i may very well be wrong but i very much doubt that pressure change is that significant,
reason! wel the ocean is a great big pressure pot! 10m of salt water is the equilevent weight of our entire atmosphere! So to spell it out!
1 atmosphere ( ata) = 1020 hpa (approx)
10 meters of salt water ( msw) = 1 ata or 1020hpa
so 1 msw = 102hpa
A big pressure change would be say form a high of 1030 hpa to a low of 1000 hpa 30 hpa in total and
30 hpa = .3 msw ( approx)
So a fish only has to move up or down in the water coloum by .3m to duplicate the entire pressure change we get from at high to a low pressure system! Now i fish abit and know that a oncomming change in the weather brings on a bite, but this cannot solely be blammed on barometric pressure, there must be something else.
Ian
Ps. i've caught good fish in northerlies , but as the wind and the current gererally are going in the same direction when notherlies blow the fishing can be tricky. this does have an effect on catch rates!