Rockfish caught by anglers and brought to the surface suffer from barotrauma - gas expansion injuries - that can be fatal unless fish are properly descended back to depth.
Barotrauma is a painful and potentially fatal condition for rockfish and other deep-water species. The gas expansion caused by rapid ascent can rupture internal organs and prevent fish from swimming back down. When fish are brought to the surface for catch-and-release fishing, using descender devices is the most welfare-positive approach to maximise survival. Regulatory requirements for descender device use are increasingly common in rockfish fisheries.