Progress in reducing nutrient and sediment loads to Chesapeake Bay: Three decades of monitoring data and implications for restoring complex ecosystems
Abstract
For over three decades, Chesapeake Bay has been the focal point of a coordinated restoration strategy implemented through a partnership of governmental and nongovernmental entities, which has been a classical model for coastal restoration worldwide. The main objective of this review is to provide resource managers and estuarine scientists with a clearer perspective of the magnitude of changes in water quality within the Bay watershed over this period of restoration, including nitrogen (N), phosphorus (P), and sediment for the River Input Monitoring (RIM) watershed and the unmonitored below-RIM watershed. N load from the RIM watershed has declined in the period of 1985-2017, but P and sediment lacked progress. Reductions of N are largely driven by point sources and atmospheric deposition. Future reductions will require significant progress in managing agricultural nonpoint sources. The below-RIM watershed comprises a disproportionately high fraction of nutrient and sediment inputs to the Bay. Encouragingly, the below-RIM watershed showed long-term declines in major sources, including point sources (N and P), atmospheric deposition (N), manure (N and P) and fertilizer (P). To date, the Bay cleanup efforts have achieved some progress in terms of reducing nutrients from the watershed and improving water quality in the estuary. However, further reductions are critical to achieve the Total Maximum Daily Load goals, and emerging challenges due to Conowingo Reservoir, legacy nutrients, climate change, and population growth should be considered by the Partnership. Continued monitoring, modeling, and assessment are critically important for informing the restoration of Chesapeake Bay and other complex ecosystems.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2022
- Bibcode:
- 2022AGUFM.H15O0973Z