MeHg from fish consumption is the most common source of exposure to the general population from the environment. Elemental Mercury is bio-transformed to methylmercury in the Environment, and it is bio-concentrated in aquatic systems. Catfish are pisciverous fish, meaning they eat other fish and can be expected to bio-accumulate appreciable amounts of methylmercury. Although our analytic tools were only specific for the determination of total mercury, the literature supports the assumption that mercury found in flesh will be in its organic form.