When we catch one we would wack it between the eyes a couple of times, then when it was no longer moving, take a sharp knife and buck both wings off, fast, then get them on ice. An old dragger captain told me how to care for them as before we would just cut the line and let them go. They are not bad to eat, but a bit of work skinning them and cutting up the meat. And just like halibut, the little ones are better eating.
SS