Jed, you bring up a good point. Pollutants are a problem in many areas, and eating fish isn't a good idea. That's kind of a problem here where I live. We don't have trout, it's all warm water. This area was a big part of the steel industry at one time, and the entire Mahoning river system was polluted as a result of that industry (and others).
The steel is mostly gone these days, but the damage these companies (and others) did for so long is still with us in the form of mercury and other contaminates. I won't eat fish around here due to the warnings put out by the ODNR. I release everything I catch, unless I plan to keep a specimen for the aquarium.
So for me, I release fish more out health concerns than anything. I do like to eat fish from time to time, but only store bought these days. Bluegill, Yellow perch, and walleye are awfully tasty though, and I'd keep some if I didn't have a fear of being poisoned.

J.