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A Communal Catalogue Reveals Earth’S Multiscale Microbial Diversity, Luke R. Thompson, Jon G. Saunders, Et Al, Earth Microbiome Project Consortium, Donglai Gong
A Communal Catalogue Reveals Earth’S Multiscale Microbial Diversity, Luke R. Thompson, Jon G. Saunders, Et Al, Earth Microbiome Project Consortium, Donglai Gong
VIMS Articles
Our growing awareness of the microbial world's importance and diversity contrasts starkly with our limited understanding of its fundamental structure. Despite recent advances in DNA sequencing, a lack of standardized protocols and common analytical frameworks impedes comparisons among studies, hindering the development of global inferences about microbial life on Earth. Here we present a meta-analysis of microbial community samples collected by hundreds of researchers for the Earth Microbiome Project. Coordinated protocols and new analytical methods, particularly the use of exact sequences instead of clustered operational taxonomic units, enable bacterial and archaeal ribosomal RNA gene sequences to be followed across multiple …
Comparisons Of Different Instruments For Measuring Suspended Cohesive Sediment Concentrations, Yy Shao, Jpy Maa
Comparisons Of Different Instruments For Measuring Suspended Cohesive Sediment Concentrations, Yy Shao, Jpy Maa
VIMS Articles
Laboratory experiments were conducted to compare the performances of four different instruments for measuring suspended cohesive sediment concentrations (SSCs). Among these instruments, two were different models of optical backscatter sensor (i.e., OBS3+ and OBS5+), one was an acoustic Doppler velocimeter (MicroADV), and the last was a laser infrared optical sensor developed at Hohai University, China (HHU-LIOS). Sediments collected from the Yangtze River Estuary and a commercially available kaolinite were selected to check the responses of these four instruments. They were placed in an aqueous solution, and the SSCs were changed within a range from about 10 mg/L to 30 g/L …
Seasonal Nitrogen Uptake And Regeneration In The Western Coastal Arctic, Se Baer, Rachel E. Sipler, Qn Roberts, Pl Yager, Me Frischer, D Bronk
Seasonal Nitrogen Uptake And Regeneration In The Western Coastal Arctic, Se Baer, Rachel E. Sipler, Qn Roberts, Pl Yager, Me Frischer, D Bronk
VIMS Articles
Here, we present the first study to investigate the seasonal importance of amino acid-nitrogen (N) to Arctic near shore microbial communities. We measured primary productivity and the uptake of ammonium, nitrate, urea, and amino acids in two size fractions (> 3 m and approximately 0.7-3 m), as well as ammonium regeneration and nitrification using N-15 and C-13 tracer approaches in the near-shore waters of the Chukchi Sea, during January, April, and August for two consecutive years. At discrete depths, nitrate comprised 46-78% of the total dissolved N pool during January and April but only 2-6% during August. Dissolved organic N …
Assessing Water Quality Of The Chesapeake Bay By The Impact Of Sea Level Rise And Warming, P Wang, L Linker, Harry V. Wang, G Bhatt, G Yactayo, K Hinson, R Tian
Assessing Water Quality Of The Chesapeake Bay By The Impact Of Sea Level Rise And Warming, P Wang, L Linker, Harry V. Wang, G Bhatt, G Yactayo, K Hinson, R Tian
VIMS Articles
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. With a 1.6-1.9 degrees C increase in monthly air temperatures in the Warming Scenario, water temperature in the Bay is estimated to increase …
Ensemble Modeling Informs Hypoxia Management In The Northern Gulf Of Mexico, D Scavia, I Bertani, Dr Obenour, Re Turner, David R. Forrest, A Katin
Ensemble Modeling Informs Hypoxia Management In The Northern Gulf Of Mexico, D Scavia, I Bertani, Dr Obenour, Re Turner, David R. Forrest, A Katin
VIMS Articles
A large region of low-dissolved-oxygen bottom waters (hypoxia) forms nearly every summer in the northern Gulf of Mexico because of nutrient inputs from theMississippi River Basin andwater column stratification. Policymakers developed goals to reduce the area of hypoxic extent because of its ecological, economic, and commercial fisheries impacts. However, the goals remain elusive after 30 y of research and monitoring and 15 y of goal-setting and assessment because there has been little change in river nitrogen concentrations. An intergovernmental Task Force recently extended to 2035 the deadline for achieving the goal of a 5,000-km(2) 5-y average hypoxic zone and set …
Lateral Vegetation Growth Rates Exert Control On Coastal Foredune "Hummockiness" And Coalescing Time, Eb Goldstein, Lj Moore, Od Vinent
Lateral Vegetation Growth Rates Exert Control On Coastal Foredune "Hummockiness" And Coalescing Time, Eb Goldstein, Lj Moore, Od Vinent
