The reason they do not allow them to sell the halibut is that it is likely much more valuable than there target species.

example would be a rock fish trip I did in the gulf.Our "target species was POP(Pacific Ocean Perch).The gov new it was impossible to cleanly target P.O.P..So they aloud us to process the by-catch.I think 17% could be Black cod.Black Cod was worth FAR more than P.O.P.We made sure that we had our full allowed % of Black cod.This meant grading our catch in the sorting room i.e throwing fish overboard.we threw tons of P.O.P and pacific mackeral overboard to get the 17% of black cod.Ultimately we were targeting Black cod.They are afraid this would happen with halibut also.This by the way was done on a boat with a norwegian first mate.First mate my as.

They have changed the quotas to facilitate a lot less waste forcing them to proccess much more of what they catch versus solely targeting one species.

I think that they should be forced to process all they catch but not necesarily being able to sell the fish at market value.Problem is that it would drive the price of "Halibut" down.The halibut lobby would fight this tooth and nail.edit:If all they caught came out of there quota they would be more likely to fish in ways that would mean less by-catch.