ODFW researchers are evaluating a range of fish marking methods using Oregon chub.  Visible Implant Elastomer (ViE:  an injectable colored plastic) was found to produce an effective mark.  Vie was used successfully to document fish migration patterns in 3 river sub-basins.  The VIE marks persisted for at least 3 years.  Resource management and recovery operations need a way to track the movement of free-range fish.  This requires a method of tagging or marking the fish-- however, reliable methods to track smaller fish are lacking.

Bangs, B.L., Falcy, M.R., Scheerer, P.D. and Clements, S.  2013.  Comparison of three methods for marking a small floodplain minnow.  Anim. Biotelemetry 1(18).