Fish Asphyxiation

The photo on the left is of a salmon suffocating from being out of the water too long. The photo on the right is of the same fish after being resuscitated for almost four hours. Note that the color of the salmon returns much the same way humans do after turning blue from a lack of oxygen; it is the number one reason it's imperative that fish be put back as soon as possible if it is meant for catch-and-release.

Look at this lunker. I landed this huge Chinook with a ten-pound mainline and an eight-pound leader. It took me one hour and fifteen minutes to land this monster. It was not my intention to fish for kings, but it’s something that happens now and again when fishing for early Coho in rivers that have Chinook you better believe the possibility is there. Take a good long look at the photo on the left. In a cursory capacity I’m sure that most would agree that it looks like a pretty beat up fish. The fish on the right looks like a very bright Chinook. It has all the attributes that anyone could hope for, it’s chrome, over thirty-pounds, and it put up one great fight. The most remarkable thing about these two fish is that they are literally one in the same. You heard me right; they’re the same fish. It was suffocating and I didn’t even know it; but this fish was about to teach me a lesson I would never forget. It taught me about fish asphyxiation.
The condition of the Chinook on the left is based on the amount of fight time that I spent with him and the fact that I had him out of the water for some time. Since it was a native and looked as though it would still be a good fish to eat I didn’t intend to let it go so I strung him up and placed him into some low running riffles next to where I was fishing in an effort to keep him as fresh as possible.
As the hours rolled on by and I continued to catch and release other fish the one on the stringer was recovering from the battle that he and I had had. At some point while I was releasing a fish I heard a great commotion coming from the direction of where I had strung up the fish. I thought that it was going to get free so I ran over to it in an effort to stop it. I had seen other fishermen in the past lose fish that were poorly strung up and based on the amount of splashing that was going on I prematurely assumed that my fish was about to do the same. When I got over to him I was surprised that his color had changed so much that if I hadn’t been right there the whole time that I would never have thought that it was the same fish, but it was true. I was intrigued at its ability to recover so completely. Had he not resuscitated so thoroughly I would have never known that he was as bright as he was and that I was ready to dismiss his condition when I had initially pulled him out of the water as being mortally wounded which is why I intended to keep him in the first place. The parameters of the conditional retention had changed, that is, because the fish had so completely recovered I felt obliged to do my best to make available the opportunity for the fish to go back into the water. Not only had this fish afforded me a fight of a lifetime, but he had shown me the way to understanding that given time, many fish can recover from asphyxiation even under the most sever circumstances.
Four more hours went by before I thought that he was well enough to go back into the water. Even though I profess routinely not to string up a fish and put it back simply to avoid accidentally killing the fish, this one seemed to avoid all mortally wounding contact and I was blessed to have gone through it with him, I knew that he would live if I were extremely careful with him. At a painfully slow pace I removed the stringer making sure that the line did not touch any part of his gills. As I resuscitated him back and forth I checked to make sure that he was not bleeding. I maintained the idea that if he had received a wound to the gills I would put the stringer back on him and take him home. He was not injured so I resigned myself to putting him back. I opened my hand and he swam away with the same kind of vigor of a fish that had never been hooked, landed, suffocated, and strung up.
I’ve always looked upon the experience as an experiment that might never be repeated; to do so would involve risking the welfare of any fish I intended to release and would be down right cruel to subject a fish to suffocation I might take home. In either case since then, I take care to ensure that each fish’s head remains in the water for as long as possible prior to taking a photograph and take the time to fully resuscitate every fish I put back in the water by grabbing the tail-wrist (Peduncle) and holding the fish with an open palm on the belly (Visceral Cavity) and point the fish in direct current and wait for it to revive. As it gains strength I loosen my grip on the tail and let the fish swim off under its own power.

Make sure to take the time to let each fish fully regain its strength. Note the position of my hands: one at the tail and one under the belly; both are "Lightly" clutching this fish as I move her back-and-forth in the direction of the current. To ensure adequate oxygen, you must remember to point the head of each fish directly into the oncoming current. By fully resuscitating a fish anglers ensure the survival and propagation of each species. There’s no need to take such precautions for fish you intend to keep.