Here's an article from the ND GFP, hope it helps.
North Dakota Game & Fish Department Release:
Catch and release is a fishing practice that can help maintain fish populations. However, catch and release is not recommended for fish caught from depths of more than 30 feet, according to Randy Hiltner, fisheries biologist for the North Dakota Game and Fish Department, Devils Lake.
Several lakes and reservoirs in North Dakota offer anglers a chance at catching fish from depths of 30 feet or greater. "Anglers fishing Devils Lake commonly catch yellow perch in 40 to 45 feet," Hiltner said. "Likewise, many walleye and sauger caught in Lake Sakakawea during winter are from more than 30 feet. Unfortunately, often fish are considered too small and are then released.
"But at those depths, fish likely will not survive because of the extreme changes in pressure," Hiltner continued. "At the depth those fish are being caught there is one atmosphere or more of pressure change, and going from high pressure to lower pressure causes the swim bladder to expand, thus putting pressure on the internal organs and causing other bodily problems."
A few species, such as lake trout, can adjust to rapid pressure changes, Hiltner said, but most of North Dakota's native species, including walleye, sauger and yellow perch, are not adapted to compensate for rapid changes in pressure.
Reeling fish in slowly from deep water does little to alleviate pressure changes, Hiltner said, because it can take up to 30 minutes for a fish to adjust to the pressure. Also, letting gas out of the swim bladder (fizzing) by inserting a needle is not recommended, even though it does help fish return to the bottom of the lake. "Many fish will die within a few days because anglers may damage internal organs with the needle," he added. "In addition, winter is not a good time to experiment with fizzing because cold air temperatures can quickly freeze portions of the fish, especially its eyes."
Anglers should still continue to practice catch and release, Hiltner said, but in the right situation. "It is best to keep fish that are caught from deeper waters to minimize wasting the resource," Hiltner said. "If anglers are just fishing for recreation and do not want to keep fish, they should target fish in shallow water."