Prairie State Outdoors has an article about a novel fish processing plant in downstate Havana, IL which turns the vast numbers of invasive Asian carp in the Illinois River into fertilizer. The plant uses a steam process to separate the fish into valuable Omega-3 fish oil and nutrient rich fish meal.
Though the carp are said to be delicious, only a few processing plants such as Shafer Fisheries have found a market for selling the fish as meat.
As invasive species, bighead and silver carp have no enemies in this habitat, except humans. So one way to slow their destructive invasion and spread through the Illinois River watershed is to simply get out there and catch them, whether for food or fertilizer.