Article
Biodiversity Conservation
A. R. Zahran, Q. Zhang, P. Tango, E. P. Smith
Summary: This paper develops a barometer that indexes water quality in the Chesapeake Bay and summarizes it over spatial regions and temporal periods. The barometer is based on risk assessment and hydrology, and calculates three different metrics of water quality relative to numerical criteria. The barometer score is a geometric mean of these three metrics. The paper evaluates water quality using dissolved oxygen measurements collected in the Chesapeake Bay during the summer seasons from 1985 to 2020, and reports the barometer score at different levels.
ECOLOGICAL INDICATORS
(2022)
Article
Environmental Sciences
Luke T. Frankel, Marjorie A. M. Friedrichs, Pierre St-Laurent, Aaron J. Bever, Romuald N. Lipcius, Gopal Bhatt, Gary W. Shenk
Summary: The study found that nitrogen reductions since 1985 have decreased hypoxia in Chesapeake Bay, but the improvement from nitrogen reductions was offset by Bay warming, thus the actual effect of nitrogen reductions was smaller than expected. This indicates that greater reductions are needed to counteract the ever-increasing impacts of climate change.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
S. Y. Chang, Q. Zhang, D. K. Byrnes, N. B. Basu, K. J. Van Meter
Summary: Efforts to reduce nitrogen inputs in the Chesapeake Bay have shown some progress, with recent improvements in water quality attributed to decreases in nitrogen surplus magnitudes. Despite slow improvement, goals to reduce nitrogen loads by 25% across the region may be met within the next two decades even with no additional changes in current management practices. Time lags in achieving water quality goals may vary across different watersheds, with the longest delays seen in highly agricultural areas where legacy nitrogen continues to impact water quality.
ENVIRONMENTAL RESEARCH LETTERS
(2021)
Article
Oceanography
Jessica S. Turner, Carl T. Friedrichs, Marjorie A. M. Friedrichs
Summary: While ecosystem health is improving in many estuaries worldwide following nutrient reductions, inconsistent trends in water clarity often remain. The study in Chesapeake Bay found that some measurements of downstream estuarine water clarity appear to be uncorrelated with watershed management actions, indicating the need for multiple metrics to address the issue. Satellite remote sensing provides an additional tool to assess long-term change in water clarity.
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS
(2021)
Article
Environmental Sciences
Ryan E. Langendorf, Vyacheslav Lyubchich, Jeremy M. Testa, Qian Zhang
Summary: This study demonstrates the use of environmental monitoring programs to better understand and manage complex ecosystems, using surface water dissolved oxygen criteria attainment in the Chesapeake Bay as a case study. The research revealed contrasting controls on dissolved oxygen across different regions, with factors such as summer freshwater and sediment inputs impacting attainment differently in landward and open waters, and algae biomass showing opposite effects in surface and deep waters.
Article
Environmental Sciences
Bushra Tasnim, Xing Fang, Joel S. Hayworth, Di Tian
Summary: This study improved the water quality model MINLAKE2020 to better simulate the internal nutrient dynamics of six lakes in Minnesota, revealing the impact of phosphorus release from sediment on surface phosphorus concentration in lakes.
Article
Environmental Sciences
R. J. Fox, T. R. Fisher, A. B. Gustafson, E. L. Koontz, M. Lepori-Bui, K. L. Kvalnes, D. E. Bunnell-Young, J. R. Gardner, J. Lewis, J. R. Winsten, K. A. Fisher, K. Silaphone
Summary: The study found that the current management approach of primarily voluntary, untargeted BMP implementation is insufficient to achieve detectable, widespread reductions in N, P, and TSS concentrations in agricultural watersheds of the Choptank basin. Greater outreach and more financial support for farmers to implement BMPs are required to achieve regional water quality goals.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2021)
Article
Engineering, Environmental
Carl F. Cerco, Richard Tian
Summary: The addition of a predictive wetlands module to an existing eutrophication model in Chesapeake Bay evaluates the impact of wetlands loss and migration on dissolved oxygen standards. The results indicate two main risks to DO standards.
JOURNAL OF THE AMERICAN WATER RESOURCES ASSOCIATION
(2022)
Article
Engineering, Marine
Timothy T. Wynne, Michelle C. Tomlinson, Travis O. Briggs, Sachidananda Mishra, Andrew Meredith, Ronald L. Vogel, Richard P. Stumpf
Summary: This manuscript describes methods for evaluating the efficacy of five satellite-based Chlorophyll-a algorithms in Chesapeake Bay. The results show that a two-band algorithm based on the red-edge portion of the electromagnetic spectrum exhibited the lowest overall error when applied to OLCI imagery.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2022)
Article
Environmental Sciences
Seema Nihalani, Ashish Meeruty
Summary: The study examined the water quality index of four rivers in Gujarat, indicating that most of the surface water samples ranged from good to poor. The quality of water was better upstream compared to downstream, with the decline attributed to sewage discharge, industrial effluent, and urban runoff.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2021)
Article
Environmental Sciences
Stephanie Gordon, Tyler Wagner, Kelly Smalling, Olivia Devereux
Summary: Best management practices (BMPs) have been successful in reducing nutrient and sediment loads entering the Chesapeake Bay watershed. A study found that BMP intensity on agricultural land can reduce total estrogenic activity. Additionally, watersheds with high agriculture and low BMPs have a higher probability of exceeding an effects-based threshold.
JOURNAL OF ENVIRONMENTAL MANAGEMENT
(2023)
Article
Environmental Sciences
Wei Zhi, Christoph Klingler, Jiangtao Liu, Li Li
Summary: This study reconstructed daily water temperature and dissolved oxygen in rivers across the United States and Central Europe using a deep learning model. The results showed that a majority of the rivers experienced persistent warming and deoxygenation, with urban rivers exhibiting the most rapid warming and agricultural rivers experiencing the slowest warming but fastest deoxygenation.
NATURE CLIMATE CHANGE
(2023)
Article
Environmental Sciences
Piero L. F. Mazzini, Cassia Pianca
Summary: The study analyzed over three decades of temperature records in the Chesapeake Bay and found that on average, marine heatwaves (MHWs) occurred twice per year, lasting 11 days each time. This could have detrimental effects on the bay's ecosystem if trends continue.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Environmental Sciences
Thomas R. Fisher, Rebecca J. Fox, Anne B. Gustafson, Erika Koontz, Michelle Lepori-Bui, James Lewis
Summary: Improvements in water quality in the Choptank tributary of Chesapeake Bay were likely due to reductions in atmospheric deposition and wastewater treatment upgrades, with minimal contributions from the agricultural sector during the studied period. Efforts in reducing nutrient losses from agriculture could potentially lead to significant improvements in water quality throughout the estuary.
ESTUARIES AND COASTS
(2021)
Article
Environmental Sciences
Shufen Pan, Zihao Bian, Hanqin Tian, Yuanzhi Yao, Raymond G. Najjar, Marjorie A. M. Friedrichs, Eileen E. Hofmann, Rongting Xu, Bowen Zhang
Summary: This study examined nitrogen export from the Chesapeake Bay watershed since 1900 and found that the export of ammonium and nitrate increased until the 1990s and then declined. Precipitation was the primary driver of interannual variability in nitrogen export, while wastewater discharge explained most of the long-term changes in ammonium and organic nitrogen fluxes. Atmospheric deposition, wastewater, and synthetic fertilizer were responsible for the trend of nitrate export. Management of terrestrial non-point source nutrients will be crucial in achieving water quality goals.
JOURNAL OF GEOPHYSICAL RESEARCH-BIOGEOSCIENCES
(2021)