While not seen in the US in many countries process all kinds of fish for human consumption. The use of large amounts of fish (mostly from the sea) for conversion to fish meal for feeding fish is in some places met with the accusation that you are using the fish for recreation (U S production) while third world peoples are starving. Much like the argument that using corn for fuel results in starving people.

I am not starting a political discussion so please don't go there. Just pointing out that some take that position and it can/may effect our access to enough fish meal.