Seafood processing plants are required to have a plan for what they are going to do with their waste and wastewater. There are a few options, namely, grind and discharge (probably the most common), 100% utilization (no waste), and land application, to name a few.
The rules in the State of Alaska on discharge of seafood wastes are very specific. The maximum particle size is 1/2″, so a grinder is required to break the parts down to the requisite size. JWC Environmental manufactures the Muffin Monster series of grinders, that can grind through just about anything.