Metal residues in farm-raised channel catfish, rainbow trout, and red swamp crayfish from the southern US

Farm-raised channel catfish (Ictalurus punctatus), rainbow trout (Oncorhync hus mykiss), and red swamp crayfish (Procambarus clarkii) were collected fr om production and processing sites across the southern U.S. and analyzed fo r barium, cadmium, copper, chromium, silver, lead, arsenic, selenium, and m ercury. Average metal residues were much lower than recommended safety limi ts. Residues of barium, copper, and mercury were slightly higher in crayfis h than catfish or trout. Selenium was higher in crayfish and trout than cat fish, and lead was higher in catfish and trout than crayfish. Residues of m ercury in all samples were much lower than the FDA's Action Limit (1 ppm) f or mercury in the edible tissue of fish.