T54 Restoring the Nation’s Largest Estuary: Lessons Learned from Efforts to Address Changes in Water Quality and Ecosystem Structure and Function within the Context of Landscape Change and Climate Variability in the Chesapeake Bay and Its Watershed

Sunday, 1 November 2015
1:30 PM - 5:30 PM
Room 308

COMPARING NUTRIENT INPUTS, LAND USE CHANGES, AND IMPLEMENTATION OF BEST MANAGEMENT PRACTICES ACROSS SPACE AND TIME HELPS EXPLAIN CHANGES IN NUTRIENT LOADS TO CHESAPEAKE BAY

Paper number: T54-5
Program: Technical Sessions
Time: 2:25 PM – 2:40 PM

Authors

Abstract

Chesapeake Bay is a eutrophic estuary with periodic hypoxia and anoxia, algal blooms, diminished submerged aquatic vegetation, and degraded stocks of marine life. Efforts to restore the Chesapeake Bay include a suite of management strategies implemented across its watershed designed to reduce nitrogen (N) and phosphorus (P) loads (best management practices or BMPs) to the estuary. A better understanding of the effectiveness of these strategies is needed to support restoration efforts. We compared long-term patterns of anthropogenically derived N and P inputs and BMP implementation to changes in land use and agricultural practices over time and across sub-basins of the Chesapeake Bay watershed. Long-term temporal shifts in agricultural practices (i.e. livestock populations, crop acres, and manure and fertilizer application) and land use change explained changes observed in nutrient inputs. Insights from these comparisons were used to develop hypotheses regarding potential drivers of changes in water quality. Cross-watershed comparison improved the ability to focus analysis and the reporting of results on sub-watersheds with the greatest potential to inform those management strategies designed for nutrient reduction.