Chesapeake Bay Dissolved Oxygen Criterion Attainment Deficit

Description

Low dissolved oxygen (DO) conditions are a recurring issue in the waters of the Chesapeake Bay, with detrimental effects on aquatic living resources. The Chesapeake Bay Program partnership has developed criteria guidance supporting the definition of state water quality standards and associated assessment procedures for DO and other parameters, which provides a binary classification of attainment or impairment. Evaluating time series of these two outcomes alone, however, provides limited information on water quality change over time or space. This study, published in Frontiers in Marine Science, introduced an extension of the existing Chesapeake Bay water quality criterion assessment framework to quantify the amount of impairment shown by space-time exceedance of DO criterion (“attainment deficit”) for a specific tidal management unit (i.e., segment). We demonstrate the usefulness of this extended framework by applying it to Bay segments for each 3-year assessment period between 1985 and 2016. Insights revealed in this work are critical for understanding the dynamics of the Bay ecosystem and for further assessing the effectiveness of management initiatives aimed toward Bay restoration.

Citation

Zhang, Q., P.J. Tango, R.R. Murphy, M.K. Forsyth, R. Tian, J. Keisman, and E.M. Trentacoste, 2018. “Chesapeake Bay dissolved oxygen criterion attainment deficit: Three decades of temporal and spatial patterns”, Frontiers in Marine Science, 5: 422, doi: 10.3389/fmars.2018.00422.