Extremely HOT Topic

[Sixshooter]

What I am asking is for some proof. Not just opinions on the matter. An opinion is okay as long as there is PROOF behind it for this question.

A HUGE debate in great lakes fishing is if released fish survive or not!

What I want to know is where is the proof that a fish absolutely dies after you release it? How do we know? Is there some studies out there that prove this? It seems to me that Butch had a study on the subject that said they survival rate for a salmon was over 80%.

I'm just very curious as to where/how this conseption of if you catch a salmon it is going to die came about. Is it just hear say and we believed it and ran with it because to us it made sense?

Your pulling a fish up out of deep water it is warm the fish builds up lactic acid gets a charlie horse and dies....I don't know of anybody that has died due to a charlie horse...Might be sore for a few days but that is about it.

Is there any hard facts to base the opinion on, or is it just because it is something we have heard. Because frankly I don't see that many dead fish floating around while fishing.

[Catfishhoge]

Very good topic Jim, I agree that you don't see many dead fish floating. There will obviously be "some" mortality among the released fish for specific reasons. I have not seen or looked for a study on the matter.

Interesting topic for sure!

Rick

[Steve Arend]

An article that I read a while back.

Catch & Release of Large Fish

[Reel Turner]

Great article Steve. I did some research on the mucus loss and mortality in yellow perch college and found no effect based on temperature difference and turbidity, so I would agree it has little to do with handling of the fish, within reason. However, none of the studies referenced indicate a releationship between mortality and extreem temperature changes. Most fish will be significantly stressed (alot of time to the point of death) by extreem temperature changes in the surrounding environment (i.e. pulling a salmon from 48 degree water to 70 degree water on the surface). I am sure this stress is reduced depending on the time of year and the actual temp change. I wish I still had access to scientific journals so I could site some articles. I am excited to see some other facts.

[Sixshooter]

Good article Steve. That is nice Salmon over 18 inches have around a 90% survival rate when released.

I don't recall if that is the same article that Butch posted on or not. I can't seem to find it. Perhaps if he reads this thread he can add to it.

[Steve Arend]

One other thing that I have not seen mentioned in any studies that I have read is Mortality do to quick changes in water pressure.

A fish that is stacked in a 60 ft water column has around 25.98 lbs/in2 of force been applied to that fish. Now you bring that fish up to atmospheric pressure which is 14.7lbs/in2 @ 32 deg F. You are reducing the force applied to that fish by half with in a matter of minutes before that fish has time to adjust to the lesser pressure. This has to put a lot of stress on a fish mixed in with the changing of temps.

[Mrs. Sixshooter]

Here's a few articles I've found regarding this topic.....

http://www.cfb.ie/fishing_in_ireland/CatchandRelease.htm

and a question answered from Michigan DNR

http://midnr.custhelp.com/cgi-bin/MiDNR.cfg/php/enduser/std_adp.php?p_sid=jDDHvB5i&p_lva=&p_faqid=1321&p_created=1026780064&p_sp=cF9zcmNoPTEmcF9ncmlkc29ydD0mcF9yb3dfY250PTMmcF9zZWFyY2hfdGV4dD1jYXRjaCBhbmQgcmVsZWFzZSZwX3Byb2RfbHZsMT0yJnBfcHJvZF9sdmwyPX5hbnl_JnBfcGFnZT0x&p_li=

[Sixshooter]

Good find Wife. That is interesting news from the Michigan DNR.

I was wondering where the path of this thread would take us. So far it is very supportive that you can successfully catch and release fish in the great lakes.

Is there dispelling proof out there to deter us from such activities, and nobody has found them yet?

I know I've been told many times by some very good fisherman that releasing fish they will die even if they swim away. Of course I have to look at them funny and I move on....I don't neccissarily believe them they do...and so far I'm thinking they were just going on something somebody else told them.

I know there is more information out there and I hope it comes to this thread. Thank you guys and gals for keeping this on track...A topic such as this one can so easily get out of hand with the matter of everybodies opinions.

[Sixshooter]

One other thing that I have not seen mentioned in any studies that I have read is Mortality do to quick changes in water pressure.

