It is not my intent to get into applied physics too deeply. Objects under water are compressed equally on all surfaces. If you blow up a ballon and submerge it about 35 feet, the ballon will shrink about 50% of it's diameter as the internal air is compressed by the pressure of close to 1 atmosphere or approximately 15 pounds per square inch. The ballon submerged 17 feet would have about 7 psi compressing it and will be about 75% of it's diameter. At 8 feet down, about 3 psi, the ballon is about 90% of it diameter. Bass feel the same pressure compressing thier airblader. Bass living at 35 foot depth, with neutral buoyancy in the airbladder at that depth, will experience 1 atmospher, 15 psi, pressure change, if it swims up to the surface. The basses airbladder expands and compresses exactly like the ballon. 1 atmosphere or 35 foot depth raise is about the limit a bass can tolerate without it's airbladder doubling in size.
How does 100 millibars (1 bar is about 1 atmosphere) or about 1.5 psi or 2 feet of water pressure, adversely affect a bass? 100 millibars is equal to a big low pressure depression the size of a hurricane.
I agree they can feel it, don't agree that barometric pressure alone has much impact on bass. The changing light with increasing cloud cover, increased flying insects associated with a low pressure system does increase bass activity. The passing cold front and increasing high pressure with bright sun and high winds, also can adversly affect bass living in water less than 5 feet deep. All the bass needs to do to reestablish it's airbladder nuetral bouyancy is; make a 1 1/2 foot depth change to compensate for 100 millibars of atmospheric pressure change.
The affects of cold water, more than 10 degrees can be fatal to a bass. If a big storm lowers the surface temperature by 10 degrees quickly, the water near the original thermocline will be about equal to its original tmeperature, so the deeper bass are not affect by fast surface water temperature changes.
Target the deeper bass and barometric changes have little affect.
WRB