Bringing them up from deep water fast can kill them, and yes pressure is involved, you will get a good answer soon. My 2cts.
I was wondering if the biologists had any data or even just an opinion as to why on one day crappie caught 30-35' deep are unable to get back down without some real effort by the fisherman. Then on another day you can just flip them back in and away they go. Is there a chance that the barometric pressure might be the cause? I had this occur just this week.
Bringing them up from deep water fast can kill them, and yes pressure is involved, you will get a good answer soon. My 2cts.
The speed in which you bring them up is the key. They get the bends just like divers who surface too quickly after a deep dive. In fish the swim bladder and stomach can become filled with gasses if they are brought to the surface too quickly. Slowing your retrieve can help alleviate this a lot and letting the fish fight hard for a while before bringing them up the last 10 feet can help them naturally expel the stomach gasses. High atmospheric pressure can reduce this as the surface pressure of the lake will be higher as well leading to less of a pressure difference at the depth caught. Low pressure can increase the effect on them as well, but the biggest factor is the speed in which they are brought to the surface.
kazualobzerver LIKED above postHookin'&Cookin' thanked you for this post
Good info, thank you.