I bet that study was funded by a group that wants you to buy "safe" farm raised fish. No point in catching those nasty wild fish cause they are full of cancer chemicals.
In the north, Minnesota, Wiscosin, Michigan, etc... a lot of people fish but they dont eat the fish cause the gubberment or somebody has convinced them that the fish are contaminated with mercury and other chemicals. I always wondered how those fish are even alive if they are contaminated that bad.