Virginia Institute of Marine Science
Excessive nitrogen can enter estuarine and coastal areas from land, disturbing coastal ecosystems and causing serious environmental problems. The Chesapeake Bay is one of the regions that have experienced hypoxia and harmful algal blooms in recent decades. This study estimated nitrogen export from the Chesapeake Bay watershed (CBW) to the estuary from 1900 to 2015 by applying a state-of-the-art numerical model. Nitrogen loading from the CBW continually increased from the 1900s to the 1990s and has declined since then. The key contributors to nitrogen export have shifted from atmospheric nitrogen deposition (before the 1960s) to synthetic nitrogen fertilizer (after the 1980s). Antipollution policies and implementation measures have played critical roles in the decrease of nitrogen export since the 1980s, and further reduction in riverine nitrogen export will likely require regulation on the application of nitrogen fertilizer.
© 2021. American Geophysical Union.
Pan, Shufen; Bian, Zihao; (...); Friedrichs, Marjorie A.M.; and et al, Impacts of Multiple Environmental Changes on Long- Term Nitrogen Loading From the Chesapeake Bay Watershed (2021). JGR Biogeosciences, 126(5), e2020JG005826.