Great Lakes Fish Tag and Recovery Lab
Coded Wire Tagging Completed for 2016
BY KEVIN PANKOW, GREEN BAY FWCO
The Great Lakes Fish Tag and Recovery Lab, headquartered at the Green Bay Fish and Wildlife Conservation Office (FWCO), has concluded tagging 93 lots of the 2016 year class of lake trout. The team tagged 4,916,035 lake trout with a coded wire tag (CWT) and adipose fin clip (AD) at three US Fish and Wildlife Service (FWS) Region 3 National Fish Hatcheries (NFH), one USFWS Region 5 NFH and one Michigan Department of Natural Resources State Fish Hatchery (SFH) between July 13 and September 27. The lake trout tagged at Marquette, Pendills Creek, Jordan River and Iron River hatcheries are destined for stocking into lakes Michigan and Huron; the lake trout tagged at Allegheny hatchery are stocked into lakes Erie and Ontario.
To accomplish this task, the lab operated three mobile tagging trailers that automatically injects a CWT and removes the adipose fin of hatchery reared fish with little human handling. The CWT is a 1.1-mm long piece of stainless steel wire etched with a six-digit code that is unique to a group of fish, referring to its year class, strain, stocking location and hatchery origin.
The information gained from CWT returns provides the Service and its partners the ability to evaluate the restoration program from lake trout in lakes Michigan and Huron. Information gained from the recapture of these fish in future years in assessment and sport fisheries include: estimates of natural reproduction, growth rates, evaluate post-release survival of various strains and year classes, movement of lake trout within and among the lakes, assess the contributions of the hatchery-reared and wild fish to regional fisheries, and to evaluate the performance of rearing and stocking practices. A mission of the Service is restoration of native species to the Great Lakes, specifically the lake trout. By tagging and recovery of lake trout through assessment surveys and sport catches, fishery managers are provided a tool to monitor the success of rehabilitation of lake trout in lakes Michigan and Huron.
Since the program’s inception in 2010, over 39 million lake trout stocked into the Great Lakes have been ADCWT by the Lab. In addition, 23 million Chinook salmon, Atlantic salmon, brook trout and brown trout have been coded-wire tagged and/or adipose fin clipped. The program is currently funded by the Great Lakes Restoration Initiative.