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 ...

While tuna is a rich source of protein and omega-3 fatty acids, questions about its safety—especially for pregnant women, children, and frequent consumers—have sparked ongoing debates.

KAWASAKI, Japan (AP) — 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 ...