; (6) existing broad-scale data sets are important but insufficient to track changes in mercury levels in the environment over time, test model predictions, and assess the impact of changing mercury emissions and deposition; and (7) a comprehensive national mercury monitoring network to accurately quantify regional and national changes in atmospheric mercury deposition, ecosystem contamination, and bioaccumulation of mercury in fish and wildlife in response to changes in mercury emissions would help policy makers, scientists, and the public to better understand the sources, consequences, and trends of mercury pollution in the United States. 3. Definitions In this Act: (1) Administrator The term Administrator means the Administrator of the Environmental Protection Agency. (2) Advisory committee The term Advisory Committee means the Mercury Monitoring Advisory Committee established under section 5(a). (3) Ancillary measure The term ancillary measure means a measure that is used to understand the impact and interpret results of measurements under the program. (4) Ecoregion The term ecoregion means a large area of land and water that contains a geographically distinct assemblage of natural communities, including similar land forms, climate, ecological processes, and vegetation. (5) Mercury export The term mercury export means mercury transport from a watershed to the corresponding body of water, or from 1 body of water to another body of water (such as from a lake to a river), generally expressed as— (A) mass per unit of time; or (B) mass per unit of watershed or body of water area per unit of time. (6) Mercury flux The term mercury flux means the rate of transfer of mercury between ecosystem components (such as between water and air or land and air) or between portions of ecosystem components, expressed in terms of— (A) mass per unit of time