Quantifying the effects of nutrient loading on dissolved O2 cycling and hypoxia in Chesapeake Bay using a coupled hydrodynamic–biogeochemical model

Journal of Marine Systems, Journal Year: 2014, Volume and Issue: 139, P. 139 - 158

Published: June 2, 2014

Language: Английский

---

Spatial, Temporal, and Human-Induced Variations in Suspended Sediment Concentration in the Surface Waters of the Yangtze Estuary and Adjacent Coastal Areas

Estuaries and Coasts, Journal Year: 2012, Volume and Issue: 35(5), P. 1316 - 1327

Published: June 27, 2012

To delineate temporal and spatial variations in suspended sediment concentration (SSC) the Yangtze (Changjiang) Estuary adjacent coastal waters, surface-water samples were taken twice daily from 10 stations over periods ranging 2 to 12 years (total number of >28,000). Synoptic measurements 2009 showed an increase surface SSC 0.058 g/l upper sections estuary ∼0.6 at River turbidity maximum river mouth, decreasing seaward 0.057 g/l. Annual periodicities reflect discharge, which affect horizontal distribution transport SSC, seasonal winds, result vertical resuspension mixing. Over past 10–20 years, annual lower has decreased by 55%, due mainly dam construction middle reaches river. The 20–30% decrease mean waters same period presumably reflects resuspension, part erosion subaqueous Delta. SSCs are expected continue decline as new dams constructed basin delta slows coming decades.

Language: Английский

---

Critical Review of Eutrophication Models for Life Cycle Assessment

Environmental Science & Technology, Journal Year: 2018, Volume and Issue: 52(17), P. 9562 - 9578

Published: July 23, 2018

This paper evaluates the current state of life cycle impact assessment (LCIA) methods used to estimate potential eutrophication impacts in freshwater and marine ecosystems presents a critical review underlying surface water quality, watershed, marine, air fate transport (F&T) models. Using criteria rubric, we assess each method model contribute further refinements (LCA) mechanisms nutrient transformation processes as well structure, availability, geographic scope, spatial temporal resolution. We describe recent advances LCIA modeling provide guidance on best available sources exposure factors, with focus midpoint indicators. The identifies gaps characterization regarding availability resolution factors soil compartment strategies characterize emissions from soil. Additional opportunities are identified leverage detailed F&T models that strengthen existing approaches or have link more closely realities effects eutrophication.

Language: Английский

---

Long term hypoxia suppresses reproductive capacity in the estuarine fish, Fundulus grandis

Comparative Biochemistry and Physiology Part A Molecular & Integrative Physiology, Journal Year: 2007, Volume and Issue: 148(2), P. 317 - 323

Published: May 6, 2007

Language: Английский

---

Assessing temporal and spatial variability of hypoxia over the inner Louisiana–upper Texas shelf: Application of an unstructured-grid three-dimensional coupled hydrodynamic-water quality model

Continental Shelf Research, Journal Year: 2013, Volume and Issue: 72, P. 163 - 179

Published: Aug. 30, 2013

Language: Английский

---

Modeling the mass fluxes and transformations of nutrients in the Pearl River Delta, China

Journal of Marine Systems, Journal Year: 2009, Volume and Issue: 78(1), P. 146 - 167

Published: May 9, 2009

Language: Английский

---

Analysis of spatial and temporal patterns in a large reservoir using water quality and hydrodynamic modeling

Ecological Modelling, Journal Year: 2010, Volume and Issue: 222(14), P. 2485 - 2494

Published: Aug. 20, 2010

Language: Английский

---

Enhancement of sediment suspension and nutrient flux by benthic macrophytes at low biomass

Marine Ecology Progress Series, Journal Year: 2011, Volume and Issue: 448, P. 259 - 270

Published: Dec. 30, 2011

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout JournalEditorsTheme Sections 448:259-270 (2012) - DOI: https://doi.org/10.3354/meps09579 Enhancement of sediment suspension and nutrient flux by benthic macrophytes at low biomass S. E. Lawson*, K. J. McGlathery, P. L. Wiberg Department Environmental Sciences, University Virginia, 291 McCormick Rd., Charlottesville, Virginia 22904, USA *Email: [email protected] ABSTRACT: In shallow coastal ecosystems where most seafloor typically lies within photic zone, autotrophs dominate primary production mediate cycling stability. Because their different structure metabolic rates, 2 functional groups (seagrasses, macroalgae) have distinct influences on benthic−pelagic coupling. Most research date in these soft-bottomed systems has focused mature seagrass meadows shoot densities are high dense macroalgal mats that accumulate response eutrophication. Relatively little is known about influence low-biomass stands macroalgae fluxes suspension. Using an erosion microcosm with controlled forcing conditions, we tested effects eelgrass Zostera marina invasive macroalga Gracilaria vermiculophylla under high-flow conditions. At densities, G. increased from water column. For macroalgae, likely due dislodgement particles bedload transport algae. this case, increase was reflected sediment, showing modification physical producers can also affect flux. The presence or absence Z. did not a significant effect However, results suggest there may be range for which storm-like flows values higher than those expected bare bed. KEY WORDS: Benthic · Sediment Nutrient Seagrass Benthic–pelagic coupling Coastal bay Lagoon Full text pdf format PreviousNextCite article as: Lawson SE, McGlathery KJ, PL biomass. Mar Ecol Prog Ser 448:259-270. Export citation Tweet linkedIn Cited Published Vol. 448. Online publication date: February 23, 2012 Print ISSN: 0171-8630; 1616-1599 Copyright © Inter-Research.

Language: Английский

---

A Deep Learning Model Using Satellite Ocean Color and Hydrodynamic Model to Estimate Chlorophyll-a Concentration

Remote Sensing, Journal Year: 2021, Volume and Issue: 13(10), P. 2003 - 2003

Published: May 20, 2021

In this study, we used convolutional neural networks (CNNs)—which are well-known deep learning models suitable for image data processing—to estimate the temporal and spatial distribution of chlorophyll-a in a bay. The training required construction model acquired from satellite ocean color hydrodynamic model. Chlorophyll-a, total suspended sediment (TSS), visibility, colored dissolved organic matter (CDOM) were extracted data, water level, currents, temperature, salinity generated We developed CNN Model I—which estimates concentration using 48 × 27 sized overall image—and II—which uses 7 segmented image. Because II conducts estimation only around points interest, quantity is more than 300 times larger that I. Consequently, it was possible to extract analyze inherent patterns improving predictive ability average root mean square error (RMSE), calculated by applying II, 0.191, when prediction good, coefficient determination (R2) exceeded 0.91. Finally, performed sensitivity analysis, which revealed CDOM most influential variable estimating spatiotemporal chlorophyll-a.

Language: Английский

---

Sediment resuspension in tidally dominated coastal environments: new insights into the threshold for initial movement

Ocean Dynamics, Journal Year: 2016, Volume and Issue: 66(3), P. 401 - 417

Published: Feb. 12, 2016

Language: Английский

---