VIMS Articles
Coastal foredunes form along sandy, low-sloped coastlines and range in shape from continuous dune ridges to hummocky features, which are characterized by alongshore-variable dune crest elevations. Initially scattered dune-building plants and species that grow slowly in the lateral direction have been implicated as a cause of foredune "hummockiness". Our goal in this work is to explore how the initial configuration of vegetation and vegetation growth characteristics control the development of hummocky coastal dunes including the maximum hummockiness of a given dune field. We find that given sufficient time and absent external forcing, hummocky foredunes coalesce to form continuous dune ridges. …
Preliminary Estimate Of Contribution Of Arctic Nitrogen Fixation To The Global Nitrogen Budget, Rachel E. Sipler, Donglai Gong, Se Baer, Mp Sanderson, Qn Roberts, M Mulholland, Da Bronk
Preliminary Estimate Of Contribution Of Arctic Nitrogen Fixation To The Global Nitrogen Budget, Rachel E. Sipler, Donglai Gong, Se Baer, Mp Sanderson, Qn Roberts, M Mulholland, Da Bronk
VIMS Articles
Dinitrogen (N-2) fixation is the source of all biologically available nitrogen on earth, and its presence or absence impacts net primary production and global biogeochemical cycles. Here, we report rates of 3.5-17.2 nmol N L-1 d(-1) in the ice-free coastal Alaskan Arctic to show that N-2 fixation in the Arctic Ocean may be an important source of nitrogen to a seasonally nitrogen-limited system. If widespread in surface waters over ice-free shelves throughout the Arctic, N-2 fixation could contribute up to 3.5 Tg N yr(-1) to the Arctic nitrogen budget. At these rates, N-2 fixation occurring in ice-free summer waters would …
Microbial Community Response To Terrestrially Derived Dissolved Organic Matter In The Coastal Arctic, Rachel E. Sipler, Colleen T. E. Kellogg, Tara L. Connelly, Qn Roberts, Patricia L. Yager, Deborah A. Bronk
Microbial Community Response To Terrestrially Derived Dissolved Organic Matter In The Coastal Arctic, Rachel E. Sipler, Colleen T. E. Kellogg, Tara L. Connelly, Qn Roberts, Patricia L. Yager, Deborah A. Bronk
VIMS Articles
Warming at nearly twice the global rate, higher than average air temperatures are the new 'normal' for Arctic ecosystems. This rise in temperature has triggered hydrological and geochemical changes that increasingly release carbon-rich water into the coastal ocean via increased riverine discharge, coastal erosion, and the thawing of the semipermanent permafrost ubiquitous in the region. To determine the biogeochemical impacts of terrestrially derived dissolved organic matter (tDOM) on marine ecosystems we compared the nutrient stocks and bacterial communities present under ice-covered and ice-free conditions, assessed the lability of Arctic tDOM to coastal microbial communities from the Chukchi Sea, and identified …
Chemical And Photophysiological Impact Of Terrestrially-Derived Dissolved Organic Matter On Nitrate Uptake In The Coastal Western Arctic, Rachel E. Sipler, Se Baer, Tl Connelly, Me Frischer, Qn Roberts, Pl Yager, Da Bronk
Chemical And Photophysiological Impact Of Terrestrially-Derived Dissolved Organic Matter On Nitrate Uptake In The Coastal Western Arctic, Rachel E. Sipler, Se Baer, Tl Connelly, Me Frischer, Qn Roberts, Pl Yager, Da Bronk
VIMS Articles
The Arctic is warming at a rate nearly twice the global average, leading to thawing permafrost, increased coastal erosion, and enhanced delivery of riverine terrestrially-derived dissolved organic matter (tDOM) to coastal waters. This humic-rich tDOM has the ability to attenuate light required for photosynthesis and stimulate heterotrophic growth by supplying a source of labile organic carbon. Due to tDOM's high carbon to nitrogen (C : N) ratio, additional nitrogen is required for microorganisms to utilize this excess carbon for growth, thus exacerbating competition between autotrophs and heterotrophs for limiting nutrients and potentially reducing primary production. The effect of Arctic tDOM …
A Synergistic Approach For Evaluating Climate Model Output For Ecological Applications, Rochelle Cavanaugh, Ej Murphy, Et Al, Walker O. Smith Jr., Et Al
A Synergistic Approach For Evaluating Climate Model Output For Ecological Applications, Rochelle Cavanaugh, Ej Murphy, Et Al, Walker O. Smith Jr., Et Al
VIMS Articles
