I don't want to take away from the livelihood of those who manage ponds and sell good products for taking care of fish. I did wonder at the $62 price tag for the gun.
Saw this on ebay and it looked like it might just work. Not sure how much power it would take to inject the tag through the fin but probably if it can tag a sweater or pair a jeans it might work?
Would have to live with clear tags though.
Clothes tagger
