Bill -
Need to remember the bass - both largemouth and smallmouth , hve a closed air bladder much like that found in rockfish. When they are subject to pressure changes - brought from depth; the bladder expanded and the fish can not vent the gases.

As a result the expanded bladder puts pressure on the fish's organs and the stretching of the tissues can cause hemorphaging both of which cause mortalities.

This time of the year smallmouth tend to still be in their deep water winter haunts and are vulunerable to problems when brought from the depth. With the depth changes typical this time of year it seems that initially the fish's body/tissues are strong enough to hlod the bladder in place but after a few minutes (less than 5) the tissue weaken, bladder expands and the fish has problems.

While it is rare for the bladder to expand to the point that it casues the fish's bladder to stick out its mouth as with rockfish it is pretty common to see fish brought from say 40 feet and placed in a live well to be found swimming upside down after a few minutes - see the same thing with perch in the fall when brought from some depth. Clearly the fish are being stressed; of course that isn't a problem if the fish are being kept for the table but may not be so good if the idea is to release the fish alive for another day.

While the overall mortality from the deep water tournaments are not much of an issue to the bass population as a whole it probably does reduce the overall age of the population. Certainly those anglers that do fish deep should be aware that they are probably killing some fish and likley have as much impact as the anglers that kill some fish for the table.

I for one have to question the wisdom of having these early season tournaments when the best chance for a winning weight comes from fishing deep. This is especially true if the idea is to have minimal impacts on the fish. In fact I will not fish deep water for bass and limit my fishing to less than 30 feet - yes that means I will not be a top rod but I feel I can comfortably release the fish I catch and know that a large portion will be available for another day for another angler or myself.

Tight lines
Curt