Tonle Sap crisis develop as Climate Change persists.

"A trifecta of climate change, hydropower dams and illegal fishing are threatening the Tonle Sap, and the people who rely on its fish.

When I first met Ly Heng in May 2016, the forest behind his house was still smoldering — the remnants of the worst drought to hit Southeast Asia in decades. Heng lived along a small river at the top of Cambodia’s Tonle Sap Lake, in a protected area known for its rich biodiversity. At 45, he had never seen wildfires, and never seen the water level of the lake dip so low. Charred sticks and leaves crunched underfoot while Heng led me through the woodland, recounting his neighbors’ efforts to keep the fire from incinerating their houses.

“This is the first time it’s this dry, and the first time the forest burned up,” he said.

Tonle Sap Lake is the largest body of freshwater in Southeast Asia. Its wetlands support critically endangered species like the Bengal florican; its sediment provides nutrients for croplands; its fisheries are among the largest and most biodiverse in the world.

And it has reached a tipping point. Just three years after the 2016 drought, another hit the region earlier this year. Local and global leaders should agree to stem the mushrooming of environmentally destructive hydropower dams, combat illegal fishing and mitigate the impacts of global warming. If such action is not taken soon, the Tonle Sap’s days are numbered. With it will vanish an ecosystem that has supported millions of Cambodians and their neighbors for centuries.

Like the Mekong River as a whole, Tonle Sap Lake is beset by problems both local and global. In recent years, a trifecta of climate change, overfishing and the creation of new dams has threatened to unmake the Tonle Sap.

Agree to disagree, or disagree better? We'll help you understand the sharpest arguments on the most pressing issues of the week, from new and familiar voices.

Fishers have begged the Cambodian government to crack down on the large-scale illegal fishing that takes place inside the lake’s protected areas. Environmental campaigners have urged a moratorium on the megadams dotting the Mekong and its tributaries. Researchers have suggested investment in energy alternatives such as floating solar panels. In December, the 2019 United Nations Framework Convention on Climate Change will convene in Santiago, Chile; if the concept of a changing climate remains a theoretical in the minds of some Western leaders, it is very much a lived experience on the Tonle Sap.

The lake is fed by an extraordinary hydrological phenomenon called a monotonal flood-pulsed system. A tributary known as the Tonle Sap River stretches from the Mekong to the Tonle Sap Lake, reversing course twice a year to fill and empty the lake. In the rainy season, water surges up into the lake, which expands as much as six times its dry-season size, covering 6,000 square miles. In the dry season, water flows back out of the lake and into the Mekong.

That beating heart movement allows fish to migrate and spawn, and carries nutrients up and downriver. Some 500,000 tons of fish are caught in the lake each year, making up part of a $2 billion fish industry and providing the primary source of protein for most Cambodians.

This year, the rains didn’t arrive in May, or June, or July. They didn’t come until August, borne on a series of storms so powerful that thousands had to be evacuated. The Mekong River reached a grim milestone: It dipped to its lowest levels since modern recording began.

Each time the Mekong reaches a new low, the pulse that keeps Tonle Sap Lake alive slows. This year, according to officials, the water in the Tonle Sap River reversed course in July — about two months late. (Others believe the reversal came even later.) Soon, the only river in the world to reverse seasonally may not switch direction at all."

Repost from NYTimes written by Abby Seiff (30 Sept. 2019) - At a Cambodian Lake, a crisis unfolds. [online] available from: https://www.nytimes.com/2019/09/30/opinion/tonle-sap-cambodia-climate.html