🚀 go-pugleaf

Andrew,

I've done some work with the Nevada Department of Wildlife marking
Woundfin minnows in the Colorado River with coded wire tags from Northwest
Marine Technologies (360-468-3375).  To tag the fish, one injects a
microwire (about 1 mm long and .25 mm dia.) into the fish with a hand-held
injector gun.  One then can detect tagged fish using a hand-held wand
similar but more sensitive than the hand-held metal detectors used in
airports.  It is difficult to differentially tag fish with this technique,
unless the fish is big enough you can tag some in the snout and some in
the tail, or you can tag on one side or the other.  However, it sounds
like you just need to know presence or absence of tags to tell if the fish
is hatchery reared or not, and this technique works well for that.  The
only downside is the expense of the equipment, which is about $10,000 for
the hand-held injector and wand detector.  You may be able to find a local
agency who owns the equipment and may be willing to let you borrow it.
The consumable tags are very inexpensive ($30 for 10,000 or so).  Good
luck.

Mark Sappington

Dept. of Biology
Univ. of Nevada, Las Vegas
sapping@nevada.edu