Photos: Fighting sea lamprey in Lake Superior

Environment

1 United States Fish and Wildlife Service biology technician Tom Davies displays the power of the lamprey's suction Thursday morning along the Brule River in northern Wisconsin. 
2 Lamprey use their many teeth to latch onto the side of lake trout and suck their body fluids until the trout die. It's estimated that each lamprey kill between 10 and 40 pounds of lake trout during their lifespan, which is estimated at 18 months. 
3 Great Lakes Indian Fish and Wildlife Commission section leader Bill Mattes, right, retrieves a net containing one lamprey from GLIFWC fisheries aide Acorn Armagost (not pictured) while Tom Davies, left, with the United States Fish and Wildlife Service looks on Thursday, May 24, 2012, near the Brule River in northern Wisconsin. 
4 Great Lakes Indian Fish and Wildlife Commission fisheries aide Acorn Armagost uses a net to search the bottom of a containment area for lamprey Thursday, May 24, 2012, along the Brule River in northern Wisconsin. A step system is used to catch the lamprey. A dam along the Brule River is in place that is too high for fish and lamprey to pass. On the side of the river is a step system, which can be surpassed by trout and other fish, but at one portion of the system, the steps are too high for the lamprey to jump and they end up swimming into a containment area that they cannot escape. 
5 Lamprey are caught and thrown into coolers for later examination Thursday, May 24, 2012, near the Brule River in northern Wisconsin. 
6 A step system along the Brule River in northern Wisconsin is used to spare fish, but catch lamprey. 
7 A faint sign of a lamprey wound is visible on the side of this Siscowet Lake Trout captured Tuesday , May 22, 2012, on Lake Superior north of Duluth, Minn. 
8 From nets dropped in 150 feet of water, this lake trout made it's way to the surface into the hands of Minnesota Department of Natural Resources fisheries biologist Corey Goldsworthy (not pictured) to be examined for signs of lamprey wounds Tuesday, May 22, 2012, on Lake Superior north of Duluth, Minn. 
9 The Minnesota Department of Natural Resources completed their May survey of lake trout Tuesday, May 22, 2012, on Lake Superior north of Duluth, Minn. The lake trout caught in nets were being examined for signs of lamprey wounds. 
10 Minnesota Department of Natural Resources fisheries biologist Corey Goldsworthy, right, reacts quickly to catch a lake trout that was becoming untangled from its net Tuesday, May 22, 2012, on Lake Superior north of Duluth, Minn. With the help of intern Ryan Bart, Goldsworthy was hauling in nets dropped into Lake Superior to catch lake trout as part of their May survey of the fish to look for signs of lamprey wounds. 
11 Not all the fish caught in nets are lake trout. Here, intern Ryan Bart, left, and Minnesota Department of Natural Resources fisheries biologist Corey Goldsworthy, work to extract two smelt that were caught in nets they dropped into Lake Superior to catch lake trout as part of their May survey of the fish to look for signs of lamprey wounds Tuesday morning on Lake Superior north of Duluth, Minn. 
12 Minnesota Department of Natural Resources fisheries biologist Corey Goldsworthy, left, and intern Ryan Bart retrieve a buoy that was in Lake Superior to mark the location of nets dropped to catch lake trout as part of their May survey of the fish to look for signs of lamprey wounds Tuesday, May 22, 2012, on Lake Superior north of Duluth, Minn.