Post by mwardncsu on Jun 26, 2014 22:02:26 GMT -5
In some of our recent discussion regarding summer time C&R, the issues of catching striper in depths and then trying to release have been mentioned A fellow striper fisherman from GA that I consider a and one of the better river striper fisherman authored the below last year based on his personal research into the issues. He also had the goal of conveying these issues in an easy to understand manner, educating fellow striper fishermen and women in the process. He was kind enough to allow this to be re-used here in order to help spread education of this issue with his fellow striper-breathern on SML and elsewhere. The information presented is based on his personal research and interpretation of that information - and there may be areas in which there is disagreement or differing viewpoints, though his interpretation generally holds consistent with others views on this topic.
This can often be a contentious subject, but one that needs to be understood so that you can make decisions on your fishing practices from an educated perspective. I welcome discussion on the topic - discussion is where we all learn from the collective group, but as always, and especially with the topic of summer fishing - let's keep it respectful.
One initial question that might come up from below is "what is deep water"? For purposes of this discussion - let's assume greater than 40', maybe >35' or so ....... Mike
There are 3 main issues that often lead to the death of a fish when pulled up from deep water in the heat of the summer:
1) Swim Bladder Expansion - The swim bladder of most fish (including Stripers) is filled with OXYGEN, not air but oxygen. The way it gets there is the hemoglobin in the fishes blood releases O2 into the swim bladder. The deeper the fish goes the more Oxygen it has to put in the swim bladder to maintain neutral buoyancy due to the fact that the pressure increases (fish swims deeper). When a fish is pulled up from the deep the Oxygen expands as the pressure decreases (fish gets closer to surface). Often the swim bladder expands so much, and so rapidly, that it rips loose the organs inside the fish and can even cause the stomach to be pushed out the throat into the fishes mouth. Some fishermen use the butt of a fishing rod to force the stomach back down the throat. Unfortunately once the stomach is dislodged to a point it comes out the mouth then many of the glands that help the stomach digest, blood vessels, etc. are also dislodged or damaged and the chances that the stomach will work properly again are slim. Imagine if something inside your body expanded so much that your stomach came out your mouth and your buddy just crammed it back down your throat. Would you be OK, and would your stomach still work properly???
2) Lack Of Oxygen In The Blood/Body (Lactic Acid build-up) - The way that a fish gets Oxygen to survive, and releases CO2, is the similar to humans in that they have red blood just like us (though they use gills, not lungs). The blood contains hemoglobin which carries the Oxygen from the gills to all the cells in the fishes body and then carries the Carbon Dioxide to the gills to be released. When a fish is hooked and it fights really hard, the Oxygen in its blood is rapidly used up and needs to be replenished. Also during a hard fight the fishes blood also becomes more acidic, because the cells in the fish are burning glucose faster than it can absorb new oxygen, so instead of producing lots of energy with CO2 and Water as waste, as the fight goes on for a long time the fishes muscle and other cells instead begin to burn glucose but with not enough Oxygen they produces only a little bit of energy and Lactic Acid as waste. The more Acidic/lower PH the blood becomes the less Oxygen the hemoglobin in the blood can carry, therefore to live the fish needs the water it is in to have even more Oxygen than normally required (because it is using more and it is not getting it as efficiently). Unfortunately for fish caught in the summer, the shallower they get the warmer the water gets, and the warmer the water gets the less dissolved Oxygen it can hold. Bottom line is that when you catch a Striped Bass in the summer and much of the fight occurs in water that has low oxygen levels the fishes cells are literally starving for Oxygen before you even lift it out of the water. The longer it goes until it is back into high dissolved O2 water, the more Lactic acid is produced, and the more damage is done to the fishes organs, muscles, and other cells which may or may not be able to recover.
3) Thermal Stress - It has been proven on MANY studies that Stripers are more likely to die the warmer the water is, especially once it gets over 70 degrees. Length of the fight (shorter fight=less time in warm water=better chance fish lives) and the condition of the fish before hooked (a fish already struggling to survive due to warm water and/or low Oxygen levels, is WAYYY more likely to die than a healthy fish) are important factors on whether the fish can take being caught in warm water. Also the size of the fish is extremely important on how it will do when caught in warm water. In my opinion small Stripers <5 lbs often are fine in water up to low 80 degrees, medium Stripers 5 lbs - 20 lbs can take water temps up to 78 degrees, and large Stripers 20 lbs+ will suffer and often die in waters warmer than 72 degrees. These numbers are averages based on my experiences catching Stripers in different water temperatures and articles and studies I have read about striped bass mortality due to thermal stress. Also extreme temperature changes from cold to hot can cause fish to die very quickly as most of us "bait netters" know. A shad can easily tolerate water 90+ degrees, but not if you take it out of a 65 degree bait tank and drop it in 90 degree water and it will die very quickly from the shock of the temperature change. Therefore I believe it it reasonable to assume that if a Striped bass is pulled out of 50-60 degree deep cold water up to 80+ degree water during a fight, it is likely to go into thermal shock and likely die.
