Ho San stands next to the wooden boat he calls home and pointed to the exposed river bank surrounding Chroy Changvar, the riparian peninsula where the Mekong and Tonle Sap rivers converge in Phnom Penh.
"You can see from the mud where the water normally reaches," the Cambodian fisherman tells dpa. "We've never seen it this low. When the water is like this, we go hungry."
The 4,350km Mekong River, which flows through China, Myanmar, Thailand, Laos, Cambodia and Vietnam, and supports the livelihoods of an estimated 60 million people, is in crisis.
A punishing drought felt along much of the river has extended into a second year, resulting in record low water levels.
Influenced by the El Nino weather system, rainfall levels in the Lower Mekong Basin have fallen sharply. From January to July, it received 397mm of cumulative rainfall – 36% less than 2019,62% less than 2018.
That is some 45% less rain than average recorded for the period between 2008 and 2017.
At the same time, experts say upstream hydropower dams in China are also harming the river's ecology, including the monsoon flood pulse, which is vital for fisheries and agriculture in the region.
Furthermore, sand dredging is damaging riverbanks and severely disrupting sediment flows.
The World Wildlife Fund's Marc Goichot, a freshwater systems expert, says the accumulative effects were irrevocably changing the Mekong.
"Once you reach a threshold, it's too late to get it back," Goichot says. "The river will re-adapt, but it will be a different river, and the entire relationship to the river will have to be reinvented and that could have huge costs for the most vulnerable."
One bellwether of the river's perilous state is the Tonle Sap. Dubbed the Mekong's main "fish factory," Cambodia's inland lake is the most productive in the region.
During the wet season, the lake is normally engorged as the Tonle Sap river, due to the power of the monsoon rain-swollen Mekong, reverses course and floods the lake basin, surrounding plains and forests.
However, due to the Mekong's weak flow, this year's reversal – as well as last year's – did not begin until early August, months later than normal. Its water levels are now some of the lowest on record, according to the Mekong River Commission (MRC).
Those who depend on the rising waters are struggling. Salas Vel, an elder in the Chroy Changvar fishing community, says catches had declined by more than half. The future held little hope, he says.
"Normally the water spills over into the lakes and ponds so the fish can breed, but now that can't happen, and fish raised only in the river will not be good enough," Vel says.
Fishermen with enough money bought tuk tuks while others found work in construction. Those without capital "have to endure," he says.
Low water levels are compounded by the economic fallout from the pandemic.
Villagers like Kheng Kimna, who runs a homestay in Kampong Phluk outside Siem Reap, rely on tourists coming to see the flooded forests surrounding the community.
"The lake now is very shallow. We have to use smaller boats in certain areas," says Kimna, who's been without a booking since early this year.
She would usually host between four and 15 customers. "Now I have no one."
The MRC in August recommended downstream countries ask China to release more water from its dam storage.
Beijing faces scrutiny since a report concluded that its dams had held back "more water than ever" in 2019, despite above-average rainfall.
US diplomats in the region seized on the issue, making the Mekong another front in the rivalry between Washington and China, which points to its own study that claims its dams had helped alleviate drought conditions downstream.
Chinese premier Li Keqiang in August pledged to share more water management data with downstream states.
In a briefing paper, regional analyst Carl Thayer says China's track record suggested it would unlikely provide full transparency, especially if "the data reveals that downstream states are disadvantaged."
Stimson Center Southeast Asia analyst Courtney Weatherby says dam management in China prioritised power generation and flood prevention, which "made sense" in a Chinese context of avoiding damaging floods but ignored the bigger picture.
The benefits of the annual flood pulse to agriculture, fisheries and downstream ecosystems like the Tonle Sap in Cambodia and the Mekong Delta in Vietnam were "magnitudes higher" than the damages, she says.
"If we see significant changes to the flood pulse and rains due to climate change that are exacerbated by upstream infrastructure, that's a concern for rice production, that's a concern for livelihoods," she says.
WWF's Goichot says there are solutions, but they require action from governments and intergovernmental organisations.
"We are in a very deep crisis and it is now, not next year, that we need to act and get the plan right." – dpa