If their food supply hits a low cycle, lake trout simply throttle down their metabolism and stop growing as they wait out the lean years. Were a trout to let its guard down in this fashion in the ocean, a bigger fish likely would swallow it whole. But adult lake trout in the Great Lakes food web only had to worry mostly about eating, not being eaten. This ability to pace its growth with available food sources made it the perfect fish to regulate—or, more accurately, harvest—the slow flow of energy through the Great Lakes that starts 93 million miles away.
