A friend passed the following info on to me. I'll submit it to the BB not as judgement on anyone but for informational purposes only.

"catch and release is important, but there are some guidelines to keep in mind. Most C&R advocates reconize the importance of barbless hooks, but too few seem to understand the importance of keeping fish submerged.

A study at Queen's University in Ontario examined the effects of exposure to air on trout after exhaustive exercise. The study showed that exposure to air after a tiring experience, even a brief exposure to air, significantly increases the mortality of released trout. When lifted into the air the lamellae (oxygen gathering part of the gills) collapse. When lamellea have collapsed they no longer can absorb oxygen.

The effect does not show up immedately, so a fish lifted from the water for a picture may look healthy and happy and swim away. However, over the next 4-12 hours the fish slowly suffocates.

Here are the terrible numbers. An exhausted fish lifted into the air for 60 seconds has only a 28% chance of survival! If lifted from the water for 30 seconds, the rate improves to 63%. If not lifted out of the water at all, survival is 88%.

The important lesson: DO NOT LIFT FISH OUT OF THE WATER!

Catch and release is an important part of sustainable fisheries, but it must be done correctly. It is not enough to dump the fish back into the river after hauling it out. Trout are fragile beings and connot survive the abuse of being removed from their aqueous enviroment."

Thanks for the study data Sloth! This has been a board issue during nate season in Oregon- so I will post your info. there too. Anything that will help them survive C&R is appreciated.- Steve

Good study info

Try running a marathon then hold your breath for a minute

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Marty
www.steelheader.net
marty@steelheader.net

Interesting findings, although I have several questions:

What species of trout were used? Were they residents, or large anadromous fish? What were the air temperatures? water temperatures?

The reason I ask...there is a large difference in the size of individual gill fillaments between a 12 inch resident trout and a 10 lb steelhead. I would think the incidence of clumping could also be different and not as severe, the larger the fish.

I would be interested to here if some of the private trophy lakes, where catch and release is the norm, have experienced mortality rates this high. In such lakes, I would think that dead fish could be found and tallied much more readily.

I confess I haven't thoroughly looked at the body of literature on hooking mortality, but it is my impression that most have been conducted on resident trout populations. I am aware of 1 series of studies conducted a few years ago on Atlantic salmon. These studies found hooking mortality ranging from 3 to I believe 18 percent. Double digit mortality all occurred when water temperatures exceeded 60 degrees--i.e., August/September type conditions. At those temperatures, the fish can over burn itself out, and warmer water holds less dissolved oxygen, making recovery even more difficult. Data on length of time out of water was not collected in these studies.

In the study you mentioned, the hooking mortality of fish not lifted out of the water was 12 percent (88% survival), which seems pretty high. This makes me think the study was conducted on small resident trout. The smaller the fish, the more damage a hook can do as well.

At any rate, a good warning to take your hero pictures quickly and release the fish. And please, don't pass the fish around to all your buddies so they can get a picture with it as well. This is a real eye-roller.

[This message has been edited by obsessed (edited 03-10-2000).]

[This message has been edited by obsessed (edited 03-10-2000).]

[This message has been edited by obsessed (edited 03-10-2000).]