Controlling an Invasive Predator

Controlling an Invasive Predator. Trail Creek Sea Lamprey Barrier and Fishway. , The U.S. Fish and Wildlife Service and Great Lakes Fishery Commission work in partnership with the Indiana Department of Natural Resources to control sea lampreys in the Great Lakes. Tributaries harboring larval sea lampreys are periodically treated with lampricides to eliminate or reduce the populations of larvae before recruitment to the lake as parasitic adults. However, alternative controls such as barriers and trapping are also used to prevent access to spawning grounds or to remove sea lamprey adults prior to spawning., Trail Creek is one of several locations in the Great Lakes where a fixed low-head barrier has been constructed to prevent sea lampreys from migrating upstream to spawning grounds. The barrier seen here is a multi-purpose structure that facilitates sea lamprey trapping and fish passage., [Captions:] , What's so bad about sea lampreys? , - Sea lampreys are parasites; they feed on the blood of other fish species in the Great Lakes. , - Sea lampreys are native to the Atlantic Ocean, but are able to live in both fresh and salt water. , - One sea lamprey can kill up to 40 pounds of fish during its parasitic phase, which lasts 12 to 20 months. , - Sea lampreys are a major threat to the Great lakes fishery if left uncontrolled., Sea Lamprey Wound , Sea lampreys are so destructive that under some conditions, only one of seven fish attacked by a sea lamprey will survive. Sea lampreys prey on all species of large Great Lakes fish such as lake trout, salmon, rainbow trout (steelhead), whitefish, chubs, burbot, walleye, catfish, and even sturgeon., Trapping , Sea lamprey traps are operated at various locations throughout the Great Lakes, often in association with barriers. Traps are designed to capture lampreys as they travel upstream to spawn. Sea lampreys caught in the traps are used for research., Fish Passage , Low-head barriers allow jumping species to migrate upstream; other desired species can be passed upstream through a trap and transfer operation., Sport Fishing , Overall, the sea lamprey control program has been tremendously successful. Ongoing control efforts have resulted in a 90% reduction of sea lamprey populations in most areas, creating a healthy environment for fish survival and spawning. Continued cooperation and support will allow the program to keep sea lamprey populations at levels that lessen the impact to our fishery.