In southwest Bangladesh, fishermen get help from unusual partners: river otters. For generations, fishermen have trained river otters to catch fish. But the rare tradition is fading away as rivers change and become more polluted, leaving fewer fish to catch. On a long wooden boat, river otters squeal and squirm inside a large bamboo box. On this sunny autumn day in Narail District, fishermen guide the boat along the green waters of the Chitra River. When they open the box, six brown otters scramble out and dive into the river. They gleefully glide alongside the boat propelled by fishermen with long oars.