I know this is a practice saltwater fisherman have used for bottom fishing for years - fish like gruoper and snapper that are not big enough to keep many times have to have their air bladder popped - like you I don't know what happens when they get out of sight but they will swim off - they appear to have a chance this way - but if you leave them floating on the top they are goners for sure - I guess they will be part of the food chain though for some other fish
with my mind on crappie and crappie on my mind -
and if ya'll see Goober later tellem I said duh huh - he'll know what ya mean!!!!!!!!