The elastomer is injected as a liquid just underneath the skin and eventually cures to a pliable solid tag in the fish. - FWS photo

 Staff from the Iron River National Fish Hatchery elastomer tagged two more brood lots of coaster brook trout in April. 

On April 10-11, a total of 940 Tobin Harbor strain coaster brook trout received an orange tag in the lower left jaw and blue tag in the lower right jaw and 580 Siskiwit Bay strain coasters received a pink tag in both sides of the lower jaw. 

On July 2^nd, a full inventory of both strains was performed.  The Tobin Harbor strain coasters showed 75% of the fish retained full tags on both sides of the jaw and a total of 93% retained at least a full tag on one side of the jaw. 

The Siskiwit Bay strain coasters showed 60% of the fish retained full tags on both sides of the jaw and a total of 90% retained at least a full tag on one side of the jaw.  These fish will be inventoried again during spawning this fall to see if there is any further loss of tags. 

Biologists are continuing to study how long the tags remain visible in the fish to someday begin using this as an alternative to fin clipping in brood fish. 

Iron River National Fish Hatchery maintains multiple year classes and strains of fish in limited space resulting in multiple fin clips.  The first coasters were tagged in March, 2006 and after nine months an inventory showed 70% retention.