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Long-Term Trends for Surface Orthophosphate in the Chesapeake Bay: 1999-2013

Long-term trends were computed by state partners using the Seasonal Kendall non-parametric technique for annual data collected from 1999-2013. Highly significant trends are indicated with triangles and possible trends are show with colored circles. Surface Orthophosphate concentrations are decreasing/improving significantly at 29 stations, possibly decreasing at 7 stations, increasing/degrading significantly at 5 stations, and possibly increasing at 2 stations.

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Long-Term Trends for Surface Total Nitrogen in the Chesapeake Bay: 1999-2013

Long-term trends were computed by state partners using the Seasonal Kendall non-parametric technique for annual data collected from 1999-2013. Highly significant trends are indicated with triangles and possible trends are show with colored circles. Surface total nitrogen concentrations are decreasing/improving significantly at 41 stations, possibly decreasing at 16 stations, increasing/degrading significantly at 1 station, and possibly increasing at 1 station.

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Long-Term Trends for Surface Chlorophyll-a in the Chesapeake Bay: 1999-2013

Long-term trends were computed by state partners using the Seasonal Kendall non-parametric technique for annual data collected from 1999-2013. Highly significant trends are indicated with triangles and possible trends are show with colored circles. Surface chlorophyll-a concentrations are decreasing/improving significantly at 2 stations, possibly decreasing at 7 stations, increasing/degrading significantly at 25 stations, and possibly increasing at 16 stations.

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Shad Abundance (2014)

American shad were once the most abundant and economically important species in the Chesapeake Bay. Shad are anadromous fish and spend most of their lives in the ocean, returning to freshwater rivers to spawn after they reach maturity. Data for the York, Potomac, Rappahannock and lower James Rivers were provided by the Virginia Institute of Marine Science via an ongoing Catch per Unit Effort (CPUE) study involving American Shad gill-netting. Data for the Susquehanna and upper James Rivers represent published fishway passage values for Conowingo and Boshers Dams, respectively.

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Short-Term Trend in Flow-Adjusted Total Suspended Solids Concentration, 2004-2013

Over the past decade, none of the monitoring sites in the Chesapeake Bay watershed have shown improving flow-adjusted trends in sediment concentrations. Between 2004 and 2013: zero sites have shown improving trends for sediment concentrations. Four sites—including the Appomattox, Choptank, Pamunkey and Patuxent rivers—have shown degrading trends. Five sites—including the James, Mattaponi, Potomac, Rappahannock and Susquehanna rivers—have shown minor changes that are not statistically significant.

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Long Term Flow-Adjusted Trends in Sediment, 1985-2013

One-third of the monitoring sites in the Chesapeake Bay watershed show improving long-term flow-adjusted trends in suspended sediment concentrations. Between 1985 and 2013: three out of nine sites—including the Choptank, Patuxent and Potomac rivers—have shown improving trends for sediment concentrations. One site—the Pamunkey River—has shown degrading trends. Five sites—including the Appomattox, James, Mattaponi, Rappahannock and Susquehanna rivers—have shown minor changes that are not statistically significant.

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Short-Term Trend in Flow-Adjusted Total Phosphorus Concentration, 2004-2013

Over the past decade, none of the monitoring sites in the Chesapeake Bay watershed have shown improving flow-adjusted trends in phosphorus concentrations. Between 2004 and 2013: zero sites have shown improving trends for phosphorus concentrations. Two sites—including the Choptank and Susquehanna rivers—have shown degrading trends. Seven sites—including the Appomattox, James, Mattaponi, Pamunkey, Patuxent, Potomac and Rappahannock rivers—have shown minor changes that are not statistically significant.

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Long-Term Trend in Flow-Adjusted Total Phosphorus Concentration, 1985-2013

One-third of the monitoring sites in the Chesapeake Bay watershed show improving long-term flow-adjusted trends in phosphorus concentrations. Between 1985 and 2013: three out of nine sites—including the James, Patuxent and Potomac rivers—have shown improving trends for phosphorus concentrations. Three sites— including the Appomattox, Choptank and Pamunkey rivers—have shown degrading trends. Three sites—including the Mattaponi, Rappahannock and Susquehanna rivers—have shown minor changes that are not statistically significant.

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Short-Term Trend in Flow-Adjusted Total Nitrogen Concentration, 2004-2013

Over the past decade, one-third of the monitoring sites in the Chesapeake Bay watershed have shown improving flow-adjusted trends in nitrogen concentrations. Between 2004 and 2013: three out of nine sites—including the Patuxent, Potomac and Susquehanna rivers—have shown improving trends for nitrogen concentrations. One site—the Choptank River—has shown degrading trends. Five sites—including the Appomattox, James, Mattaponi, Rappahannock and Pamunkey rivers—have shown minor changes that are not statistically significant.

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