IAN is committed to producing practical, user-centered communications that foster a better understanding of science and enable readers to pursue new opportunities in research, education, and environmental problem-solving. Our publications synthesize scientific findings using effective science communication techniques.

Evaluation of statistical methods for quantifying fractal scaling in water-quality time series with irregular sampling (Page 1)

Evaluation of statistical methods for quantifying fractal scaling in water quality time series with irregular sampling

Zhang Q, Harman CJ, Kirchner JW ·
2018

River water-quality time series often exhibit fractal scaling, which here refers to autocorrelation that decays as a power law over some range of scales. Fractal scaling presents challenges to the identification of deterministic trends because (1) fractal scaling has the potential to lead to false inference about the statistical significance of trends and (2) the abundance of irregularly spaced data in water-quality monitoring networks complicates efforts to quantify fractal scaling.

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Watershed export of fine sediment, organic carbon, and chlorophyll-a to Chesapeake Bay: Spatial and temporal patterns in 1984–2016 (Page 1)

Watershed export of fine sediment, organic carbon, and chlorophyll-a to Chesapeake Bay: Spatial and temporal patterns in 1984–2016

Zhang Q, and Blomquist JD ·
2018

Chesapeake Bay has long experienced nutrient enrichment and water clarity deterioration. This study provides new quantification of loads and yields for sediment (fine and coarse grained), organic carbon (total, dissolved, and particulate), and chlorophyll-a from the monitored nontidal Chesapeake Bay watershed (MNTCBW), all of which are expected to drive estuarine water clarity.

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Synthesis of nutrient and sediment export patterns in the Chesapeake Bay watershed: Complex and non-stationary concentration-discharge relationships (Page 1)

Synthesis of nutrient and sediment export patterns in the Chesapeake Bay watershed: Complex and non-stationary concentration-discharge relationships

Zhang Q ·
2018

Derived from river monitoring data, concentration-discharge (C-Q) relationships are useful indicators of riverine export dynamics. A top-down synthesis of C-Q patterns was conducted for suspended sediment (SS), total phos- phorus (TP), and total nitrogen (TN) for nine major tributaries (15 monitoring sites) to Chesapeake Bay, which represent diverse characteristics in terms of land use, physiography, and hydrological settings.

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Seagrass ecosystem trajectory depends on the relative timescales of T resistance, recovery and disturbance (Page 1)

Seagrass ecosystem trajectory depends on the relative timescales of T resistance, recovery and disturbance

O'Briena KR, Waycott M, Maxwell P, Kendrick GA, Udy JW, Ferguson A JP, Kilminster K, Scanes P, McKenzie LJ, McMahon K, Adams MP, Samper-Villarreal J, Collier C, Lyons M, Mumby PJ, Radke L, Christianen M JA, and Dennison WC ·
2017

Seagrass ecosystems are inherently dynamic, responding to environmental change across a range of scales. Habitat requirements of seagrass are well defined, but less is known about their ability to resist disturbance. Specific means of recovery after loss are particularly difficult to quantify. Here we assess the resistance and recovery capacity of 12 seagrass genera.

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Long-term nutrient reductions lead to the unprecedented recovery of a temperate coastal region (Page 1)

Long-term nutrient reductions lead to the unprecedented recovery of a temperate coastal region

Lefcheck JS, Orth RJ, Dennison WC, Wilcox DJ, Murphy RR, Keisman J, Gurbisz C, Hannam M, Landry JB, Moore KA, Patrick CJ, Testa J, Weller DE, and Batiuk RA ·
2017

Humans strongly impact the dynamics of coastal systems, yet surprisingly few studies mechanistically link management of anthropogenic stressors and successful restoration of nearshore habitats over large spatial and temporal scales. Such examples are sorely needed to ensure the success of ecosystem restoration efforts worldwide.

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Ecological Forecasting and the Science of Hypoxia in Chesapeake Bay (Page 1)

Ecological Forecasting and the Science of Hypoxia in Chesapeake Bay

Testa JM, Clark JB, Dennison WC, Donovan EC, Fisher AW, Ni W, Parker M, Scavia D, Spitzer SE, Waldrop AM, Vargas V, And Ziegler G ·
2017

Chronic seasonal low oxygen condition (hypoxia) occurs in the deep waters of Chesapeake Bay as a result of eutrophication-induced phytoplankton blooms and their subsequent decomposition. Summertime hypoxia has been observed in Chesapeake Bay for over 80 years, with scientific attention and understanding increasing substantially during the past several decades after rigorous and routine monitoring programs were put in place.

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Submersed Aquatic Vegetation in Chesapeake Bay: Sentinel Species in a Changing World (Page 1)

Submersed Aquatic Vegetation in Chesapeake Bay: Sentinel Species in a Changing World

Orth RJ, Dennison WC, Lefcheck JS, Gurbisz C, Hannam M, Keisman J, Landry JB, Moore KA, Murphy RR, Patrick CJ, Testa J, Weller DE, And Wilcox DJ ·
2017

Chesapeake Bay has undergone profound changes since European settlement. Increases in human and livestock populations, associated changes in land use, increases in nutrient loadings, shoreline armoring, and depletion of fish stocks have altered the important habitats within the Bay. Submersed aquatic vegetation (SAV) is a critical foundational habitat and provides numerous benefits and services to society.

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Improving riverine constituent concentration and flux estimation by accounting for antecedent discharge conditions (Page 1)

Improving riverine constituent concentration and flux estimation by accounting for antecedent discharge conditions

Zhang Q, Ball WP ·
2017

Regression-based approaches are often employed to estimate riverine constituent concentrations and fluxes based on typically sparse concentration observations. One such approach is the recently developed WRTDS (“Weighted Regressions on Time, Discharge, and Season”) method, which has been shown to provide more accurate estimates than prior approaches in a wide range of applications.

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Numerical and Qualitative Contrasts of Two Statistical Models for Water Quality Change in Tidal Waters (Page 1)

Numerical and Qualitative Contrasts of Two Statistical Models for Water Quality Change in Tidal Waters

Beck MW and Murphy RR ·
2017

Two statistical approaches, weighted regression on time, discharge, and season and generalized addi- tive models, have recently been used to evaluate water quality trends in estuaries. Both models have been used in similar contexts despite differences in statistical foundations and products. This study provided an empirical and qualitative comparison of both models using 29 years of data for two discrete time series of chlorophyll-a (chl-a) in the Patuxent River estuary.

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Assessing water quality of the Chesapeake Bay by the impact of sea level rise and warming (Page 1)

Assessing water quality of the Chesapeake Bay by the impact of sea level rise and warming

Wang P,Linker L, Wang H, Bhatt G, Yactayo G, K Hinson K and Tian R ·
2017

The influence of sea level rise and warming on circulation and water quality of the Chesapeake Bay under projected climate conditions in 2050 were estimated by computer simulation. Four estuarine circulation scenarios in the estuary were run using the same watershed load in 1991-2000 period. They are, 1) the Base Scenario, which represents the current climate condition, 2) a Sea Level Rise Scenario, 3) a Warming Scenario, and 4) a combined Sea Level Rise and Warming Scenario.

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