Talk to a fisherman anywhere in the world and it won’t be long before you’ll hear the tales: the first catch, the one that got away, the really big one. On Tonle Sap Lake, the largest body of freshwater in Southeast Asia, the fish stories are divided into then and now.

The old stories go like this: In 1992, Yem Yun caught a 220-pound Mekong giant Catfish. How big was it? So big, his boat nearly collapsed. So big, no one dared to buy it, so Yun cut it up and dried it out and the entire village feasted for a week. Or: When Sok Chetra was young, the fish in the lake were so plentiful they jumped into her boat. Or, even just: Ly Yoeu used to be able to support his family from fishing alone.

The new stories are like this one, shouted from the water by a passing fisherman: “I’m concerned that if there are no fish, I will not eat.”

For half of the year, Tonle Sap Lake is an elongated figure eight in the heart of Cambodia. At the peak of the six-month dry season, the lake covers about a thousand square miles, its edges demarcated by forests, grasslands, paddy fields, and red roads. During the wet season, roughly May to November, all of that disappears: Viewed from a satellite, the lake’s prodigious floodplains, which can cover 6,000 square miles, make it look as though half the country has vanished below the sea.

The lake operates on a flood-pulse system, like a beating heart, emptied and filled through the arterial Tonle Sap River, a major tributary of the Mekong. During the dry season, the eponymous river is pushed toward the Mekong; come rainy season, when monsoons swell the Mekong, the Tonle Sap reverses course entirely, the only river in the world to do so seasonally. Water rushes toward the lake, spilling into the plains, forests, and paddy fields surrounding it.

With the water comes the fish — billions of them, representing more than 100 species, which migrate from higher reaches of the Mekong down through the Tonle Sap river and into the lake. Across the globe, only a handful of countries — all many times the size of Cambodia — boast larger inland fisheries. None rely on their lakes to the extent that Cambodia does. The fish, some 500,000 tons of which are caught each year, feed the nation, providing the main source of protein for as much as 80 percent of the population, and they feed Cambodia’s neighbors, who import thousands of tons each year as part of a $2 billion industry.

For as long as there has been documentation of Cambodia, the lake's abundance has been noted. In the early 1300s, a Chinese emissary named Zhou Daguan marveled at what he termed the Freshwater Sea. “There are very many fish whose names I don’t know, all of them coming from the Freshwater Sea ... there are giant soft-shell turtles and alligators as big as large pillars ... there are crocodiles as big as boats.... They get clams, mud clams and pond snails just by scooping them out of the Freshwater Sea,” he wrote in A Record of Cambodia: The Land and Its People. A half-millennium later, in 1872, French explorer Louis de Carné remarked upon the “astonishing harvest of the waters.” As recently as a decade or two ago, fishers recount, stocks were so plentiful they could dip a bowl in the water and come up with enough food for dinner.

Those days appear to be gone for good. A trifecta of economic development, illegal fishing, and climate change is changing the ecology of the lake, permanently weakening the pulse system and wiping out fish stocks. Last year, the Global Nature Fund deemed Tonle Sap to be the “most threatened” lake in the world. All along the Mekong, Chinese-funded hydropower dams are ballooning as the rapid economic growth of the region runs headlong into an electricity shortfall. On the lake, corruption has seen large trawlers continue to ply protected areas, while individual fishermen increasingly take up their own small-scale illegal fishing. A changing climate, meanwhile, has led to devastating droughts in recent years. Few on the lake have much hope for the future generations. “Our children’s grandchildren may not see the fish,” Hon Bunly, a 55-year-old living along the lake, told us.

In May of last year, when the rains had yet to come and a yearlong drought that began in mid-2015 was at its peak, two photographers, a translator, and I spent about a week circumnavigating the lake. We started near the northern tip, in Siem Reap province, home of Angkor Wat, before heading down to Battambang, Pursat, and Kampong Chhnang provinces, a trip of about 300 miles. Everywhere we went, we asked people what type of fish they don’t see anymore: They don’t see kanchos and they don’t see kompleang. There’s no kanchan chras and there’s no pkar ampil. People told us they were still catching fish, but they were smaller, and fewer in number and fishers had scant faith they would be there in the future.

