No I think it is the norm, whenever you see them bringing up fish from the deep in submarines, they have to be in pressurized containers, otherwise they would be gonners (sp?)
Fish and decompression.
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Midnight Star
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That's a good point ... they die from an embolis, without being "sushied". Don't they have deep sea critters in the lab? I'm assuming they "decompressed" them, or are keeping them contained, and under pressure.
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Mike.
haha "sushied" I love it. Yea I think they keep them contained under pressure but I could be wrong I'm no scientist.
But I'm sure as you said some species have kept the ability to transverse great changes in depth without physical problems. But they would still have gas in the blood probably just have some intersting way of dispersing it? Dunno it would be interesting to research.
But I'm sure as you said some species have kept the ability to transverse great changes in depth without physical problems. But they would still have gas in the blood probably just have some intersting way of dispersing it? Dunno it would be interesting to research.
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DivetheRock
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Fishdiver, that's an excellent explanation. It's a wonder the fish simply don't blow apart, let alone their innards coming out of their mouths.
Midnight Star, perhaps different species' reactions to depth change varies greatly, or maybe it has something to do with healthy/weak and old/young fish and their reactions.
Midnight Star, perhaps different species' reactions to depth change varies greatly, or maybe it has something to do with healthy/weak and old/young fish and their reactions.
Well, since it is here, why don't we all take a few minutes to answer this question and maybe learn something else in the process.DivetheRock:
The first four paragraphs hit your fish question, reading the rest is well, up to you.DivetheRock:
http://www.bishopmuseum.org/research/treks/palautz97/deepstops.html
Enjoy!
Excellent source, ty Gene
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DivetheRock
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Yes, excellent information there, Gene. Thank you!
Dr Deco
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Hello Dive the Rock:
Gas Bladders
Fish have swim bladders that allow them to control their depth without a large expenditure of energy [from swimming]. In some fish, this bladder is connected to the gut, and the air can be expelled through the mouth. Other fish add or subtract oxygen to vary the amount of gas in the bladder. This is a slow process and a rapid change in pressure would cause a rupture of the bladder. This is what was seen on the fishing boat off Greenland.
Benthic Fish
Those creatures dwelling in the deep ocean under very high hydrostatic pressure must be placed into a pressure chamber before they are brought to the surface. This is a problem more related to pressure and the conformation (= shape) of molecules.
Decompression Sickness
This is a chance for everyone to see first hand the difference between hydrostatic pressure and partial pressure. Water breathing fish cannot get DCS. Why? Because they do not have any supersaturation. Seawater is in equilibrium with the air, at the surface and down to the sea bottom, as far as nitrogen is concerned. [Some oxygen is removed by metabolism.] The partial pressure of nitrogen at the surface is equivalent to that in the air, about 1 atm x 0.79.
The tissues of water-breathing fish are in equilibrium with this water. Independently of hydrostatic pressure, that is, where they are in the water column, from top to bottom, the partial pressure of nitrogen is 0.79 atm. Thus, rising to the surface will not cause any supersaturation and no DCS will occur.
Dr Deco :doctor:
Gas Bladders
Fish have swim bladders that allow them to control their depth without a large expenditure of energy [from swimming]. In some fish, this bladder is connected to the gut, and the air can be expelled through the mouth. Other fish add or subtract oxygen to vary the amount of gas in the bladder. This is a slow process and a rapid change in pressure would cause a rupture of the bladder. This is what was seen on the fishing boat off Greenland.
Benthic Fish
Those creatures dwelling in the deep ocean under very high hydrostatic pressure must be placed into a pressure chamber before they are brought to the surface. This is a problem more related to pressure and the conformation (= shape) of molecules.
Decompression Sickness
This is a chance for everyone to see first hand the difference between hydrostatic pressure and partial pressure. Water breathing fish cannot get DCS. Why? Because they do not have any supersaturation. Seawater is in equilibrium with the air, at the surface and down to the sea bottom, as far as nitrogen is concerned. [Some oxygen is removed by metabolism.] The partial pressure of nitrogen at the surface is equivalent to that in the air, about 1 atm x 0.79.
The tissues of water-breathing fish are in equilibrium with this water. Independently of hydrostatic pressure, that is, where they are in the water column, from top to bottom, the partial pressure of nitrogen is 0.79 atm. Thus, rising to the surface will not cause any supersaturation and no DCS will occur.
Dr Deco :doctor:
beautybelow
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Think we could have "I'm a water-breathing fish" put under logged dives? That's what I want to be when I grow up.
dumpsterDiver
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I think the Doc is wrong on this one. I'm still trying to explain exactly why but I come up with only questions... If a parcel of water is saturated with nitrogen at the surface and then the parcel is pushed down into the deep, then is the mass of nitrogen must be removed from the parcel? I think not. The only way for the partial pressure of nitrogen to be constant regardless of depth would be for nitrogen to be released as a parcel of water is transported downward. How?
Similarly, in an upwelling event for the partial pressure of nitrogen to remain fixed, the mass of nitrogen would need to increase proportionatly with decreasing depth (in order to keep the partial pressure fixed) What is the source for this extra nitrogen that the water must acquire as it is upwelled?
I think that nitrogen is considered inert to most biological activities and thus conservative or close to it except maybe for nitrogen fixing bacteria?
Based on this type of logic I think fish can get bent.
Similarly, in an upwelling event for the partial pressure of nitrogen to remain fixed, the mass of nitrogen would need to increase proportionatly with decreasing depth (in order to keep the partial pressure fixed) What is the source for this extra nitrogen that the water must acquire as it is upwelled?
I think that nitrogen is considered inert to most biological activities and thus conservative or close to it except maybe for nitrogen fixing bacteria?
Based on this type of logic I think fish can get bent.
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