So one reason could be that when people are asked to also complete the iREC survey, they will be prompted to look at their paper license and enter the size of each retained fish possibly? They do this for halibut, and have been now for 2 seasons. We can drill down into the iREC data to build out a model that captures how many within the total iREC sample fall into each cm length and bucket that data to help us better model where our halibut TAC is being used up. What we learned is the recreational catch closely mirrors the IPHC and commercial catch and that our fishery is driven by the smaller fish that now make up the vast majority of the available to catch biomass. So its the smaller size ranges that drive the recreational catch - so when we moved up the daily possession of 2 small unders, that was responsible for using up so much of our TAC very quickly, not the bigger fish as they are not readily available to catch.
So for Chinook, this data may be very useful in understanding the long term size at age trends in the Chinook catch and population. I would also add that there are many other interest groups that accuse the recreational fishery of high grading Chinook - this also might be helpful data to prove or dis-prove those assertions!