This spring Iron River National Fish Hatchery elastomer tagged two additional brood lots of coaster brook trout; SSW 05 GEN (Siskiwit Bay strain isolated at Genoa NFH) and STW 04 (Tobin Harbor strain reared at Iron River NFH). 

The fish were tagged with elastomer on both sides of the lower jaw.  As spawning began in the fall, a full inventory was again performed on both groups of tagged fish.  The inventory revealed 92%of the STW and 93% SSW coasters retained visible tags.

An ongoing inventory of the STW 04 GEN (Tobin Harbor strain isolated at Genoa) tagged in the spring 2006 is also being performed.  While initial glances at the fish seemed to show no tags present, they popped into view and fluoresced under the VIE flashlights.  To make life easier while spawning, our lifesaver, Duane Simpson (Wisconsin Experience Works employee) was able to come up with a stand to hold the flashlights. 

This allows staff to quickly check the fish for tags under the light without the help of an additional person holding the light.  To date, 464 fish have been spawned and of these, 270 fish still have visible tags (58%).  The breakdowns are as follows:  tags in the adipose eyelid had 46% retention, tags in the upper jaw had 57% and tags in the lower jaw had 72% retention. 

This group of fish was tagged in three locations and with three different colors.  This initial study helped to determine the location and colors that were easiest to see, tag and which retained the tags the best.  Plans are now in the works to tag two more brood classes and two production lots this spring. 

The fish will be given just one clip to denote the strain of the fish and the year class will be distinguished by the color of the tag.  This has now helped to eliminate the need for clipping additional fins to keep year classes separate, the fish are reared together in one raceway for each strain.  The tagged production yearlings will be stocked into Whittlesey Creek later in the spring/summer.