Baro-trauma

That is all pretty good input. I appreciate mako1 for asking the question and others for answering because I never fished deep much before this year and if I can fish shallow I will, but if it's legal to fish deeper and nobody is catching shallow I may exercise my right to fish deeper.  and I am going to release a few gophers.

SC, it seems a small stomach puncture must happen time and again with all the stuff they eat (have you seen what they puke up? whole crabs, etc). I have also been told by a poison hotline doc (actually our own Alan T.) that the intestinal tract, at least in humans, is very quick healing and so that is why people can live after eating glass and some of the other stuff that ends up going through there.

So I got to believe that a few of those fish are going to survive a stomach lining and bladder puncture, if it is relatively small and done with some care.

However, it is very true that I just decided to do this on my own during a gopher plague and saw that they swam down with clear, intact eyes with a little help from the heavy de-barbed jig head, and a very small hole in their insides and a bigger hole in their lips and I am betting the majority are still happily eating nasty little bottom dwelling creatures.

the only fish I have released from deep water are coppers which often seem to have no barotrauma and gophers which look okay, but have trouble swimming back down (they get stuck at about 8 feet down it appears), and lings which have no swimbladder.

I have learned that tipping with squid and deadsticking the bait very near the bottom is a big invitation to gophers. 

I've used Sheltons descender since it was a prototype, on LMB and spotted bass when dropshotting Lake Oroville. It really does work. It is cheap (~$4) and small enough to always have in your tackle box. I never felt right piercing a hole thru the body of a bass to deflate the swim bladder and C&R deep water bass is just wrong. They just float back up and become pelican bait.

I've used the SFD on a PB fishing for rockfish, it worked good and allowed me to safely releasesmaller rockfish so I could get larger fish. I would rather whack 2 larger fish than a limit of smaller fish.

That Git 'er down thing is like $75 and too big for a yak.

I've tried all the techniques mentioned in this thread and have recently decided to keep any injured fish that I catch. I don't know for a complete fact that any technique works 100%, so I'd rather swallow my pride and end up with ten gophers in my bag and maybe I'll feel better about it in the long run. Fish big jigs and hope you get slammed. Sometimes the shrimp fly teaser is catching a lot of big reds, so you're bound to get some pinner fish with that too. And those really small ones that have eyes bigger than their stomachs make nice ling bait. I don't want to come off sounding righteous and preachy, I've left too many floaters in my own time, but it's the long term  that we're looking at here.
                                     CoS