The Mekong River, a powerful 4,350-long river that runs from southern China to southern Vietnam, is one of the most biodiverse places on Earth—second only to the Amazon River. The Mekong is home to a species of critically endangered freshwater dolphin, a giant catfish, and way too many fish, mammals, and crocodiles to list. It's also the engine behind Vietnam's rice industry—the second-biggest in the region. It's basically feeding hundreds of millions of people every single day, making it one of the most-important rivers in the world.  But it's also facing an uncertain future thanks to another, incredibly popular commodity—sand. For decades, sand miners have dredged the river and dug up its banks along stretches from Myanmar to Vietnam to feed an unsuitable regional demand for tiny grains of sand—a key component in concrete and asphalt. The banks of the Mekong are basically the building blocks for the world's cities and roads—and the people of Southeast Asia are paying the price.

In 2016, I decided to set out and travel down the Mekong River to see the effects of sand mining first-hand. I packed 200 rolls of Kodak Porta 160, a Hasselblad panoramic camera, and a rough plan to start in Laos and make my way down-river to southern Vietnam.  Urbanization wouldn't happen without sand. Take Singapore as an example. The wealthy city-state has increased its land mass by some 22 percent since the 1960s by reclaiming land from the sea and making new roads, office towers, and HBD apartment blocks. That makes Singapore, a tiny country that's smaller than my old hometown of New York, one of the biggest sand importers in the world. And a lot of sand comes from the banks of the Mekong.

The constant erosion of the river's banks makes the river itself more shallow (lower riverbanks mean wider, and therefore more shallow, rivers) and that equals fewer fish to sustain local fishing industries and feed the people who live nearby. The ironic part of the problem is that these sand minders live alongside the river too. They are basically working every day to dismantle their own environment and make their own future's more precarious. But no one has time to think about stuff like that when you're trying to feed a family.

Sand mining is an economic necessity for many of the poorer people living along the banks of the Mekong. But the activity is driven by a demand beyond most people's grasp. It was as if they were all floating on the tides of a global industry they had no real control over.  When the currents got too rough it was easy to fall off. And sadly, the only way to hold on was to damage your own environment to such a degree that life is only guaranteed to get even more turbulent in the near future. The waters were gentle on the day I arrived at Lake Jiulong. But, if things continue like they are, the waters won't be for much longer.