Something to think about from IPHC 2014 bluebook
Estimates of recreational removals have historically not included any estimates of mortality associated with captured and subsequently discarded halibut (Williams 2014). During 2013, estimates of recreational discards were produced for the fishery in Areas 2C and 3A (S. Meyer, ADFG; letter to the IPHC, 13 November, 2013). That analysis indicated that additional mortality on the order of 2-3% of the retained catch might be reasonable given the regulations currently in place. With no direct estimates for other regulatory areas, and little comparability among regulations currently and historically in place, it is difficult to hypothesize what magnitude of total coast wide recreational wastage might be plausible. Therefore, a simple sensitivity of adding 5% to all recreational removals in all years was conducted. This revealed that for the coast wide stock assessment there was no appreciable change in the estimated spawning biomass time-series (Fig. 13). Further evaluation into proxy estimates for each regulatory area, as well as sensitivity of harvest policy application to recreational wastage will be explored in future analyses.
And this....
Discards. Currently, very little is known about the size/age of discards for some directed fisheries. In addition, the increasing use of size restrictions in sport fishery management to more fully achieve harvest goals increases discards, but data collection programs are lacking, and implications to the IPHC harvest policy are unclear