One other thing worth thinking about is "fizzing". The swim bladder must be a SEALED container to be able to hold in the Oxygen and not allow in water even deep where the pressure is extreme (can easily blow your eardrums out just swimming down to 40 feet). Punching a hole in a fishes swim bladder will make it go to the bottom for sure so if you just want it out of sight, it will accomplish that. The fish will have to keep trying to swim up or it will keep sinking to the bottom, because it can't get any floatation because it has a hole in the organ that allows it to be buoyant.!.!.! Punching a hole in the swim bladder is a death sentence to any fish in my opinion.
"Torpedoing" the fish down might get them down to 8 or 10 feet and if the fish is in decent shape might help it get on track to keep swimming back to the depth it was at. This is assuming though that the fish is in good shape and still wiggling and kicking hard when you torpedo it. If the fish is not moving then torpedoing it down might make it disappear temporarily but it will be dead soon and back on top (unless you fizzed it) very soon IF you caught it at 60+ feet deep.
There are probably other factors as well but these are 3 biggies that Striper fishermen that practice Catch & Release should be aware of when fishing for Stripers deep in the lakes during the summer. Very few Striper fishermen fish deep in the cooler months, because normally the Stripers are not down there as most the baitfish are usually shallower and temp/oxygen is not an issue. If they were they would still have to deal with # 1 above, but #2 and #3 would not be an issue. I think that it is the combination of 2, or all 3, of the problems listed above that makes the chance of survival almost non-existant when you hook one in the summer at 60+ feet. I have done a reasonable amount of research and testing myself on this and I believe that Catch & Release not a viable option on most lakes (with mid 80's or higher surface temps) in July-August IF you are catching fish down at 60+ feet deep. If the fish is hanging out near the Thermocline which is often in the 30 foot deep range in June/July I think you do away with #1 above, as well as help a little with #3 as far as extreme temp change thermal stress. The fish still might die from #2, but its chances are significantly better to survive...
This can often be a contentious subject, but one that needs to be understood so that you can make decisions on your fishing practices from an educated perspective. I welcome discussion on the topic - discussion is where we all learn from the collective group, but as always, and especially with the topic of summer fishing - let's keep it respectful.
One initial question that might come up from below is "what is deep water"? For purposes of this discussion - let's assume greater than 40', maybe >35' or so ....... Mike
There are 3 main issues that often lead to the death of a fish when pulled up from deep water in the heat of the summer:
1) Swim Bladder Expansion - The swim bladder of most fish (including Stripers) is filled with OXYGEN, not air but oxygen. The way it gets there is the hemoglobin in the fishes blood releases O2 into the swim bladder. The deeper the fish goes the more Oxygen it has to put in the swim bladder to maintain neutral buoyancy due to the fact that the pressure increases (fish swims deeper). When a fish is pulled up from the deep the Oxygen expands as the pressure decreases (fish gets closer to surface). Often the swim bladder expands so much, and so rapidly, that it rips loose the organs inside the fish and can even cause the stomach to be pushed out the throat into the fishes mouth. Some fishermen use the butt of a fishing rod to force the stomach back down the throat. Unfortunately once the stomach is dislodged to a point it comes out the mouth then many of the glands that help the stomach digest, blood vessels, etc. are also dislodged or damaged and the chances that the stomach will work properly again are slim. Imagine if something inside your body expanded so much that your stomach came out your mouth and your buddy just crammed it back down your throat. Would you be OK, and would your stomach still work properly???
