Here is a really good article about barotrauma, one of the best ones I have seen talking about multiple aspects
gf.nd.gov/magazine/2021/jul/understanding-barotrauma
The most relevant excerpt:
Some fish are more susceptible to barotrauma than others. Fish like trout, salmon and pike have a duct that connects their swim bladder to their stomach, allowing them to “burp” air to decompress their swim bladder as they are brought up from the depths. Meanwhile, fish like walleye, perch or bass do not have this duct and regulate their swim bladder by releasing gasses through the gills via the bloodstream (similar to how a human lung exchanges oxygen and carbon dioxide in the blood). This is a much slower process, and results in the bloated appearance of the swim bladder when a fish is reeled in from deep water.In numerous studies across North America, largemouth bass, smallmouth bass, walleye and yellow perch have exhibited increased mortality due to the effects of angling barotrauma. The depths of those effects varied depending on the study lake or fish species, but in general most studies have shown a dramatic increase of mortality when depths exceed 10 meters or roughly 33 feet. Coincidentally, 10 meters generally corresponds to the depth where the pressure under water measures one atmosphere.
Hmm regarding angler "BS" as southshore put it...
Regarding releasing fish by "fizzing", I think I may have written this on here (or maybe facebook) before, but essentially the premise is that you poke the swim bladder to vent the gas. The issue is that a lot of untrained people are poking the stomach, or other internal organs, and just causing more damage. Best case scenario, if you poke the air bladder with a needle, you are releasing that pressure so they can swim back down to depth and re-pressurize. That's all well and good, but getting the fish back down to depth only corrects the swim bladder issue and blood gasses. It's pretty hard to put the toothpaste back in the tube, as it were, for hemmoraged organs, eye damage, etc. Not to mention that if you poked a big hole in the air bladder or stomach, it has a hole in its organ to boot, and may have issues regulating buoyancy and/or eating. And probably most importantly, just because the fish swam away and out of sight doesn't mean it was fine - it can die a few hours to days later.
Other things I have heard - reel the fish up slow! As someone who's done a fair amount of scuba diving, this one always makes me roll my eyes. These fish have been at that depth/pressure for a long time. Days or weeks, most likely! Your bottom time scuba diving at 50 to 60 feet without a decompression stop is in the ballpark of an hour. Longer than that and you have to add a decompression stop and hang out for say 15-30 minutes halfway up (i'm simplifying here, I haven't looked up the calculation on a dive table). To actually avoid barotrauma you would probably have to take about 30 minutes to reel a fish up.
My personal rule fishing for walleye, perch, crappie, bluegill, etc over 30 feet deep is I am keeping them, as long as they meet any legal length requirements. I just can't in good conscience release fish that have a significant chance of dying afterward.