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Articles 1 - 30 of 157
Full-Text Articles in Life Sciences
Aquaculture Governance: Five Engagement Arenas For Sustainability Transformation, Darien D. Mizuta, Stefan Partelow
Aquaculture Governance: Five Engagement Arenas For Sustainability Transformation, Darien D. Mizuta, Stefan Partelow
VIMS Articles
A greater focus on governance is needed to facilitate effective and substantive progress toward sustainability transformations in the aquaculture sector. Concerted governance efforts can help move the sector beyond fragmented technical questions associated with intensification and expansion, social and environmental impacts, and toward system-based approaches that address interconnected sustainability issues. Through a review and expert-elicitation process, we identify five engagement arenas to advance a governance agenda for aquaculture sustainability transformation: (1) setting sustainability transformation goals, (2) cross-sectoral linkages, (3) land–water–sea connectivity, (4) knowledge and innovation, and (5) value chains. We then outline the roles different actors and modes of …
A General Pattern Of Trade-Offs Between Ecosystem Resistance And Resilience To Tropical Cyclones, Christopher J. Patrick, John S. Kominoski, (...), Enie Hensel, Marc J. S. Hense, Bradley A. Strickland, (..), A. K. Hardison, Sean Kinard, Et Al
A General Pattern Of Trade-Offs Between Ecosystem Resistance And Resilience To Tropical Cyclones, Christopher J. Patrick, John S. Kominoski, (...), Enie Hensel, Marc J. S. Hense, Bradley A. Strickland, (..), A. K. Hardison, Sean Kinard, Et Al
VIMS Articles
Tropical cyclones drive coastal ecosystem dynamics, and their frequency, intensity, and spatial distribution are pre-dicted to shift with climate change. Patterns of resistance and resilience were synthesized for 4138 ecosystem time series from n = 26 storms occurring between 1985 and 2018 in the Northern Hemisphere to predict how coastal ecosystems will respond to future disturbance regimes. Data were grouped by ecosystems (fresh water, salt water, terrestrial, and wetland) and response categories (biogeochemistry, hydrography, mobile biota, sedentary fauna, and vascular plants). We observed a repeated pattern of trade-offs between resistance and resilience across analyses. These patterns are likely the outcomes …
New Technologies Aid Understanding Of The Factors Affecting Adélie Penguin Foraging, Walker O. Smith Jr., David G. Ainley, Karen J. Heywood, Grant Ballard
New Technologies Aid Understanding Of The Factors Affecting Adélie Penguin Foraging, Walker O. Smith Jr., David G. Ainley, Karen J. Heywood, Grant Ballard
VIMS Articles
The Ross Sea (Figure 1) is home to 33% of the world’s Adélie penguins (Pygoscelis adeliae), as well as substantial numbers of Emperor penguins (Aptenodytes forsteri), Weddell seals (Leptonychotes weddellii), and pelagic birds (Smith et al., 2014). Among these, the Commission for the Conservation of Antarctic Marine Resources (CCAMLR) has designated the Adélie penguin an “indicator species” for monitoring ecosystem structure and function in the newly designated Ross Sea Region Marine Protected Area (RSR-MPA). This penguin, among the best-known seabirds, has been studied for decades at multiple locations with investigations that have delved into …
Processes And Mechanisms Of Coastal Woody-Plant Mortality, Nate G. Mcdowell, Marilyn Ball, Ben Bond-Lamberty, Matthew L. Kirwan, Et Al
Processes And Mechanisms Of Coastal Woody-Plant Mortality, Nate G. Mcdowell, Marilyn Ball, Ben Bond-Lamberty, Matthew L. Kirwan, Et Al
VIMS Articles
Observations of woody plant mortality in coastal ecosystems are globally widespread, but the overarching processes and underlying mechanisms are poorly understood. This knowledge deficiency, combined with rapidly changing water levels, storm surges, atmospheric CO2, and vapor pressure deficit, creates large predictive uncertainty regarding how coastal ecosystems will respond to global change. Here, we synthesize the literature on the mechanisms that underlie coastal woody-plant mortality, with the goal of producing a testable hypothesis framework. The key emergent mechanisms underlying mortality include hypoxic, osmotic, and ionic-driven reductions in whole-plant hydraulic conductance and photosynthesis that ultimately drive the coupled processes of …
