I saw a video on bowfishing the last time I was up at Cabelas. They had it playing on a small tv in the archery section of the store. Showed a whole family out shooting carp!
I think if someone became enterprenurial enough in a state that allows unlimited harvesting of carp; one could quick freeze and ship them overseas for food consumption.
Making compost out of fish bones and guts is a no brainer. Just chuck the remains into a blender and give it a whirl with some water. Pour that onto your compost pile and add some soil above it to keep the odor down. It WILL attract raccoons, skunks, opposums, and other vermin if not 'soiled down' and mixed in to your compost pile.