.dropcap { color: #838078; float: left; font-size: 82px; line-height: 60px; padding: 5px 8px 0 0; } James Marlowe zips along the glassy lake surface of the water in his aluminum fishing boat, and the town of Łutsël K’é quickly falls from sight. We stay close to the shoreline, avoiding hidden reefs, and steer straight for his net. It’s closing in on midnight, but Great Slave Lake—the deepest lake in North America and the 10th largest in the world—is flashing with fish and the tree-covered hills are aglow in the setting summer sun. Marlowe cuts the motor and begins hauling in the 150-foot net hand-over-hand. Splop! The first fish lands in a large plastic bin. Splop! Splop! Marlowe moves along the net, plucking whitefish from its mesh. With some effort, he untangles a 30-pound trout and heaves the rare find into the bin. “Oh, there are still more fish! It’s not going to stop, man,” he says with a laugh. Since he was a teen, Marlowe has hunted...