Investigators at CBPO Analyze Thirty Years of Water Quality Attainment Data
Seven authors working with the Chesapeake Bay Program partnership have recently published two papers describing their analysis of three decades of water quality criteria attainment data in the Chesapeake Bay. The authors — Qian Zhang (EPA-CBPO/UMCES), Rebecca R. Murphy (EPA-CBPO/UMCES), Richard Tian (EPA-CBPO), Melinda K. Forsyth (UMCES-CBL), Emily M. Trentacoste  (EPA-CBPO), Jennifer Keisman (USGS MD-DE-DC Water Science Center) and Peter J. Tango (USGS-CBPO) — have been working together for the past three years on this effort, aided by US EPA Technical Support funding.

In one of the papers (published in Science of the Total Environment), the authors report on a “mulitmetric indicator assessment” over the period 1985-2016 and conclude that the results indicate that the Bay has been “recovering since 1985” and that “the improvement in estimated Baywide attainment was statistically linked to the decline of total nitrogen.”  They take these results to “indicat[e] responsiveness of attainment status to the reduction of nutrient load through various management actions since at least the 1980s.”

In the second paper (published in Frontiers in Marine Science), the authors report on dissolved oxygen attainment data, and the results suggest there has been a “general lack of significantly improving trends across the Bay” and that this “suggests further actions will be necessary to achieve full attainment of DO criterion.” They also point out, however, that the effort has provided insights that are “are critical for understanding the dynamics of the Bay ecosystem and for further assessing the effectiveness of management initiatives aimed toward Bay restoration.”

The two papers are:

Zhang, Q., R.R. Murphy, R. Tian, M.K. Forsyth, E.M. Trentacoste, J. Keisman, and P.J. Tango, “Chesapeake Bay’s water quality condition has been recovering: Insights from a multimetric indicator assessment of thirty years of tidal monitoring data,” Science of The Total Environment, Vols. 637–638, pp 1617-1625 (2018).[https://doi.org/10.1016/j.scitotenv.2018.05.025]

Zhang, Q., P.J. Tango, R.R. Murphy, M.K. Forsyth, R. Tian, J. Keisman, and E.M. Trentacoste, “Chesapeake Bay Dissolved Oxygen Criterion Attainment Deficit: Three Decades of Temporal and Spatial Patterns,” Frontiers in Marine Science, vol 5, article 422 (2018). [https://doi.org/10.3389/fmars.2018.00422]