In order for natural resource managers to conserve or restore native imperiled species, they need to clearly understand the status of current populations, including patterns or trajectories in those populations. The GLSC tracks the recovery of the native, and culturally-significant, lake trout following basin-wide restoration efforts underway since the 1960s. Scientists also study the interaction of two native top predators, lake trout and burbot, as natural lake trout reproduction increases. Other GLSC research focuses on describing the degree to which a native prey fish, cisco, has recovered in Lake Superior following a population collapse in the late-twentieth century. This information is critical for the long-term health of the ecosystem.