A fish that is stacked in a 60 ft water column has around 25.98 lbs/in2 of force been applied to that fish. Now you bring that fish up to atmospheric pressure which is 14.7lbs/in2 @ 32 deg F. You are reducing the force applied to that fish by half with in a matter of minutes before that fish has time to adjust to the lesser pressure. This has to put a lot of stress on a fish mixed in with the changing of temps.

Steve what is atmospheric pressure at 70 Degrees F? I'm assuming the air pressure as well as wet pressure are all relative to temperature...

[GLF]

Steve what is atmospheric pressure at 70 Degrees F? I'm assuming the air pressure as well as wet pressure are all relative to temperature...

I am a certified scuba diver. The underwater atmospheric pressure is what really needs to be taken into account. There is a huge change in atmospheric pressure underwater.

Underwater, pressure increases by "one atmosphere" (the equivalent of atmospheric pressure, or 14.7 lbs./sq.in.) for every 33 feet we descend into the water. This means, for example, that the pressure at 66 feet below the surface is 44.1 pounds per square inch, or three times that of the atmosphere.

It takes more air pressure the deeper you go. As you ascend in water air expands. This is why you see a perches belly come out its mouth when pulled from 50 ft of water. I have never seen a salmons belly come out its mouth. I am not sure if fish get the bends or not.

The above test article does not mention about which depth the salmon were caught. The pictures in the article only show streams in the back ground.

I would venture to say the mortality rate is higher than the articles.

I am not an marine biologist and these are only my views.

[Sixshooter]

I don't know the answers Mike....But a Salmon is definatly built differently than a perch.

Lets not forget that Salmon are originally from the Salt Water Oceans that dropp Miles and Miles and Miles deeper than our great lakes.

I would not be suprised if the salmon was built for quick changes in wet pressure.

I've read articles of the guys trolling for salmon on reefs that are 2000 feet under the surface.

Many predators in the ocean such as sharks will hang out in 60+ FOW and hug the bottom and watch the anchovies or whatever swim just below the surface. They will torpedo straight up and crash the bait on top.

there is some incredible footage of watching Great Whites do this with Seals and Sea Lions....They don't seem to die when they have sudden pressure changes.

But then again that is a difference between a salmon and a shark and their swim bladders.

There is also evidence of catching walleyes in Dakota on Devils lake where they will catch these fish in 60 FOW. but the release them just fine. But they use a technique called fizzing. They use a needle and insert it in a certain spot to deflate the air bladder, because it expands with the rappid pressure change. Once it is deflated the fish can go back to normal and keep itself right side up. But walleyes are not in the same hunting class as a salmon. nor are a walleye a fast swimmer...

You are right though most of the evidence so far would lead you to believe it is stream or river type fishing. Although the DNR report is VERY intriguing. I'm curious to read more on the topic.

[GLF]

I have seen the fizzing technique used on bass also. What would be a neat study is a radio tracking of salmon caught(50' or deeper) and released to see what happens.

[DangerDan]

I can garauntee that every fish that is caught and released (no matter how much care is taken to preserve it's life) will die!!

[DangerDan]

Eventually.....

[HitMan]

I have a few thoughts on this matter. Can you successfully release a Salmon that you have netted without any scales falling off? Do your hands remove some of the slime on a Salmon? Salmon can be successfully released if they are not touched and hurt. If you catch a Salmon in 50 degree water and then try to release it in 70 degree surface water, do you think it would get shocked while missing some of it's scales?

Salmon are very delicate when compared to a bass or perch, etc. This is a very debatable topic and has been discussed with numerous DNR biologists and NOAA biologists at a lot of the Charter Boat and Sea Grant Meetings. Most will say Salmon initially get shocked, but they do not die instantly and many do survive. A lot of the fish survive and a lot of the fish eventually die. This topic is brought up at almost every DNR meeting.

For those of you who have never seen A LOT of Salmon floating, I would recommend riding around Lake Michigan during the South Haven Tournament. This is the most controversial tournament on the Great Lakes. In 2004, we caught 29 Salmon on Saturday and 37 Salmon on Sunday. You have to catch 9 Salmon and 3 Trout there, when the catch is 99% Salmon only, especially in Southern Lake Michigan in the SPRING!!!!!!!!! We counted at least 20 fish that floated away directly behind our boat and counted over 100 fish that we passed floating while trolling both days. The numbers were even worse and higher for 2005 during the tournament.

