North Dakota Game and Fish Department fisheries biologists are encouraging ice anglers to keep fish caught from deep waters. Catch-and-release fishing, no matter the time of year, is discouraged for fish caught in 30 feet or more of water, because fish reeled in from those depths have a greater chance of dying if released.

Fish caught in deep water won’t likely survive because of the extreme change in water pressure, which causes the swim bladder to expand. Fish can no longer control their balance in the water column when this happens. Other internal injuries, such as rupturing of organs and bleeding, are also likely for fish caught from deep waters.