Sarun Nong, a fisherman from Koh Krabey, a small island of Tonle Sap Lake in Cambodia, take another look at the fishing net in front of him. It contains only small fish, and too few to make ends meet.
âIn total, it’s maybe 3 or 4 kilos. I get 1000 riel [USD 0.25] per kilo, so I did not earn more than 4,000 riel [USD 1] last night, he said.
For fishermen like Sarun who depend on Tonle Sap Lake for their livelihood, almost every day this rainy season has been a disappointment. Just like last year and the year before, the lake’s water levels were much lower than they should have been during the height of the rainy season in October. For them, low water levels mean fewer fish migrating to their section of the lake and more challenges in growing crops, which depend on nutrients from flood water.
âWe have expenses for the fishing net and the boat. If it continues like this, we only lose more money, âSarun says, as her children scoop up some fish in the net.
Tonle Sap, the largest lake in Southeast Asia, has long been known as one of most productive fisheries in the world. But climate change, unsustainable and illegal fishing and the proliferation of hydroelectric dams on the rivers that feed the TonlÃ© Sap threaten livelihoods over a million Cambodians who depend on the lake. This year, things have been even worse than in previous years, with water levels about three meters lower than in 2018 in mid-October.
The Tonle Sap flood lifeline
With each rainy season, the flow of the Tonle Sap River in Cambodia is reversed. Monsoon rains increase water flow on the Mekong, Southeast Asia’s longest river that flows through China, Myanmar, Thailand, Laos, and Cambodia, where it meets the Tonle Sap River. Instead of flowing into the sea, the Tonle Sap River changes course during the rainy season. Then, Tonle Sap Lake functions as a massive basin for the Mekong River, extending up to six or seven times its dry season extent, inundating farmland and forests.
Through this process, agricultural land is fertilized and irrigated, while flooded forests provide ideal breeding grounds for fish that migrate from the Mekong to the lake in large numbers. At the end of the rainy season, in mid-November, the Tonle Sap river reverses again, and floodwaters flow into the Mekong Delta in Vietnam and the South China Sea.
But this year, much of the land has remained dry. âWe had the same situation last year. In the past, the land was always flooded. It’s very healthy for the soil if the water covers the land, âsays Yin Sela, a farmer who lives by the lake a few kilometers from Kampong Chhnang town.
Last year, Yin had to wait until November before the floods hit. He is concerned that the flooding will not occur at all this year. âIt really has an impact on my family. I can still grow a few crops without flooding, but the quantity will be less and the quality will be lower. And less harvest means less income.
Climate change and upstream dams threaten the Tonle Sap
Climate change, which causes longer droughts due to rapid evaporation and disrupted circulation patterns, has been at the forefront of Tonle Sap’s problems. Brian Eyler, of the US research institute Stimson Center, said rainfall over the past three years in the Mekong region, especially that which normally occurs during the rainy season, has been “unusually low”.
Another threat comes from hydroelectric dams. There are more than 100 hydroelectric dams in the Mekong and its tributaries, blocking water that would otherwise flow downstream.
âWe learned that 2020 was the lowest flow year for the Mekong over a 110-year data collection period. 2021 seems like a repeat of what happened last year, âsays Eyler.
Om Savath, Executive Director of the Fisheries Action Coalition Team, a Cambodian coalition of NGOs working on fishing and environmental issues around Tonle Sap Lake, points to similar causes. âThe rainy season and the rainy season have changed due to climate change, which is lowering water levels. And the hydroelectric dams upstream block a lot of water.
According to the Stimson Center, there is more than 100 hydroelectric dams on the main course of the Mekong and its tributaries, mainly in Laos and China. China, which does not regularly share operational data along with the downstream countries, has 11 active hydroelectric dams on the upper reaches of the Mekong, where it is known as the Lancang. There are two main operational dams on the Mekong River in Laos, upstream of Cambodia, and seven others at different stages of planning and development, most with at least the participation of Chinese companies in development or construction.
âWe have learned that the roadblocks [on the upstream Mekong] work the same in years of low flow as they do in years of heavy rainfall. Thisâ¦ worsens conditions downstream far more than these restrictions or discharges would impact the Mekong and Tonle Sap during years of heavy rainfall, âexplains Eyler.
Farmers and fishermen stayed dry
By the lake, areas of land and forest that should be underwater were still dry in mid-October. With each passing day, farmers and fishermen are losing hope that this will change this year.
In Trodouk, a village on an island in TonlÃ© Sap, village chief Yim Samol spoke with Le TroisiÃ¨me PÃ´le in his house. During a normal rainy season, his house and others in Trodouk, all built on high stilts, would be surrounded by water. But this year, the ground is still passable.
âBefore 2015, the water was still rising. It would be impossible to sit under the house. But now the water is getting lower and lower, âsays Yim. The forest near the village is no longer prone to flooding, which means that a local breeding ground for fish has been lost.
âAnd it’s not just the fish that are disappearing, there are also fewer other wildlife. We’ve always had big birds flying, but they don’t come here anymore, âYim says.
In addition to water levels, the ecology of the Mekong River system has been affected by upstream hydroelectric dams. According to the Mekong River Commission, only 16 percent sediment which settles in the lower Mekong basin, an important facet of the overall ecology of the river, now comes from China, up from 55 percent historically.
âThe Tonle Sap fishery will be shattered, as will Cambodia’s food security,â Eyler said. âThe Khmer diet relies on the freshwater fisheries of the Mekong for up to 70% of its animal protein intake. A Tonle Sap blackout will hit the wallets and stomachs of a large part of the Cambodian population. The Mekong River Commission warned in 2018 that the development of hydropower could result in biomass from fish stocks are declining from 40 to 80% by 2040.
Collaboration at the heart of solutions
In 2020, to address public concerns about the future of the Mekong, Cambodia released a 10-year moratorium on the construction of dams on the mainstream of the Mekong, essentially the suspension of projects at Stung Treng and Sambor until 2030. Last week, those plans were permanently suspended when the government announced it would abstain of any new hydroelectric project on the main stream. But the problems for TonlÃ© Sap Lake start further upstream.
âDams that have already been built must be exploited to restore more than a minimum of natural flow in the Mekong system. It is possible, although not ideal and cheap, to design this solution, âsays Eyler, referring to the use of dam operations to mimic natural flow. “Chinese dams will probably never be a part of this, so it will be up to the downstream countries to work together.”
Om Savath calls on the government to tackle climate change to help protect flooded forests to ensure fish can still reach their natural breeding grounds. âAnother important element is to patrol more to stop illegal fishing. If we can stop the illegal fishing activities, it will help the fish to grow. “
In Trodouk, Yim Samol thinks that agriculture will be the future of his villagers, instead of fishing. But only if farmers are sure that they are getting a fair price for their products. Farmer Yin Sela told The Third Pole that right now, for example, he only gets 200 Khmer riel ($ 0.05) for every 1 kilo of eggplant. âIf the expenses are low, we can have a good harvest here,â says Yim. “But if it continues like this, more and more people will leave because they can no longer make enough money in the village.”
âIf you have more water, you will have more fish,â Yim said. “But now it’s calm.”
This story was published with permission from The third pole.
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