On a searing-hot afternoon, we visited Kampong Khleang village, located about an hour’s drive outside Siem Reap city. For half the year, water drowns the village, rising up to 20 feet. All along the roads, houses are perched on dizzyingly high stilts. In the vast spaces underneath the homes — where residents store nets, traps, motorbikes, and livestock during the dry season — we chatted with people about the effects of the drought as they repaired shrimp traps or lounged in hammocks.

Chum Kear, a 61-year-old fisherman and his wife, Kay Oeun, invited us into their home. Outside, far underfoot, children ran shrieking through the hard dirt street. During the wet season, the lake swells so much that it can lap at the door; in particularly rainy years, rooms have flooded. The couple shares the house with the youngest of their 10 children and a few of their 18 grandchildren. “A long time ago, it was so good," Kear said of the fish harvest. "Now it’s so bad. The big problem is there are no more fish any more. This year, I can’t make money at all and owe money to the bank."

Unable to catch enough fish, or afford the vegetables, meat, and staples sold by vendors paddling small wooden boats, Kear and Oeun, along with many of their neighbors, were simply eating less.

Like many of the older generation, the family has lived in the same spot on the lake since the fall of the Khmer Rouge in 1979. In the decades after the brutal regime crumbled and its forced agricultural collectives were disbanded, the population living on the lake rapidly expanded, to more than 1.2 million people today — and more than half of Cambodia’s population live within the floodplains.

But with the pressures mounting, some on the lake felt they had no choice but to leave. After departing the stilted villages in Siem Reap, we moved on to Pursat, where we hired a boat to to take us to some of those floating villages. The pilot, Seng Sokum, pointed out empty homes as we floated by. “In each village, families have some members somewhere else," he told us. "Sometimes two or three people.” In the evening, we returned to the spectacle of a massive truck being loaded with the boats and all the worldly belongings of an ethnic Vietnamese family. “In 20 years we’ve never been back [to Vietnam],” the woman told us, in Khmer. “But business is bad here and I can’t make enough to eat.” By last September, hundreds, if not thousands, of families had made the same move.

“Cambodian people depend on fish in Tonle Sap Lake," said Thinny Sothy, the deputy chief of the Fisheries Administration's Siem Reap cantonment. "They eat [141 pounds] of fish a year, including dry fish. Even just in cooking food they use prahok,” a pungent, fermented fish paste that is a local staple. “All the people depend on Tonle Sap Lake. Rural families may raise chickens but they sell the chickens to buy prahok.”

The United Nations Food and Agriculture Organization has estimated that the annual per capita consumption of fish amounts to 140 pounds a year (though others put that figure closer to 86 pounds), compared to an average global consumption at 44 pounds a year. Near the end of the meeting, Sothy told us he suspects the lake cannot continue in its current state. “I’m also concerned about the lake supporting the people,” he said. “Our strategy is to encourage them to do another business while fishing, in order to help families live better.”

Until late 2011, vast portions of Tonle Sap Lake were divided into fishing lots, a practice that dated back to the French colonial era; in its modern iteration, fishermen paid hundreds of thousands of dollars for a two-year license to all the fish within a given plot, which could span over a hundred square miles. The practice was deeply mismanaged and abused, and every so often, Cambodia’s strongman prime minister, Hun Sen, would cancel certain plots, then open them up to the masses as part of a populist campaign. In the lead-up to what would prove a particularly contentious 2013 election, the lots were annulled entirely. Fishermen and researchers alike initially cheered the closure, but the intervening years have been disheartening: Many of the lots were turned into conservation areas, a crucial tool for sustaining fish stocks — but open to the same corruption that routinely damned the prior lot system. Large-scale commercial boats are known to trawl the water deep within the lake. While Lem Sita, a fish buyer in Kampong Luong, a large floating village in Pursat’s Krakor district, said that illegal fishing is occasionally “cracked down” upon by fishery officials in a show of force — particularly this year, in another pre-election bid — the problem is far from addressed in full.

Sita used to own a fishing plot. “It was good, you could get big fish,” she recalled on a hot, quiet morning. “A few years ago Prime Minister Hun Sen opened up the lots for everyone and there was too much fishing. When the government realized the fish were almost finished, they set them up as fisheries again.” In the course of our conversation, only two small boats arrived to sell fish, each barely a pound. In previous years, Sita said, she processed “many tons each day." When we spoke to her in 2016, she estimated that she was buying about 220 pounds a day, and her staff of five had been whittled down to two nephews. “My parents worked as fish sellers, but it’s just me now, I am the last one. My kids don’t want to do it,” she said. “All have their own businesses and I want to close up this business.”