2) Lack Of Oxygen In The Blood/Body (Lactic Acid build-up) - The way that a fish gets Oxygen to survive, and releases CO2, is the similar to humans in that they have red blood just like us (though they use gills, not lungs). The blood contains hemoglobin which carries the Oxygen from the gills to all the cells in the fishes body and then carries the Carbon Dioxide to the gills to be released. When a fish is hooked and it fights really hard, the Oxygen in its blood is rapidly used up and needs to be replenished. Also during a hard fight the fishes blood also becomes more acidic, because the cells in the fish are burning glucose faster than it can absorb new oxygen, so instead of producing lots of energy with CO2 and Water as waste, as the fight goes on for a long time the fishes muscle and other cells instead begin to burn glucose but with not enough Oxygen they produces only a little bit of energy and Lactic Acid as waste. The more Acidic/lower PH the blood becomes the less Oxygen the hemoglobin in the blood can carry, therefore to live the fish needs the water it is in to have even more Oxygen than normally required (because it is using more and it is not getting it as efficiently). Unfortunately for fish caught in the summer, the shallower they get the warmer the water gets, and the warmer the water gets the less dissolved Oxygen it can hold. Bottom line is that when you catch a Striped Bass in the summer and much of the fight occurs in water that has low oxygen levels the fishes cells are literally starving for Oxygen before you even lift it out of the water. The longer it goes until it is back into high dissolved O2 water, the more Lactic acid is produced, and the more damage is done to the fishes organs, muscles, and other cells which may or may not be able to recover.
3) Thermal Stress - It has been proven on MANY studies that Stripers are more likely to die the warmer the water is, especially once it gets over 70 degrees. Length of the fight (shorter fight=less time in warm water=better chance fish lives) and the condition of the fish before hooked (a fish already struggling to survive due to warm water and/or low Oxygen levels, is WAYYY more likely to die than a healthy fish) are important factors on whether the fish can take being caught in warm water. Also the size of the fish is extremely important on how it will do when caught in warm water. In my opinion small Stripers <5 lbs often are fine in water up to low 80 degrees, medium Stripers 5 lbs - 20 lbs can take water temps up to 78 degrees, and large Stripers 20 lbs+ will suffer and often die in waters warmer than 72 degrees. These numbers are averages based on my experiences catching Stripers in different water temperatures and articles and studies I have read about striped bass mortality due to thermal stress. Also extreme temperature changes from cold to hot can cause fish to die very quickly as most of us "bait netters" know. A shad can easily tolerate water 90+ degrees, but not if you take it out of a 65 degree bait tank and drop it in 90 degree water and it will die very quickly from the shock of the temperature change. Therefore I believe it it reasonable to assume that if a Striped bass is pulled out of 50-60 degree deep cold water up to 80+ degree water during a fight, it is likely to go into thermal shock and likely die.
One other thing worth thinking about is "fizzing". The swim bladder must be a SEALED container to be able to hold in the Oxygen and not allow in water even deep where the pressure is extreme (can easily blow your eardrums out just swimming down to 40 feet). Punching a hole in a fishes swim bladder will make it go to the bottom for sure so if you just want it out of sight, it will accomplish that. The fish will have to keep trying to swim up or it will keep sinking to the bottom, because it can't get any floatation because it has a hole in the organ that allows it to be buoyant.!.!.! Punching a hole in the swim bladder is a death sentence to any fish in my opinion.
"Torpedoing" the fish down might get them down to 8 or 10 feet and if the fish is in decent shape might help it get on track to keep swimming back to the depth it was at. This is assuming though that the fish is in good shape and still wiggling and kicking hard when you torpedo it. If the fish is not moving then torpedoing it down might make it disappear temporarily but it will be dead soon and back on top (unless you fizzed it) very soon IF you caught it at 60+ feet deep.
There are probably other factors as well but these are 3 biggies that Striper fishermen that practice Catch & Release should be aware of when fishing for Stripers deep in the lakes during the summer. Very few Striper fishermen fish deep in the cooler months, because normally the Stripers are not down there as most the baitfish are usually shallower and temp/oxygen is not an issue. If they were they would still have to deal with # 1 above, but #2 and #3 would not be an issue. I think that it is the combination of 2, or all 3, of the problems listed above that makes the chance of survival almost non-existant when you hook one in the summer at 60+ feet. I have done a reasonable amount of research and testing myself on this and I believe that Catch & Release not a viable option on most lakes (with mid 80's or higher surface temps) in July-August IF you are catching fish down at 60+ feet deep. If the fish is hanging out near the Thermocline which is often in the 30 foot deep range in June/July I think you do away with #1 above, as well as help a little with #3 as far as extreme temp change thermal stress. The fish still might die from #2, but its chances are significantly better to survive...
