Rises

Roberto: The first time I read about the different ways a trout rises to a fly, I was blown away. Can you really tell what a trout just ate by the trace it leaves on the surface?
Antonio: If you analyze the distortion on the surface, observe the insects present in the water and patiently let the trout rise a few more times, you may be able to know. With a certain margin of error.
Actually, that table for interpreting rises is more illusory than practical. But there's a lot of that in fly fishing.
Roberto: Isn't there anything you can take for certain in observing how a trout rises?
Antonio: Maybe the most reliable thing is the relationship between the noise and the size of distortion created together with other parameters, such as the movement of the insect, the size of the trout and the speed of the water.
Roberto: What do you mean?
Antonio: The more the insect moves and the faster the water, the greater will be the splash. But the larger the trout, the more subtle the distortion and noise. In short:

Little trout + moving insect + fast water = SPLASH!
Big trout + still insect + slow water = Sip.

Catch and Release

Roberto: I've been doing catch and release ever since I started fly fishing. But I never expected it to put my former trout-killing fishing buddies so out of joint.
Antonio: That attitude reminds me of smokers. They'd love to quit smoking, but they're not at all pleased that their smoke bothers you.
Roberto: Putting fish back has become a kind of religion with me.
Antonio: To speak of catch and release as a philosophy or a religion is pure nonsense. Philosophies and religions are about much more complex vital issues. Catch and release is only about wanting to go on catching trout. The rest is something we make up because, when you come right down to it, fly fishermen are a little batty. Defending catch and release with ecological or existentialist arguments alienates us from clear, direct dialog with those that practice catch and eat.
I think we should flee from those approaches and stop beating around the bush; I-release-because-I-want-to-catch-it-again is the only real argument. Catch and release should be seen more as a management tool than anything else: It's the only one that's proven its effectiveness so far.
Roberto: I've been called a sadist for making them suffer again and again. But I don't think they feel pain.

I feel that you feel

Antonio: It's nice to believe what one wants to believe. It often helps quite a bit.
Roberto: Well, do they suffer or don't they?
Antonio: Two recent studies carried out by prestigious universities arrive at almost opposite conclusions. One shows that they clearly feel pain. The nerve endings and chemical changes in a hooked fish's organism while fighting to break free indicate this. The other concludes that the psychological component of pain isn't present in fish and, therefore, it can not be asserted that that they indeed feel pain, at least not as we understand it.
Roberto: What do you think?
Antonio: They're both right.
Roberto: In other words, maybe they feel pain; maybe they don't.
Antonio: Well, let's apply a little commonsense. The trout is a species that's been evolving for thousands of years. Pain is a defense mechanism that all species have to protect themselves and detect problems in their organism. When you hook a trout, it acts as if it weren't too happy about it. You take it out of the water and it starts suffocating until you put it back. Call it what you want, but I assure you the trout isn't enjoying it. It's clear in my mind. The fisherman makes the fish suffer.
And yes, catch and release has overtones of sadism. Killing them has overtones of murder.
Roberto: But some trout bite again shortly after being released.
Antonio: True, that happens sometimes. It's as if the instinct of aggressiveness in some trout were much stronger than that of defense. At any rate, that's an exception.