Endangered pink river dolphins face a rising mercury threat in the Amazon

PUERTO NARINO, Colombia — A flash of pink breaks the muddy surface of the Amazon River as scientists and veterinarians, waist-deep in the warm current, patiently work a mesh net around a pod of river dolphins.

PUERTO NARINO, Colombia — A flash of pink breaks the muddy surface of the Amazon River as scientists and veterinarians, waist-deep in the warm current, patiently work a mesh net around a pod of river dolphins. They draw it tighter with each pass, and a spray of silver fish glistens under the harsh sun as they leap to escape the net.

When the team hauls a dolphin into a boat, it thrashes as water streams from its pink-speckled sides and the crew quickly ferries it to the sandy riverbank where adrenaline-charged researchers lift it onto a mat. They have 15 minutes — the limit for how long a dolphin can safely be out of the water — to complete their work.

Fernando Trujillo, a marine biologist leading the effort, kneels beside the animal’s head, shielding its eye with a small cloth so it can’t see what’s happening. He rests his hand gently on the animal and speaks in low tones.

“They’ve never felt the palm of a hand. We try to calm them,” said Trujillo, sporting a pink dolphin bandana. “Taking a dolphin out of the water, it’s a kind of abduction.”

One person counts the dolphin’s breaths. Another wets its skin with a sponge while the others conduct multiple medical tests that will help show how much mercury is coursing through the Amazon’s most graceful predators.