Catch and Release during spawning

[jero]

In my fishing waters its legal in some rivers to fish C&R during the spawning season, wich ocurrs here in late autum, winter and spring. Any studies regarding the impact on the trouts health and reproductive capacity? My uninformed guess would be that the fish should be left alone. And somehow I have the feeling the local flyshops and fishing shops here have pressured the government so they can keep un commercial activity during the off-season.
any real evidence supporting either claim?

[juro]

You said trout but I believe some species (e.g. smallmouth bass) have no problem with it provided the scavenger species do not exploit the nest during the battle. I've seen the same fish on the redd weeks apart, and admit I caught the guy repeatedly when I was a kid and had less scruples about it.

Trout on the other hand are much less hardy than the basses and I am not sure the survivability is nearly as high although most evidence I have seen indicates that C&R fly (no swallowed bait) is not all that harmful. There were studies on tagged release trout to track their movements and the were obviously fine.

Steelhead and salmon are pretty hardy within certain tolerances, like keeping them in the water and using single hooks, etc. They make a journey of thousands of miles against waterfalls and defeat serious adversity along the way.

However without any scientific basis I could just be rationalizing my own interest in the sport. I'd be interested in statistics and research materials on this subject to try to be objective about it.

[jero]

sounds reasonable Juro. I been fishing C&R this offseason (south hemisphere) almost every weekend, but I´ve been a bit curious lately with the subject. Even though in my life more than one trout has ended up in my stomach, I wouldn´t feel comfortable fishing during spawning season if I found out I was doing too much harm.
cheers