Fishing Deep Water and Ethics

[reinhard1]

i just want to say that i for one look forward to every single one of your posts. we talked last fall about a get together up in duluth with northlander also. hope that can happen. dont let one poster rile you up. there are plenty here that like your posts and experience. expecialy those island lake posts, like the shore fishing last fall. walleye's next to the landing dock. hope you have a good day. good luck.

[Big Tom]

Fishinfey8, a lot of truth to what you posted, BUT universal value judgements about who or what is a "Good" vs. "Bad" something will usually get you some challenging responses. Heck, there are a few here who count on that maxim.

[jwmiller33]

lakers have a way to adjust comming up

Yup you are right. Trout and Salmon species are the only species (that I am aware of) who have the ability to adjust for quicker than normal changes in pressure (unlike other species like walleye and panfish) which is why you can fish for them in deep water and have successful releases. It's too bad other species weren't able to adapt with this as we wouldn't even be having this conversation.

Does anybody know what it is called that allows trout and salmon the ability to adjust for changes in pressure without dying? I have been trying to look it up online all morning and haven't been able to find out specifically why that is.

[jwmiller33]

I found this info from the New York DNR:

Quote:

A moderate steady retrieve will give the fish time to adjust to changes in water pressure. Trout and salmon caught in many cold water lakes are caught in very deep water. Bringing them to the surface is particularly stressful because the fish experiences a substantial reduction in water pressure. At 100 feet deep the pressure per inch is four times greater than at the surface. In this situation it is important not to "horse in" the fish but to bring it to the surface slowly but steadily.

Fish brought up from deep water may need "burping." Burping is a method of expelling excess air from the fish's swim bladder. The drop in pressure causes the swim bladder to expand, increasing the fish's buoyancy and causing it to float belly up. Left in this condition, many fish die as a result of the surface water's warm temperatures or attacks by predators. But in trout and salmon, the swim bladder is connected to the esophagus, making it possible to squeeze excess air out. To do so, hold the fish gently on its side and gently, but firmly, squeeze the belly from the vent toward the head. You will be able to hear the burp as air is expelled from the bladder. Do not squeeze the head and gill area, as that could damage vital organs.

Stimulate the fish to dive deeply. Once burped, the fish should be able to dive down to the deep cold water. But it may require further assistance. Two methods have proved useful in stimulating fish to dive. One is to vigorously thrust the fish, head first, into the water. The slap of the water, and the plunge downward usually stimulates the fish to swim down. Another technique is the "release when recovered" method. Hold the fish gently at the middle of its body with its head pointed downward at a 45 degree angle. In that position a gentle side-to-side motion (or slow speed of the boat if trolling) can be used to move water into the mouth and over the gills. As the fish recovers, it will begin to kick, and slide out of your hand. When its tail passes through your hand, give the tail a quick squeeze. This seems to stimulate the fish's swimming action, causing to dive with more vigor. Remember, the idea is not to catch the tail, but to compress it as it slides through your hand.

[jwmiller33]

Here is some more interesting info I found on a study done on this particular matter by rockey mountain anglers:

Quote:

Freshwater fish have an internal organ known as the swim bladder which allows them to

regulate the amount of gas in their bodies and, hence, their buoyancy. Neutral buoyancy

enables a fish to remain motionless in midwater and reduces energy requirements of

swimming. At any time, a fish is in buoyancy equilibrium at one depth only.

There are two basic types of swim bladders in freshwater fish. Physostomous fish possess

a pneumatic duct which connects the swim bladder to the alimentary tract. These fish,

which include carp, esocids, trout and salmon, can expel gas and make buoyancy

adjustments more quickly than physoclistous fish. Physoclistous fish, which include bass,

walleye, perch and most panfish, have closed swim bladders with no connecting duct

between their swim bladder and alimentary tract. Deflation is accomplished by diffusion of

gas via a network of capillaries. As a result, these species are unable to release air

quickly.

The Problem of Rapid Depressurization

Rapid removal of fish from deep water to the surface by traditional angling techniques does

not allow an ample time for depressurization.

Effects of depressurization can include:

• Over-inflation of the swim bladder,

• Inability to submerge when released - exposure to predation and

solar radiation,

• Abnormal or erratic swimming behaviour,

• Protruding eyes,

• Gas embolisms (blood vessels, gills, skin and brain),

• Protrusion of internal organs through the mouth,

• Internal and/or external hemorrhaging,

• Cloacal protrusions,

• Death.

Although the most obvious sign of depressurization is an over-inflated swim bladder,

damage to other critical tissues, including the brain and heart, due to gas bubbles in the

blood is often a cause of death.In Lesser Slave Lake, Alberta, walleye angled from waters between 7.6 and 10.1 m in

depth were found to have significantly higher serum aspartate aminotransferase,potassium, and lactate concentrations which indicated increased hypoxia and muscle injury

in comparison to the shallow-caught fish (R. L. & L. Environmental Services Ltd. 1995).

Based on a relatively small number of studies which have been conducted to date,

depressurization of angled fish can be a significant source of mortality (Table 1). Up to 45%

of fish caught at depths exceeding 10 m do not survive release (Anonymous 1991b).

fyi, 1M = 3.2 ft

[LoonASea]

You know the problem with posting on forums (if you want to call it a problem) is text can be interpreted out of context of the person posting ,,,,you cant see the facial expression, tone of voice or even the mood of the person,,,not trying to defend any ones opinion ,,I just want to bring to light that you can not judge a posters intent with text alone,,,I dont post as much as most people on this forum but will when I have something positive to post ,,,call me old school but if I dont have something positive to say I say nothing

Sorry for hijacking the thread

LAS

[leech~~]

You know the problem with posting on forums (if you want to call it a problem) is text can be interpreted out of context of the person posting ,,,,you cant see the facial expression, tone of voice or even the mood of the person,,,not trying to defend any ones opinion ,,I just want to bring to light that you can not judge a posters intent with text alone,,,I dont post as much as most people on this forum but will when I have something positive to post ,,,call me old school but if I dont have something positive to say I say nothing

Sorry for hijacking the thread

LAS

Huum, my Mom use to tell me that too! Good old Mom! I think you and her may have been right.

[Nick Kuhn]

Good read there. Looks like only crappie and rainbow trout are the ones that are more likely than not to die. Looks like most of the walleye will survive, especially if you are taking special care of them.

[gurkster]

The only time this is an issue for me is on LOW ice-fishing for walleye/sauger. Pulling in smaller fish from 30+ feet of water, they sometimes come up with their air-sack in their mouth. If this happens to us we keep the fish regardless of size and it goes towards our limit count. If it persists we upsize our presentation, and try and reel them in slower if they seem small. Other fish and open water I am almost never in those depths on the lakes I fish. So to answer your question I rarely target fish at that depth, and if I do those fish are kept for the table.

[Swimmer]

I was marking huge pods of baitfish close to the bottom in 70 to 90 feet of water a couple Falls ago. We were also marking GIANT arches that were likely the Muskies we were looking for. We chose not to target those fish for obvious reasons. Getting skunked while Musky fishing is not a novel thing; and killing a 50" fish for a couple of photos would have been tragic.