Small fingerlings roiled the water in the translucent plastic tubs placed before ready volunteers in the Red Cliff tribal fish hatchery at Wisconsin’s northern edge. The agitated three- to six-inch coaster brook trout–known as fry–made the water appear to be boiling. A mild anesthetic was added and soon the young trout were calmed and primed to undergo the fish version of cattle branding–a clipping of their fins that will identify them as the Class of 2012. In mid-May, some 24,000 of these trout graduated from hatchery rearing tanks and were released into the vast Lake Superior as part of a years-long effort by the Red Cliff Band of Lake Superior Chippewa to reinstate a once-significant strand in the Great Lake’s food web. The band’s hatchery is one of only two that are regionally rearing coaster brook trout; it is the only one using brood fish native to the watershed...