This study investigated patterns of the accumulation of two metal pollutants - mercury and selenium - in various species of fish from varying waterbodies.  As an excessive amount of mercury in fish and shellfish consumed has the potential for adverse health effects, most state and federal water resource agencies measure the amount of mercury in edible fish fillet samples.  This study evaluated levels of mercury and selenium not only in fillet samples, but in fish ear bones (these are called otoliths).  Ear bones accumulate environmental pollutants over the course of a fish's lifetime.  Thus, the analysis of ear bone samples represents an excellent long-term monitoring of what kind of waters (e.g., clean versus polluted) fish inhabit.   

Evaluation of mercury and selenium concentrations in fish collected near coal-fired power plants utilizing flue gas desulfurization control technologies (Reash et al., 2015).  The study indicated no evidence of enhanced bioaccumulation in fish for the two metals analyzed, alleviating concerns of regulatory agency staff.

This study evaluated the relationship between fish tissue levels of mercury and selenium in fish collected from coal ash wastewater streams and ambient (unpolluted) locations.  Mercury is a toxicant that can accumulate to harmful levels under certain conditions.  The study found that the accumulation of mercury is reduced when a surplus of selenium is accumulated by fish. This and other studies indicate that selenium, which is a required micronutrient for fish and mammals has important implications for eating fish.