Nutrient Function Over Form: Organic And Inorganic Nitrogen Additions Have Similar Effects On Lake Phytoplankton Nutrient Limitation, Sabrina N. Volponi, Heather L. Wander, (...), Brian S. Kim, Et Al
Nutrient Function Over Form: Organic And Inorganic Nitrogen Additions Have Similar Effects On Lake Phytoplankton Nutrient Limitation, Sabrina N. Volponi, Heather L. Wander, (...), Brian S. Kim, Et Al
VIMS Articles
The concentration of dissolved organic nitrogen (DON) is increasing in many northern hemisphere lakes, yet its use by phytoplankton and fate in the environment seldom have been quantified. We conducted 1 week, insitu, microcosm incubations across 25 lakes in northeastern North America to understand how DON, dissolved norganic nitrogen (DIN), and dissolved inorganic phosphorus (P) affected phytoplankton biomass. In addition,we tested whether lakes were limited by single macronutrients (N or P) or colimited by both. Phytoplankton biomass in 80% of lakes responded similarly to DON and DIN additions. Of the lakes where N form produced differential responses, the majority of …
A Deterministic Model For Understanding Nonlinear Viral Dynamics In Oysters, Qubin Qin, Jian Shen, Kimberly S. Reece
A Deterministic Model For Understanding Nonlinear Viral Dynamics In Oysters, Qubin Qin, Jian Shen, Kimberly S. Reece
VIMS Articles
Contamination of oysters with a variety of viruses is one key pathway to trigger outbreaks of massive oyster mortality as well as human illnesses, including gastroenteritis and hepatitis. Much effort has gone into examining the fate of viruses in contaminated oysters, yet the current state of knowledge of nonlinear virus-oyster interactions is not comprehensive because most studies have focused on a limited number of processes under a narrow range of experimental conditions. A framework is needed for describing the complex nonlinear virus-oyster interactions. Here, we introduce a mathematical model that includes key processes for viral dynamics in oysters, such as …
Using Forward And Backward Particle Tracking Approaches To Analyze Impacts Of A Water Intake On Ichthyoplankton Mortality In The Appomattox River, Qubin Qin, Jian Shen, Troy D. Tuckey, Xun Cai, Jilian Xiong
Using Forward And Backward Particle Tracking Approaches To Analyze Impacts Of A Water Intake On Ichthyoplankton Mortality In The Appomattox River, Qubin Qin, Jian Shen, Troy D. Tuckey, Xun Cai, Jilian Xiong
VIMS Articles
Municipal intakes of surface water have various uses, and their impacts on the aquatic environment and ecosystem, such as the impingement and entrainment of ichthyoplankton, are a major concern. A robust assessment of the intake impacts on ichthyoplankton in a system generally requires modeling efforts that can simulate the transport and dispersal pathways of the ichthyoplankton. However, it is challenging to simulate hydrodynamics with a high‐resolution grid at the
scale needed for intake screen sizes in a large system. In this study, a 3D unstructured grid model with a fine resolution grid (<1 >m) was developed to investigate potential impacts …
Modeling Changes In Baleen Whale Seasonal Abundance, Timing Of Migration, And Environmental Variables To Explain The Sudden Rise In Entanglements In California, Kaytlin Ingman, Ellen Hines, Piero L. F. Mazzini, Et Al
Modeling Changes In Baleen Whale Seasonal Abundance, Timing Of Migration, And Environmental Variables To Explain The Sudden Rise In Entanglements In California, Kaytlin Ingman, Ellen Hines, Piero L. F. Mazzini, Et Al
VIMS Articles
We document changes in the number of sightings and timing of humpback (Megaptera novaeangliae), blue (Balaenoptera musculus), and gray (Eschrichtius robustus) whale migratory phases in the vicinity of the Farallon Islands, California. We hypothesized that changes in the timing of migration off central California were driven by local oceanography, regional upwelling, and basin-scale climate conditions. Using 24 years of daily whale counts collected from Southeast Farallon Island, we developed negative binomial regression models to evaluate trends in local whale sightings over time. We then used linear models to assess trends in the timing of …
Asymmetric Root Distributions Reveal Press–Pulse Responses In Retreating Coastal Forests, Tyler C. Messerschmidt, Amy K. Langston, Matthew L. Kirwan
