‘which is not supposed to exist under normal conditions.’

The 99.5-square-kilometer Maninjau is a volcanic crater lake in Agam district.

The lake, which has a depth of close to 500 metres, is known for its mountain-rimmed panorama and has become one of West Sumatra’s famous tourist destinations.

Source: The Daily Mail