Tagging fish is a common fisheries management technique. Every lake sturgeon handled by U.S. Fish and Wildlife Service biologists gets a Passive Integrated Transponder (PIT) tag. The tag has a unique 15-digit code to identify that fish. The tag is a half inch long, and enclosed in glass.
The tag is only useful when tagged fish are re-caught in the future. The data yielded will show how far fish move, how much they grow, and give some idea of how long they live. The tags may even show how attached an individual fish is to particular habitats, like spawning sites, over time. When enough fish are tagged, biologists can accurately estimate population size.
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| Joshua Schloesser with the Ashland Fish and Wildlife Conservation Office carefully injects a lake sturgeon with a PIT tag, just under its skin. This fish was caught in near Ontonagon, Michigan. USFWS photo |
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| Smaller than a dime is tall, PIT tags are of great value to fish biologists. USFWS photo |
According to fish biologist Joshua Schloesser at the Ashland Fish and Wildlife Conservation Office in Wisconsin, PIT tags work well for lake sturgeon in the Great Lakes because the fish can live over 100 years and have the ability to move long distances. The Wisconsin DNR recently recaptured a lake sturgeon in Chequamegon Bay, Wisconsin, that was originally PIT-tagged near L'Anse, Michigan.
Lake sturgeon are in fact very mobile.
Lake sturgeon are in fact very mobile.