Increasing concern about the impacts of climate change on ecosystems is prompting ecologists and ecosystem managers to seek reliable projections of physical drivers of change. The use of global climate models in ecology is growing, although drawing ecologically meaningful conclusions can be problematic. The expertise required to access and interpret output from climate and earth system models is hampering progress in utilizing them most effectively to determine the wider implications of climate change. To address this issue, we present a joint approach between climate scientists and ecologists that explores key challenges and opportunities for progress. As an exemplar, our focus …
Interactive Effects Of Elevated Temperature And Co2 On Nitrate, Urea, And Dissolved Inorganic Carbon Uptake By A Coastal California, Usa, Microbial Community, Jl Spackeen, Rachel E. Sipler, K Xu, Et Al, Da Bronk
Interactive Effects Of Elevated Temperature And Co2 On Nitrate, Urea, And Dissolved Inorganic Carbon Uptake By A Coastal California, Usa, Microbial Community, Jl Spackeen, Rachel E. Sipler, K Xu, Et Al, Da Bronk
VIMS Articles
Average global temperatures and carbon dioxide (CO2) levels are expected to increase in the coming decades. Implications for ocean ecosystems include shifts in microbial community structure and subsequent modifications to nutrient pathways. Studying how predicted future temperature and CO2 conditions will impact the biogeochemistry of the ocean is important because of the ocean’s role in regulating global climate. We determined how elevated temperature and CO2 affect uptake rates of nitrate, urea, and dissolved inorganic carbon (DIC) by 2 size classes (0.7-5.0 and >5.0 µm) of a microbial assemblage collected from coastal California, USA. This microbial community was incubated for 10 …
Vegetation Recovery In Tidal Marshes Reveals Critical Slowing Down Under Increased Inundation, Jim Van Belzen, Johan Van De Koppel, Matthew L. Kirwan, Daphne Van Der Wal, Peter M.J. Herman, Vasilis Dakos, Sonia Kefi, Marten Scheffer, Glenn R. Guntenspergen, Tjeerd J. Bouma
Vegetation Recovery In Tidal Marshes Reveals Critical Slowing Down Under Increased Inundation, Jim Van Belzen, Johan Van De Koppel, Matthew L. Kirwan, Daphne Van Der Wal, Peter M.J. Herman, Vasilis Dakos, Sonia Kefi, Marten Scheffer, Glenn R. Guntenspergen, Tjeerd J. Bouma
VIMS Articles
A declining rate of recovery following disturbance has been proposed as an important early warning for impending tipping points in complex systems. Despite extensive theoretical and laboratory studies, this 'critical slowing down' remains largely untested in the complex settings of real-world ecosystems. Here, we provide both observational and experimental support of critical slowing down along natural stress gradients in tidal marsh ecosystems. Time series of aerial images of European marsh development reveal a consistent lengthening of recovery time as inundation stress increases. We corroborate this finding with transplantation experiments in European and North American tidal marshes. In particular, our results …
Created Mangrove Wetlands Store Belowground Carbon And Surface Elevation Change Enables Them To Adjust To Sea-Level Rise, Ken W. Krauss, Nicole Cormier, Michael J. Osland, Matthew L. Kirwan, Camille L. Stagg, Janet A. Nestlerode, Marc J. Russell, Andrew S. From, Amanda C. Spivak, Darrin D. Dantin, James E. Harvey, Alejandro E. Almario
Created Mangrove Wetlands Store Belowground Carbon And Surface Elevation Change Enables Them To Adjust To Sea-Level Rise, Ken W. Krauss, Nicole Cormier, Michael J. Osland, Matthew L. Kirwan, Camille L. Stagg, Janet A. Nestlerode, Marc J. Russell, Andrew S. From, Amanda C. Spivak, Darrin D. Dantin, James E. Harvey, Alejandro E. Almario
VIMS Articles
Mangrove wetlands provide ecosystem services for millions of people, most prominently by providing storm protection, food and fodder. Mangrove wetlands are also valuable ecosystems for promoting carbon (C) sequestration and storage. However, loss of mangrove wetlands and these ecosystem services are a global concern, prompting the restoration and creation of mangrove wetlands as a potential solution. Here, we investigate soil surface elevation change, and its components, in created mangrove wetlands over a 25 year developmental gradient. All created mangrove wetlands were exceeding current relative sea-level rise rates (2.6 mm yr(-1)), with surface elevation change of 4.2-11.0 mm yr(-1) compared with …
The Roles Of Resuspension, Diffusion And Biogeochemical Processes On Oxygen Dynamics Offshore Of The Rhone River, France: A Numerical Modeling Study, Julia M. Moriarty, Courtney K. Harris, Katja Fennel, Marjorie A.M. Friedrichs, Kehui Xu, Christophe Rabouille
The Roles Of Resuspension, Diffusion And Biogeochemical Processes On Oxygen Dynamics Offshore Of The Rhone River, France: A Numerical Modeling Study, Julia M. Moriarty, Courtney K. Harris, Katja Fennel, Marjorie A.M. Friedrichs, Kehui Xu, Christophe Rabouille
VIMS Articles