[Sixshooter]

Answer me this question if you will. Do all these "tournement" boats take the time to revive fish they throw back? Or do they unhook the fish and toss it over the side as quick as they can so they can get another rod down right now?

My guess is nobody is "waisting" time to revive the fish.

That is sad to here that fish are dying needlessly for the sake of money...Perhaps the contestants should protest the tourney if it is so bad...but that is for another topic.

[GLF]

Hey Jim, ever wonder why Lake Trout poop all over your boat?

Because they can

On a more serious note. Maybe it has to do with the air expanding inside them from being brought to the surface and forcing it out.

[HitMan]

It is a very sad event, with a very clueless committee. The first year it really started to happen, 2004, about 5 of the Lake's best charter fishermen approached the committee on the Wednesday before, during prefishing, and told them the rules need to be adjusted because our Charters are only lasting for 1 hour and we can catch 18 Kings in that time frame. For the tournament it should be catch 12 fish and go in immediately. Well they ignored that and said at the Captain's meeting everyone should have fun as we expect almost every boat to catch their limit of Salmon and the hard part will be getting their Trout. Well I already told you the effects of that year.

Well that year and summer and winter all everyone did was talk about the South Haven Tournament; and then they followed it up with the same rules in 2005, but now without an observer for the Pro Division.

Guess what the rules are for 2006?!?!?!?! Same exact rules with no observer again. Three years running now and the amount of entry boats increases every year. You can email the committee, call, talk in person, and they frankly don't listen to what you have to say or your input at all.

I can bet you almost every person doesn't try to revive a Salmon during a tournament. You are paying money to win money. How many people would try to successfully release a Salmon when money is involved, especially when it is bigger than some you already have in your cooler? Our boat looked like a slaughter house with blood and slime and guts everywhere from so many fishing flopping around. Plus, in 2004 still, you had an observer sitting there making sure all those fish got tossed back and there wasn't any cheating or miscounting or anything else going on. We had caught our 9 weighable Salmon in the first 47 minutes of the Tournament. It is bad enough we are forced to stay out and catch 20-30 extra fish because the committee says we have to. Here comes in their other great rule, you can not go in early unless you have your 12 weighable fish and if you do, you will be DQed, same as getting towed in, etc.

Anyways, it is very hard to release Salmon successfully without them being harmed. Larger Salmon it is even harder. Small Salmon can easily be released with a pliers and a flip of the wrist. Once you begin netting Salmon is when they become fragile and lose scales, slime, and life.

[HitMan]

Anyways, enough of the releasing Salmon subject for me. It gets me too revved up and stressed out,

[Butch]

I'm not a scientist, but I've read quite a bit on this subject and have made some extensive personal observations on the subject of mortality of released fish.

Sixshooter asked whether the excellent article posted by Steve A was something I'd referenced before; the answer is "no". I recently posted a cite to a MDNR study on survival by released lake trout. That study found lake trout survival was well over 90% if the fish were not bleeding badly. I thought that was interesting because "everyone" had told me that lake trout that are pulled up quickly from deep water rarely survive and because I've observed them with swim bladders expanding into their throats and floating after release myself. When I get some time I'll try to dig up the cite, but I'm pretty sure the abstract to the article is available in the research section of the MDNR website.

Most of the research I've seen on this subject is based on fish from rivers but there is lots of evidence about fish survival out there. As mentioned above, hooking injuries are the biggest problem. As I recall, the science on this is clear. The biggest cause of mortality is hooks in the gills or gullet, then hooks in the tongue(if it is badly injured or becomes infected they can't use their toothy tongues to hold prey) or eye. However, even gillhooked fish can survive, just at a much lower percentage. I've even caught a few trout with an entire gill torn loose and hanging out of their gill plate, but healed over. And lots of trout survive deep punctures from kingfishers, herons and otters, and in some of the studies the fish must suvive removal from the water while a transmitter device bigger than a AA battery is surgically implanted in their body cavity.

