Field Notes
U.S. Fish & Wildlife Service
Field Notes Entry   
Early Spring Tagging Takes Place
Midwest Region, April 22, 2014
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Lake Sturgeon just before tagging
Lake Sturgeon just before tagging - Photo Credit: USFWS
Tagging crew hard at work
Tagging crew hard at work - Photo Credit: USFWS

The time to shine has come for the last remaining lot of lake sturgeon at the Genoa National Fish Hatchery. It has been almost a year since this lot of Wolf River strain lake sturgeon arrived at Genoam, and these fish were being held for a very special purpose. Their larger size made this lot ideal to study tag retention of differing fishery tags.

Many partners combined forces including Ashland Fish and Wildlife Conservation Office , Gren Bay FWCO, La Crosse FWCO, and staff from the hatchery to get the fish tagged with PIT tags and Coded Wire tags. The objective of this study was to tag all the lake sturgeon with passive integrated transponder (PIT) tags and coded wire tags (CWT) for tag retention evaluation. Biological and tagging specific data for each fish was entered in a data file so that later tag retention data can be associated with tag type, initial fish size, and tagging procedure/crew.

PIT tags are small glass capsules that encase a very small microchip that provides a unique serial number to each tagged fish. Once tagged, the fish can be scanned with an electronic PIT tag reader which display’s the serial number thus providing the fish-specific identification number. CWT are small magnetic steel tags that can be inserted in the fish via rostrum or underneath a scale (scute) and detected with handheld metal detectors known as wands. Generally PIT tags have come in one size (12mm) however a new smaller PIT tag (9mm) has been developed and may provide a new option for tagging of smaller fish. CWT have been used to tag smaller size fish however with the PIT tag an individual fish can be tracked and accounted for, as opposed to just identifying a single lot of fish (CWT). All fish were scheduled to be rechecked one month after tagging to get a good grasp on the tag retention of each tag type and size.

The staff at the Genoa National Fish Hatchery would like to thank the members of the FWCO offices, La Crosse Fish Health office, and members from the Menominee Tribe for cooperating in the tagging study.

Contact Info: Aaron Von Eschen, 608-689-2605, aaron_voneschen@fws.gov
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