Another idea, if you want to do the leg work, is to talk to the person who runs the fish counter at your supermarket. In fact, talk to several supermarkets and fish markets, if you have them. During various fish seasons, they will fillet the big fish coming in, and sometimes throw away fish heads and fish frames, including fins and tails. I take a big bucket with my name and phone number written on it. They fill up my bucket with whatever I want that they're tossing, and give me a call when it's filled. I pick it up and walk out with lots of fresh fish for free. Occasionally some markets want .99/pound esp. at the end of a fish season. Whatever...it's still cheap/free and more often it's wild fish too. Anyway, I can make meals for my family, and great protein meals for my chickens from this. Pressure cook up ALL the fish scraps for about 35 minutes, and all the bones, fins, head cartilege, etc. become soft and mashable. When it's cooled the liquid forms a solid gel. I pack into quart containers and freeze for the chickens. It's excellent. And absolutely NOthing hits the garbage can or compost. Nothing. The chickens eat all of it. And whenever family members go fishing, I request all the fish frames, skins, and heads too. My pressure cooker gets a workout during fishing season.