Use a rather large bell jar and use it to lift a large body of water. The partial vacuum causes the swim bladders to enlarge, and the fish float to the top.
-- Ling, Apr 01 2008

Not sure that would work. Fish can easily swim thirty feet up and down without losing control of their buoyancy.
-- ldischler, Apr 01 2008


Exactly - wouldn't work. Also, vacuums in the more conventional sense of large suction tubes are already widly used in the fishing industry.

Incidentally, most fish catch the prey not by biting it, but by a really hard suck.
-- DrCurry, Apr 01 2008


//thirty feet//

Scale this thing up. Lift the water from the Pacific Ocean to wading level, and prepare to fry up some deliciously popped deep sea creatures. I'm gonna need a bigger reel.

This would require lifting the weight of the water, leaving less hydraulic pressure in the remaining pool (It's a pressure difference, not really a "vacuum"). The fish inside the bell jar may be fine. But grab a fish quickly -- the oceans are connected.
-- Amos Kito, Apr 01 2008


Of course fish can keep their bouyancy from atmospheric to 1 bar (probably much more). But this idea uses less than atmospheric, which I am sure most fish have never experienced.
-- Ling, Apr 02 2008


//Scale this thing up. Lift the water from the Pacific Ocean to wading level//

You fail... at basic physics. You wouldn' be able to lift seawater any higher than (... bloody imperial units, might as well go back to the stone ages) ~32 feet, higher density of salt water notwithstanding. Nice round number of 10m is easier, even though it's 9.81.

[Ling] got it right by saying 30 feet.
-- Custardguts, Dec 05 2008



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