Water and Cambodia are inexorably linked. The vast Angkorian cities utilized highly complex water-management systems made up of canals, reservoirs, and hydraulic engineering. Today, the floodplain system brings in the silt and water to grow millions of tons of rice. The pulse system is so vital that one of the biggest holidays on the Cambodian calendar, Water Festival, is dedicated to it. Each November, millions of Cambodians gather for boat races, concerts, and celebrations to mark the end of rainy season and the reversal of the Tonle Sap.

On the lake and along its tributary rivers, Water Festival also marks the start of fishing season. With winds and rain dying down, and the lake at maximum capacity, the fishing is at its best. Over the next few months, as the lake dips lower and lower, men, women, and children haul in as much as they can — to eat, to pay back last year’s dry season debts, and to purchase the supplies that will take them through the slower months. As it wears on and there are fewer fish to be caught, some people migrate to dry land, where they raise chickens or work as hired farm laborers, among other things. Some stay on the water, catching more seasonally available species like shrimp. Those living near the edge of the lake, in more permanent stilted homes, fish in the waterways leading back toward the lake, and take on seasonal work.

The dry season can become hot, even unbearably so, but it remains part of the normal order. Drought is something different. In 2016, Southeast Asia faced one of the worst droughts in recorded history. Tens of thousands of acres of crops were destroyed, rivers dried up, and health problems flourished. A massive El Niño that started in the middle of 2015, following a smaller 2014 El Niño, stopped the rainy season early and sent temperatures soaring across the region. In Cambodia, fish exports plummeted 21 percent.

One toll of climate change is extreme weather at either end: higher highs, lower lows. In the coming years, it is expected that both droughts and flooding will worsen. The temperature of the Earth in 2016 was higher than had ever been recorded. For the first time ever, forest fires broke out on the Tonle Sap, damaging hundreds of thousands of acres and killing untold numbers of animals. The fish yield was so bad many fishers gave up trying, falling into deeper and deeper debt that they hoped to offset when the rains came.

A year after the drought, which ended in June 2016, the impacts of the extreme weather pattern were still being felt on the lake. One of the unexpected things fishermen had reported was that over the past year, the lake had become windy in a way that no one could recall having seen before. With the forest fires and deforestation decimating the normal buffers, wind whipped past unimpeded, making the fishing difficult in an entirely new way.

In March 2017, we returned to one of the floating villages we had visited a year earlier. Kampong Prak is just one of a string of floating villages in Pursat province’s Krakor district, on the southwestern edge of the lake. The night before we visited, an unseasonable storm lashed across the province. It snapped an anchor rope at the home of 71-year-old Mok Hien, forcing his family to stand in the knee-high water for an hour to hold the floating house steady. “The wind is getting stronger and stronger, and I was afraid the house would collapse,” Hien explained.

On top of climate change, hydropower is exacerbating the troubles facing the Tonle Sap. A string of dams along the main stem and tributaries of the Mekong — some built, some being constructed, and some planned — will lead to plummeting fish stocks, campaigners have long warned. The dams block crucial migration pathways, destroy ecosystems, and lead to siltation upstream and nutrient loss downstream. Decades of advocacy, however, have fallen on deaf ears. Governments along the Mekong insist dams are necessary to supply electricity to growing populations and industries. The costs are steep. One model, carried out by a team from Stanford and Princeton universities and several researchers in Cambodia, predicted a 51 percent decline in fish production in the Lower Mekong Basin should all proposed dams go ahead. At the moment, China has seven dams on the upper Mekong; Laos has three in the works. In total, 11 large main-stem dams are planned in Cambodia, Laos, and Thailand; another 21 are planned in China.

For those living on the lake, such figures translate into stark realities.

“If I were the prime minister, I would not let the dams be built. If there are no dams, the Tonle Sap’s beauty would be the same as it was 20 years ago. We want a new government because the current administration does not care about poor families, only their families. Cambodians should advocate and demand what they want,” An Socheat, a community leader for the Fisheries Action Coalition Team, a group of nongovernmental organizations that have mobilized local residents to advocate for and protect their waterways, told us. Last year, shortly after the drought, Socheat went to Thailand for a workshop on Mekong dams. “I came back to tell the people in the community: Even though we are far from dams, we are affected. Now they understand we also need to support the people who fight against dams.”

