How the waters off Catalina became a DDT dumping ground

Not far from Santa Catalina Island, in an ocean shared by divers and fishermen, kelp forests and whales, David Valentine decoded unusual signals underwater that gave him chills.

The UC Santa Barbara scientist was supposed to be studying methane seeps that day, but with a deep-sea robot on loan and a few hours to spare, now was the chance to confirm an environmental abuse that others in the past could not. He was chasing a hunch, and sure enough, initial sonar scans pinged back a pattern of dots that popped up on the map like a trail of breadcrumbs.