KOH KONG, Cambodia (AP) — Round a bend in Cambodia’s Tatai River and the virtual silence of a tropical idyll turns suddenly into an industrial nightmare. Lush jungle hills give way to a flotilla of dredgers operating 24 hours a day, scooping up sand and piling it onto ocean-bound barges. The churned-up waters and fuel discharges, villagers say, have decimated the fish so vital to their livelihoods. Riverbanks are beginning to collapse, and the din and pollution are killing a promising ecotourism industry. What is bad news for the poor, remote Tatai community is great tidings for Singapore, the wealthy city-state that is expanding its territory by reclaiming land from the sea. Sand from nearby countries is the prime landfill and also essential building material for Singapore’s spectacular skyline. As more countries ban its export to curb environmental damage – entire Indonesian islands have been all but wiped off the map – suppliers to Singapore scour the region for what still can be obtained, legally or not. Cambodia, a poor country where corruption is rife and laws are often flouted, is now the No. 1 source. Singapore is by no means the only nation taking part in what is a global harvest of sand from beaches, rivers and seabeds. Officials and environmentalists from China to Morocco have voiced concern and urged curbs. As construction booms in emerging economies and more sources dry up, however, exploitation of the remaining ones is likely to intensify. Sand mining began anew in May on southwestern Tatai River, which empties into the ocean almost directly north of Singapore, across 1,300 kilometers (800 miles) of open water. Despite denials by the main owner of sand mining rights in Koh Kong province, two Cambodian officials told The Associated Press that the sand is destined for the island nation.