Panfish, such as bluegill and crappie, and trout eat insects and other aquatic life that are less likely to contain high levels of contaminants. Top predators like bass, walleye, and catfish may have higher levels of contaminants. If you eat these species, eat the smaller fish to minimize your exposure. Clean and cook fish properly. How you clean and cook fish can reduce the level of contaminants by as much as half in some fish.
Some chemicals concentrate in the fatty tissues and internal organs of fish.
Filleting the fish, removing the skin and internal organs, and trimming the fat along the back, side, and belly of the fish helps reduce the contaminants in fish. While cooking does not destroy contaminants, heat from cooking melts some of the fat in fish and allows some of the contaminated fat to drain away. Broil, grill, or bake the trimmed, skinned fish on a rack so that the fat drips away. Deep-fat frying removes some of the contaminants, but you should discard the oil after you cook the fish. Pan frying does not remove much of the contaminants.