Thats funny you bring up this topic, I have been doing a lot of research involving "sub-lethal" effects of catch and release fishing. Sub-lethal effects are those that do not cause death, but still have a negitive impact on the fish. Two biologists named Steven Cooke and Cory Suski have written several good papers on the subject.

They explain that there are 5 main parts of angling that stress fish:

1)Angling time, or the amount of time you fight a fish- this is bad because they are using a different kind of muscle (white muscle) that is used for quick burst swimming and long fight times wear the limited energy stores in that muscle. Using this muscle tissue also increases blood pH and other waste products.

2)Air exposure- the gill structures collapse when not suspended in a liquid medium, and they wont function in air. They dry up and can become damaged. This also forces them to use energy stores that are useful in burst swimming because of the metabolic pathways used when oxygen isnt available.

3)Fishing during extreme high or extreme low water temps. Especially high temps. Just extra stressful.

4)Hook injuries- Some prevent a fish from being able to eat for long periods of time. Others can host infections.

5)fishing imidiatly prior to or during spawning - ruin reproductive success.

Other studies have shown that live well stress can reduce reproductive success and have long term effects on cardiovascular activity of bass.
Poor reproductive success means one or more of the following:

decreased quality of egg/sperm
decreased quantity of eggs/sperm
decreased parental care for eggs,larvea and fry

The last thing I will talk about is Deep caught bass. I am writing a paper on decompression effects on spotted bass, and if theres one thing I could get accross its that you should get your fish back in the water ASAP. there is about 3-5min before the swimbladder become hyperinflated, at which point the fish will have to be manually sunken down to deep water using the technique Rob has written about in this website, or "fizzed" using a 16-20 gauge hypodermic needle.

Mortality rates and reproductive success are high in deep caught fish, so keep that in mind when your pluckin spots out of 60ft. (unless you hate spots - Lake :P )

Just some helpful info that made me feel bad for being a fisherman when I read it haha. But really, just by knowing these things you will pay closer attention to details when you catch a fish, and will likely reduce the stress you cause the fish.