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Healthy Ecosystem: A healthy ecosystem is characterized by optimal biodiversity, populations at carrying capacity, an age distribution as close to normal as possible, natural predator-prey balance, robustness to change, recovery of crashed populations, and minimal negative anthropogenic changes in all of these criteria.
Fish: Many organisms are taken from the oceans, so for convenience we adopted Magnuson-Stevens Act definition (found in Section 3) as including finfish, crustaceans, mollusks, and marine animals but excluding plant life, mammals, and birds.