STORY: The remains of rare baby river dolphins have been washing up on the shores of Brazil's Lake Tefe in recent weeks.The Amazon rainforest is experiencing its worst drought on record and seeing lower water levels and higher temperatures.

Brazil is enduring its worst drought since nationwide measurements began over seven decades ago, with 59% of the country under stress — an area roughly half the size of the U.S.

Brazilian scientists worry that a few straight days of intense sun could be all it takes to trigger the next die-off of the endangered dolphins.

The carcass of a baby dolphin lay on the sand bank left exposed by the receding waters in an Amazon lake that has been drying up in the worst drought on record. Researchers recovered the dead animal on Wednesday and measured water temperatures that have been rising as the lake's level drops.

The drought's impact extends beyond wildlife. Riverine communities across the Amazon are facing unprecedented challenges.