Great Lakes Fish Tag and Recovery Lab Completes
2013 Chinook Salmon Tagging Season
By James Webster
Green Bay FWCO
The Automated Fish Tagging Trailer set up for coded wire tagging and adipose fin clipping of Chinook salmon at the Illinois Department of Natural Resources Jake Wolf Memorial Hatchery. (U.S. Fish and Wildlife Service photo)
On May 13, the Great Lakes Fish Tag and Recovery Lab concluded the third successful season of their 5-year Chinook salmon mass marking project.
Between March 12 and May 13, lab staff traveled to seven state-operated hatcheries in Michigan, Wisconsin, Illinois and Indiana to coded wire tag and adipose fin clip 2.5 million Chinook salmon destined to be stocked into Lakes Michigan and Huron. An additional 360,000 Chinook salmon were marked, with the adipose fin clip only, and then stocked into Lake Superior.
The Chinook salmon mass marking project is a cooperative effort involving Michigan, Wisconsin, Illinois and Indiana Departments of Natural Resources and the U.S. Fish and Wildlife Service. Each year, biologists from the lab use automated equipment to implant a coded wire tag in the snouts of all hatchery-reared Chinook salmon and simultaneously clip the adipose fin.
The tiny coded wire tag is etched with a unique code that provides identification of the discrete hatchery group, and the adipose fin clip positively indicates that the fish has been tagged and is of hatchery origin. When an adipose fin clipped fish is recovered during agency assessment surveys or from angler interactions, the snout is collected and sent to the lab in Green Bay for tag extraction and reading.
Since 2010, more than 12.9 million Chinook salmon have been tagged and released in Lakes Huron and Michigan. In addition, during the same period more than 15,000 tags have been recovered, extracted and read at the lab.
The information recovered from coded wire tag returns will provide fisheries managers with the ability to accurately estimate levels of natural reproduction, and to identify fish movement within and among the lakes, as well as the resultant contributions to regional fisheries.
In addition, the tag recoveries allow biologists to evaluate the health of the fishery by providing data on growth rates, age of the fish at the time of capture, and the evaluation of hatchery rearing and stocking practices.
The information provided by this project will allow Great Lakes fishery managers to continue making informed management decisions on stocking levels to insure the constant viability of the multi-billion dollar sport fishery.