Fishery Biologist Adam Kowalski extracted and read coded-wire-tags (CWTs) from lake trout in November. CWTs are microscopic metal tags placed in the snouts of juvenile lake trout at the hatchery. 

Kowalski looked at sport-fishery caught lake trout heads collected by Michigan DNR creel clerks in Lake Huron and removed tags from lake trout sampled by the Chippewa Ottawa Resource Authority (CORA). 

CWTs are extracted by cutting lake trout snouts into smaller and smaller pieces until the tag can be seen and removed then  read under a microscope.  Each tag’s unique number can then be compared to stocking records to yield information such as stocking location, stocking date, fish age, fish strain, and hatchery of origin.

In total, Kowalski removed and read over 250 tags from approximately 300 heads. Not all adipose clipped lake trout contain CWTs because some lake trout shed their tag and others experience fin regeneration that masks original multiple clip sequences. 

Additional lake trout heads will be received from Bay Mills Indian Community (BMIC), the Michigan DNR creel program, and processed along with heads from the Alpena FRO fall surveys.  These heads will be processed when received.