The Mekong is home to over 1, 200 different species of fish, more than any other river save the Amazon and the Congo.

ECONOMIST: The Mekong river

Organizations that endorse removing the four lower Snake River dams to save salmon say the resolution is unfair.

CNN: Snake River dam resolution called unfair

Often they follow a tragedy, such as when Sunnis risked their lives diving into the Tigris to save hundreds of Shia pilgrims who fell into the river after the collapse of a bridge in 2005.

ECONOMIST: The euphoria of a footballing victory faded fast

He dove into the river to save a passenger.

FORBES: Small Business Owners Should Be Obama's Lenny Skutnik