WATER POLITICS

The pier of Kampong Chhnang, a fishing community north of Phnom Penh, was alive at 7 a.m. with the rhythm of knives hitting chopping boards. Dozens of women sat on the ground, slicing flesh from fish reeled in by the men from Tonle Sap, Southeast Asia’s largest freshwater lake.

By noon, each woman would have about 20 kilograms to sell to fish paste makers, earning them just 10,000 riel, or $2.48. It was late October, two months early for the large-scale fishing season known as dai, but the men had cast their nets because the water was high from heavy rains, and the villagers could not risk it receding too soon.

At its fullest expanse, Tonle Sap used to swell every September to about the size of East Timor as rainwater flowed from the Mekong River. After the rainy season, water reverses in December from Tonle Sap back to the Mekong, pushing fish to a bottleneck at the southern end of the lake, where Kampong Chhnang sits.

Since ancient times, it has been a trusted source of fish and protein for most Cambodians, providing a livelihood for hundreds of thousands of fisher families among more than a million people who live by the lake. Tonle Sap had once been so bountiful that it gave rise to olden-day Cambodia’s great civilization, symbolized by Angkor Wat in Siem Reap at its northern tip.

Yet the lake, the beating heart of the lower Mekong River basin, is shrinking. Mekong watchers say global warming and the effects of hydropower dams built as far away as China are choking off the Mekong’s natural flow into Tonle Sap. Phnom Penh is struggling to produce enough cheap renewable energy to meet its development needs while protecting food security and the livelihoods of vulnerable communities.

Yields of Tonle Sap freshwater species like snakefish, whose mottled skin looks like that of a serpent, as well as catfish and carp, have nearly halved in a country where the U.N. says about half the population is vulnerable to food poverty. Fish caught in Tonle Sap account for about 60% to 70% of animal protein intake in the country, according to a 2023 study in the scientific journal Nature. But the Cambodian Fisheries Administration reported the catch from the annual dai fishing season sliding to 9,900 tonnes in 2020 from 16,975 tonnes in 2018.

Lifelong fishermen in Kampong Chhnang like Chuang Hai, 43, don’t need statistical reports to know things are changing.

He says conditions are now good for only 15 days a month during the December to February dai season.

He catches, at best, 100 kg of fish in a month, which he sells at $7 per kilo. Chuang Hai’s focus these days is simply feeding his family.

“If the water starts to come in June, then we can catch enough,” said Chuang Hai, speaking to Nikkei Asia in his floating home on the lake. “Because of the hydropower dam, the water comes slowly only in August.”

Scientists point to two reasons for the shortened flooding season at Tonle Sap: Climate change has disrupted rainfall; and dams like Lower Sesan 2, Cambodia’s largest, commissioned in 2018, have diverted Mekong waters into reservoirs.

The highest water level was lower in 2018 to 2020 than the average from 1997 to 2020. In 2020, the flooding lasted only 122 days, and covered an area less than half the historical average, according to WorldFish Center, a Malaysia-based research organization.

“We started to notice the slow coming of the water since the dam opened, especially these days when the lake water rises only because of the rain,” said fisherman Chuang Hai.

Tonle Sap fishing villages find themselves caught in Cambodia’s competing prerogatives. As the economy industrializes, electricity consumption is far outpacing domestic generation, and hydropower supplied 58% of the electricity generated in Cambodia as of 2022, according to the International Energy Agency. 

China and Laos, the region’s biggest proponents of hydropower, maintain that climate change has a bigger impact on the Mekong basin than the dams.

Scientists attribute delayed rainfall to climate change, but the water retained by dams along the Mekong rather than flowing downstream increased from 108 cubic kilometers in 2012 to 130 cu. km in 2021, according to WorldFish. That amount is more than three times the capacity of Hoover Dam.

New dam projects in Cambodia, on minor Mekong tributaries, and outside the country are underway. According to a 2019 Harvard University study, if all 11 dams planned on the main stream of the lower Mekong are built, fisheries production in the region would decline by 41%. 

While dams further upstream in China and Laos hold more than half the active water storage along the Mekong, Cambodia’s Lower Sesan 2 alone has resulted in 9.3% less fish in the lower Mekong basin, according to scientists at Princeton University, the WorldFish Center and the Fisheries Administration.

“Food scarcity at that scale is something that could plausibly cause social dislocation, political instability and conflict,” said Matthew Wheeler, senior analyst for Southeast Asia at International Crisis Group. “It’s calamitous that traditional livelihoods like fresh capture are dwindling, but there are alternatives. It’s just a matter of whether they can be scaled up to prevent the worst in terms of food scarcity,” Wheeler said.