Loss of slime is not a big issue, healthy fish not living under stress can quickly regenerate slime. I've talked about this with fish biologists and they laughed about the slime issue; in the hatcheries during egg taking they wear dry cotton gloves to more easily grip the fish and strip the eggs and milt. Obviously they don't want to harm their brood stock, and they would observe it if their brood stock were dying of fungus or infection from loss of slime.

Lots of people have told me that even if they swim off, they are likely to die later. Some do, but most of the studies show that fish that swim off and aren't suffering from severe hook injuries do not die later.

Lots of studies document that temperature is the biggest factor other than hooking injuries. Over about 68 deg. F, a much higher percentage of released fish will die. Again, most of these studies are on rivers, where cool, oxygenated water is not readily available. However, even on this issue, in the big lake a fish can quickly swim back down to cooler/more oxygenated water. I've never read a study on this, although I've routinely seen released salmon swim straight down immediately after release. Of course, if the fish at at the river mouths in warm water top to bottom, this isn't as beneficial.

I've also released hundreds of large stream browns in water over 68, often after fighting them to near exhaustion on fly tackle. I've kept extensive records of each large trout I've released, and for over 5 years I carefully marked the large trout I released. In my personal observation, many will be back feeding the next day, and the next year. Many disappear, but some move(I've found them miles away and most of them move at least 50 yards from where they were caught), and virtually all are educated to the point of becoming more difficult for me to recatch. Some undoubtably do die, but as mentioned above, they all die if you stick a fillet knife into them.

If you want to release them on the big lake after netting them, of course you could stop the boat and hold them while they revive. If you don't want to stop the boat or your gunwales are to high to reach the water, I suggest that you take a lesson from the muskie guys. Remove the hook as quickly as possible, cradle the fish in 2 hands, and launch it upright and head first back into the water. They get a quick rush of fresh water over their gills and get through the surface turbulence. Some will float, but even many of those will revive and swim off. If they are bleeding badly and it's legal, keep them.

[GLF]

Very informative post Butch. Thank you.

[Adjusted3]

I wil dig out some stuff that I have collectd over the years. It is on another computer at home.

I now that Spanwalker has a nephew, Prof Trent Sutton that may able to help us. Maybe Mike could send him this thread in an e-mail and get his insite. Trent is a very well respected fishery bioligist for our great lakes and is currently teaching at Purdue.

Mark

[Reel Turner]

Trent is a great guy. I had him as a fisheries prof up at LSSU. Last I heard he was at Purdue, we might be able to find a contact e-mail there.

[Sixshooter]

Thanks Matt.

I also remember several years ago In-Fisherman did a study on the catch and release of fish and how it effects them. They stated that a fish released into water that has a current recovered over twice as fast as a stagnent area.

And as we all know there is plenty of Current in Lake Michigan. In fact there is more down there than many realize. They stated it was, like Matt said, Fresh oxegenated water being basically forced through the gills of the fish, with the fish exerting minimal effort.

I would be interested to see what the biologist at Purdue has to say. But as of yet nobody has given scientific data that if the fish is handled and released correctly that it is for sure going to die like I have been told many of times.

Matt that fish hatchery story is great. And very true. Just think if all the wild strain steelhead in the little manistee river died because they used cotton gloves and STROKED the eggs and milt out of the fish....I never thought about that before.

[Treblemaker]

I'm in agreement with Hit Man on this one. These guys are on the water daily and see first hand what can happen over a much larger scale than us part timers. I have also heard from the many captains who expressed their sickening of these tournament practices and have lobbied for change for the good of the fish and fishery.

I have released many fish and they mostly seem to swim away and some have floated. If it is a legal fish why not keep it? When money and egos are on the line mainly, unless we are just fishing for fun not to keep anything. But all would agree that at least some of these fish will not make it. It comes down to an ethical debate in the end, mainly dependant on whether one thinks the fish will "make it". If we knew they would die would we release many? Or throw back dead ones to upgrade to a nicer fish? I don't think so.

Even our DNR plays devils advocate by the 3/2 limits they set. By only allowing 3 kings or fish of any species you must continue to fish to catch a full DNR limit. Many times the kings or coho are prevalent and even after switching programs for other species these species will be caught and released in pursuit of a full limit.