MPR News / Lamprey on the lam… for now

Earlier this month, I found myself on the shore of the Brule River in northern Wisconsin with a lamprey attached to my arm. If you don’t know what a lamprey is, you’ll see below and you might turn away. These creatures leave a lot to be desired in the looks department, but hey, apparently they’re tasty enough to make a pie out of them for the Queen of England. I digress.

Lamprey have been devastating to the Great Lakes ecosystem having nearly wiped out the trout populations in all the Great Lakes except Lake Superior. The sheer size of Superior and the fact that it was the last lake to be invaded by the boneless fish gave officials time to react. Today, about 90% of lamprey are killed before they can do any harm to Lake Superior trout. Despite this, the remaining 10% take as many trout as do commercial fisherman. Yep, they are that devastating.

The story for Minnesota Public Radio examined the success story surrounding lamprey control on Lake Superior.  It’s worth a read or better yet, listen to reporter Dan Kraker tell the story about the disgustingly fabulous boneless fish.

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.

Minnesota Department of Natural Resources fisheries biologist Corey Goldsworthy (left) and intern Ryan Bart (right) haul in line from nets that were 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.

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 morning on Lake Superior north of Duluth, Minn. With the help of intern Ryan Bart (left), 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.

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 morning on Lake Superior north of Duluth, Minn.

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 (right) 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.

Minnesota Department of Natural Resources fisheries biologist Corey Goldsworthy untangles a lake trout from nets that were 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. This trout showed no signs of lamprey wounds.

The Minnesota Department of Natural Resources completed their May survey of lake trout Tuesday morning on Lake Superior north of Duluth, Minn. The lake trout caught in nets were being examined for signs of lamprey wounds.

A faint sign of a lamprey wound is visible on the side of this Siscowet Lake Trout captured Tuesday morning on Lake Superior north of Duluth, Minn.

Minnesota Department of Natural Resources fisheries biologist Corey Goldsworthy (left) and intern Ryan Bart (right) 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 morning on Lake Superior north of Duluth, Minn.

A step system along the Brule River in northern Wisconsin is used to spare fish, but catch lamprey.

Lamprey are caught and thrown into coolers for later examination Thursday morning near the Brule River in northern Wisconsin.

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 with the United States Fish and Wildlife Service (left) looks on Thursday morning near the Brule River in northern Wisconsin.

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 morning 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.

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.