what kind of fish is yellowfin
1 Bigeye and yellowfin, also known as ahi, are common in sushi. 2  Both types, along with bluefin, are high in mercury and should be eaten infrequently, if at all. 3  Most tuna are caught by purse seines or longlines, which have moderate-to-high bycatch of seabirds, sea turtles and marine mammals.