Be it from drought, damming, or overfishing, when the catch drops, fishers grow desperate. Many are increasingly resorting to illegal fishing tactics, like using nets with miniscule holes, fishing during the off-season, or fishing inside of conservation areas, all of which imperils spawn and breeding stocks and further exacerbates the problem.

Sok Chetra, 77, and her husband Mok Nhor, 78, have lived in near the protected wetlands of Prek Toal, at the lake’s northern tip, since they were teenagers — first on a floating home, and later on a stretch of land. Here, the waterways cut through verdant patches of ferns and mangroves, and snowy egrets glide low. All along those waterways are hundreds of fish traps — nets spooled around pieces of wood driven into the soft river floor. Many of these are illegal, made with wood cut from the protected area, or with netting whose holes are smaller than the legal limit. “When we install the traps, the fish officials come and move them,” said Nhor. “They say we are illegal,” Chetra added. “But if we cannot do this we will die.”

Across the lake from Siem Reap, in Kampong Chhnang province’s Krakor district, the conservation area is patrolled by a few dozen fishery officials. The fishery officials’ patrol base is a large floating houseboat located about five miles from the shore. Surrounding it are platforms full of confiscated nets, traps, and the odd powerboat.

When we met the district fisheries chief Pen Vuthy on the floating base at the height of the drought in 2016, he told us the amount of illegal fishing had become staggering. "They can’t have enough to support their families. Usually they would get 30 kilos a day, this year they can’t even get five,” he said. “More and more crime is happening. It’s like if there’s a beautiful daughter in your home — the men want to come inside. Outside they can’t fish, so they run the risk by coming in the protected area, even if they face jail.”

I asked him if people plead for leniency given the circumstance. “Some of them beg me to release [their equipment], but I can’t do it. I need to report it to the commune and district chief and I make them sign a paper saying they won’t come back. Mostly they respect it, we educate them and they don’t come back.”

Yem Yun, 43, a fisherman in Prek Toal, spoke openly about the growing pressures on small-scale fishers like himself. The only place to catch big fish, said Yun, is near the conservation area. “Sometimes I put my net in the conservation area, the official takes the net, and I have to pay to get it back,” he said. The fine, a bit less than $4, is a reasonable deterrent, Yun thinks. But the problem is larger than one fisherman. “If it’s really a conservation area, I support it, but I’m just concerned officials are corrupt and allow other fishermen to catch,” he said. “There’s lots of illegal fishing, there’s small nets, there’s Vietnamese trawlers.”

Back in Kampong Khleang, one year after we first arrived, we met 57-year-old Vien Ny, who had lived within a few miles of the village his entire life. “When I was young the water was fresh, blue color,” he told us, gesturing toward a muddy inlet coated with trash. This year was an improvement on last, but not by much. In fact, the fish stocks accessible from this area have dropped so much that nearly everyone in this village catches a type of small, cheap, freshwater shrimp now instead. Heaped beneath each home are hundreds of shrimp traps, simple wire-and-net affairs to be strung out en masse during the rainy season. In the dry season, Ny and most of his neighbors take on ad hoc jobs, the odd bit of construction or carrying loads from the port.

Dressed in a fatigue cap, a relic from his former life as a soldier, Ny dragged on a cigarette as a he spoke to us about the changes. All around him, his children and grandchildren ran in loops — climbing on and off his motorbike, clambering under his legs. We asked if he’d like them to follow in his footsteps. “I can’t predict their future but I think I want them to find other jobs,” he said. Catching fish, he explained, was simply the work done by someone with no farmland, no education, and no other option. “When we don’t have any job, what else can we do? This is why we are fishermen. If I had knowledge like you do I would do a different job.”

This story was written as part of Uncovering Security , a media skills development program run by the Thomson Reuters Foundation, Stanley Foundation , and Gerda Henkel Stiftung.

Abby Seiff is an award-winning freelance journalist with a decade of experience reporting in Asia.

Nicolas Axelrod is a filmmaker and multimedia storyteller. Born in Australia, currently based in Bangkok, his work takes him around Asia and across continents, with a focus on climate change and development.

Translation and additional reporting by Chhorn Chansy and Seng Sophea

Fact checked by Pearly Huang

Copy edited by Rachel P. Kreiter