Cambodian Prime Minister Hun Manet has called on authorities to ramp up fish farming as a way to tackle the drop in output. “The natural system cannot guarantee the supply of fish for consumption as it used to 30 or 40 years ago due to population growth, shallow rivers and lakes,” he said, in a speech to mark Cambodia’s official National Fish Day in July this year.

The fish day project is designed to “inspire a large fish farming movement across the country to ensure food security and consumption for the growing population,” Hun Manet said, according to extracts from the speech published on the website of Cambodia’s Office of the Council of Ministers.

When he succeeded his father as Cambodian leader last year, Hun Manet extended a moratorium on new dams along the main Mekong tributaries, enforced since 2020. Hun Sen had pledged to cut electricity rates after Lower Sesan 2 opened.

“Dam reservoirs do the opposite of what the river pulse needs to do — they release water during the dry season and store water during the wet season, which is ecologically disruptive,” said Brian Eyler, director of the Southeast Asia program at the Stimson Center in Washington. “It affects the migration of fish because it confuses them.”

Some dams along the Mekong have built fish ladders. structures that allow fish to pass over or around reservoirs. According to Eyler, the one at Lower Sesan 2 does not work: “Fish don’t know how to find the outlet, and it doesn’t account for different sizes of fish or the sheer volume of them.”

Nowadays, it takes two to three days for fishermen in Kampong Khleang, a Tonle Sap community two hours south of Siem Reap, to catch 50 kg of fish. Douen, the local fish paste dealer, needs 10 times that to make 80 kg of prahok fish paste, a protein staple for poor Cambodian households after the fishing season.

“This year the water has come very slowly, so the fish could not lay eggs on time,” said Douen, 53.

Food insecurity has increased in the past decade, despite Cambodia’s economic development.

Cambodia’s economy grew on average by 7.6% a year between 1995 and 2019, according to the World Bank, but contracted 3% in 2020 during the COVID-19 pandemic. It recovered to 3% growth in 2021 and 5.2% in 2022.

Still, 50.5% of Cambodians experienced mild to severe food insecurity on average in 2021 to 2023, according to the U.N. Food and Agriculture Organization. That was up from 48% in 2014 to 2016.

Cambodia expanded access to mains electricity from 16.6% of the population in 2000, to 82.5% in 2021, according to the World Bank. But large swathes of the country are prone to unreliable supply and frequent outages, even in tourist hotspots such as Siem Reap.

Rates are more expensive in Cambodia than its neighbors because of outdated transmission systems and the high cost of imported energy, which supplies 33% of Cambodia’s electricity needs.

“Electricity prices consistently rise. It has never gone down,” said Douen, the fish paste dealer in Kampong Khleang. His monthly bill can be as high as 100,000 riel, or about $25, he said, a steep price when the average household earned just above $380 each month in 2023.

Some families are turning to other ways of making a living. In six provinces around Tonle Sap, the number of fishing households has decreased by 10% from 295,678 in 2018 to 266,506 in 2019, according to a 2024 study by WorldFish Center.

In Phnom Penh, markets now offer farmed fish imported from Vietnam to the capital’s well-off urbanites — though Tonle Sap fishers aren’t convinced of its appeal.

“Snakefish from the farm is cheaper, but people prefer eating natural fish from the lake,” said Rodh, a fisherman in Kampong Phluk, a village on Tonle Sap an hour south of Siem Reap. “Farmed fish has too much fat.”

Because of Kampong Phluk’s proximity to Siem Reap, tourism has become an additional source of income there. For $5 a passenger, the women of the village take tourists to lakeside mangroves in brightly painted rowboats.

The men of the village fish while they can, before waters recede. By mid-November, the lake’s premature recession had left its high-water mark on the wooden stilts of their houses, which sit around a couple of meters above the ground.

During the dry season, villagers take up rice farming on land that used to be underwater.

In Kampong Phluk, fisherman Rodh stood under the noon sun, reeling in yards of fishing nets outside his stilted house where three families live. The older children helped pick small silver fish off the nets, while a younger boy watched over an infant sibling.

He fishes for five to six hours, but catches less than he did a year ago because the lake has not swelled as much. At the end of the day, he would earn less than $4 from 17 kg of fish.

“The price is not fair to us but we don’t have an option,” he said. “We don’t know what else we can do.”