Michael Hadley | Division of Wildlife Resources Wayne Gustaveson, a Utah Division of Wildlife Resources fish biologist, displays a largemouth bass he caught at Lake Powell. Since 2012, the lake’s striped bass have been under a consumption advisory due to the presence of mercury found in fish south of Dangling Rope Marina. A new study by the U.S. Geological Survey has found the highest concentrations of the toxic metal are in the side canyons feeding into reservoir.