KAWASAKI, Japan — Seafood lovers know the fatty marbling is what makes tuna sashimi and sushi so tasty, so for the industry, it's the fish's level of fattiness that's used to judge its quality ...

KAWASAKI, Japan -- Seafood lovers know the fatty marbling is what makes tuna sashimi and sushi so tasty, so for the industry, it's the fish's level of fattiness that's used to judge its quality ...