Observations indicate that resuspension and associated fluxes of organic material and porewater between the seabed and overlying water can alter biogeochemical dynamics in some environments, but measuring the role of sediment processes on oxygen and nutrient dynamics is challenging. A modeling approach offers a means of quantifying these fluxes for a range of conditions, but models have typically relied on simplifying assumptions regarding seabed-water-column interactions. Thus, to evaluate the role of resuspension on biogeochemical dynamics, we developed a coupled hydrodynamic, sediment transport, and biogeochemical model (HydroBioSed) within the Regional Ocean Modeling System (ROMS). This coupled model accounts for processes including …
Spatially Integrative Metrics Reveal Hidden Vulnerability Of Microtidal Salt Marshes, Neil K. Ganju, Zafer Defne, Matthew L. Kirwan, Sergio Fagherazzi, Andrea D'Alpaos, Luca Carniello
Spatially Integrative Metrics Reveal Hidden Vulnerability Of Microtidal Salt Marshes, Neil K. Ganju, Zafer Defne, Matthew L. Kirwan, Sergio Fagherazzi, Andrea D'Alpaos, Luca Carniello
VIMS Articles
Salt marshes are valued for their ecosystem services, and their vulnerability is typically assessed through biotic and abiotic measurements at individual points on the landscape. However, lateral erosion can lead to rapid marsh loss as marshes build vertically. Marsh sediment budgets represent a spatially integrated measure of competing constructive and destructive forces: a sediment surplus may result in vertical growth and/or lateral expansion, while a sediment deficit may result in drowning and/or lateral contraction. Here we show that sediment budgets of eight microtidal marsh complexes consistently scale with areal unvegetated/vegetated marsh ratios (UVVR) suggesting these metrics are broadly applicable indicators …
Transport Of Riverine Material From Multiple Rivers In The Chesapeake Bay: Important Control Of Estuarine Circulation On The Material Distribution, Jiabi Du, Jian Shen
Transport Of Riverine Material From Multiple Rivers In The Chesapeake Bay: Important Control Of Estuarine Circulation On The Material Distribution, Jiabi Du, Jian Shen
VIMS Articles
Driven by estuarine circulation, material released from lower Chesapeake Bay tributaries has the potential to be transported to the upper Bay. How far and what fraction of the material from tributaries can be carried to the upper estuary have not been quantitatively investigated. For an estuary system with multiple tributaries, the relative contribution from each tributary can provide valuable information for source assessment and fate prediction for riverine materials and passive moving organisms. We conducted long-term numerical simulations using multiple passive tracers that are independently released in the headwater of five main rivers (i.e., Susquehanna, Potomac, Rappahannock, York, and James …
The Origins Of The Anomalous Warming In The California Coastal Ocean And San Francisco Bay During 2014-2016, Yi Chao, Et Al., Yinglong J. Zhang
The Origins Of The Anomalous Warming In The California Coastal Ocean And San Francisco Bay During 2014-2016, Yi Chao, Et Al., Yinglong J. Zhang
VIMS Articles
During 2014 exceptionally warm water temperatures developed across a wide area off the California coast and within San Francisco Bay (SFB) and persisted into 2016. Observations and numerical model output are used to document this warming and determine its origins. The coastal warming was mostly confined to the upper 100 m of the ocean and was manifested strongly in the two leading modes of upper ocean (0-100 m) temperature variability in the extratropical eastern Pacific. Observations suggest that the coastal warming in 2014 propagated into nearshore regions from the west while later indicating a warming influence that propagated from south …
Late-Summer Biogeochemistry In The Mertz Polynya: East Antarctica, E. H. Shadwick, B. Tilbrook, K. I. Currie
Late-Summer Biogeochemistry In The Mertz Polynya: East Antarctica, E. H. Shadwick, B. Tilbrook, K. I. Currie
VIMS Articles
A marked reconfiguration of the Mertz Polynya following the 2010 calving of the Mertz Glacier Tongue has been associated with a decrease in the size and activity of the polynya. We report observations of the oceanic carbonate (CO2) system in late-summer 2013, the third post-calving summer season. Estimates of seasonal net community production (NCP) based on inorganic carbon deficits and the oxygen-argon ratio indicate that the waters on the shelf to the east of Commonwealth Bay (adjacent to the Mertz Glacier) remain productive compared to pre-calving conditions. The input of residual or excess alkalinity from melting sea ice is found …