That would really depend on the species. Let me go back to the example for rockfish that I mentioned. Rockfish, for example, are fish that have a closed swim bladder. When they get pulled from the depth, where they live, say, 40, 60, even 30 metres, their swim bladder expands and they cannot go down again. For the example of rockfish, there's actually about a 90% to 95% mortality even if their release is attempted. There are studies on various species that show what the mortality rate is, and in some cases that's not such a problem and for other species it is.
On November 30th, 2017. See this statement in context.