This gallery is part of a special National Geographic News series on global water issues.
Hard-hit by a months-long drought, a waterway within the Amazon Basin trickles to a halt in Manaus, Brazil (see map), on November 19.
The Negro River, a major tributary of the Amazon River, dropped to a depth of about 46 feet (14 meters)—the lowest point since record-keeping began in 1902.
(Related: "Amazon Losing 'Flying Rivers,' Ability to Curb Warming.")
About 60,000 people in the Amazon have gone hungry as falling river levels paralyzed transport and fishing. Millions of dead fish have also contaminated rivers, leading to a shortage of clean drinking water, the Reuters news agency reported. (How much do you know about drinking water? Test your knowledge with a quiz.)
Caused by El Niño—a cyclical warming of tropical waters in the central and eastern Pacific Ocean—such a severe drought usually occurs once in a century. But the 2010 disaster comes just five years after the latest Amazon "megadrought," according to Reuters.
The drought also fits within predictions of climatic extremes this century due to global warming, Reuters reported. (Explore an interactive map of global warming's effects.)
PHOTOS: "Alarming" Amazon Drought—River Hits New Low
A megadrought has gripped the Amazon, drying up rivers and cutting off thousands of forest communities dependent on boat traffic for survival.