Asymmetric Root Distributions Reveal Press–Pulse Responses In Retreating Coastal Forests, Tyler C. Messerschmidt, Amy K. Langston, Matthew L. Kirwan
VIMS Articles
The impacts of climate change on ecosystems are manifested in how organisms respond to episodic and continuous stressors. The conversion of coastal forests to salt marshes represents a prominent example of ecosystem state change, driven by the continuous stress of sea-level rise (press), and episodic storms (pulse). Here, we measured the rooting dimension and fall direction of 143 windthrown eastern red cedar (Juniperus virginiana) trees in a rapidly retreating coastal forest in Chesapeake Bay (USA). We found that tree roots were distributed asymmetrically away from the leading edge of soil salinization and towards freshwater sources. The length, number, …
Seasonal Resource Pulses And The Foraging Depth Of A Southern Ocean Top Predator, Roxanne S. Beltran, A. Marm Kilpatrick, Greg A. Breed, (...), Walker O. Smith Jr., Et Al
Seasonal Resource Pulses And The Foraging Depth Of A Southern Ocean Top Predator, Roxanne S. Beltran, A. Marm Kilpatrick, Greg A. Breed, (...), Walker O. Smith Jr., Et Al
VIMS Articles
Seasonal resource pulses can have enormous impacts on species interactions. In marine ecosystems, air-breathing predators often drive their prey to deeper waters. However, it is unclear how ephemeral resource pulses such as near-surface phytoplankton blooms alter the vertical trade-off between predation avoidance and resource availability in consumers, and how these changes cascade to the diving behaviour of top predators. We integrated data on Weddell seal diving behaviour, diet stable isotopes, feeding success and mass gain to examine shifts in vertical foraging throughout ice break-out and the resulting phytoplankton bloom each year. We also tested hypotheses about the likely location of …
Bioaccumulation Of Pcbs, Ocps And Pbdes In Marine Mammals From West Antarctica, Mohammed Khairy, Emily Brault, Rebecca Dickhut, Et Al
Bioaccumulation Of Pcbs, Ocps And Pbdes In Marine Mammals From West Antarctica, Mohammed Khairy, Emily Brault, Rebecca Dickhut, Et Al
VIMS Articles
To understand the bioaccumulation and food web dynamics of persistent organic pollutants (POPs) as a function of species, age and sex in Antarctic mammals, blubber samples of 3 killer whales (Type C) and 77 pinnipeds (Weddell, Ross and crabeater seals) were collected from the Southern Ocean, Antarctica. They were analyzed for polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs) and polybrominated diphenyl ethers (PBDEs). ΣDDTs, Σ29PCBs and chlordanes (12 – 4,600, 13 – 1,600, and < 1.5 – 1,700 ng/g lipid, respectively) were the most abundant POPs. Killer whales typically displayed several times greater concentrations of POPs compared to seals, except for PBDEs. PCBs and PBDEs were consistently higher in adult crabeater and Weddell seal males, and in adult female Ross seals than in other sex and age groups reflecting an age accumulation and possible influence of segregated diet, foraging areas, and metabolic transformation rates. POPs concentrations significantly correlated with gene transcription of nuclear receptors involved in detoxification of contaminants and immune relevant cell mediators in the crabeater seals, indicating possible immunotoxic and deleterious health effects. This represents one of the largest studies on POPs in Antarctic marine predators and highlights the complexity of POPs bioaccumulation.
Providential Tides: The Double Low Water Of Narragansett Bay, D. G. Bowers, J. M. Brubaker
Providential Tides: The Double Low Water Of Narragansett Bay, D. G. Bowers, J. M. Brubaker
VIMS Articles
We investigate a mechanism for producing double-lows and double-highs in the semi-diurnal tide by selective amplification of higher harmonics in a resonant gulf. A double low water is observed at Providence, RI, near the head of Narragansett Bay on days when there is a flattening of the low water tidal curve at Newport, at the mouth of the bay. The flattening is caused by an unusually large quarter-diurnal component to the tide at Newport. The quarter diurnal component has the right phase (a maximum close to the time of the minimum in the semi-diurnal tide) to produce a prolonged flattening …
Minimal Effects Of Oyster Aquaculture On Local Water Quality: Examples From Southern Chesapeake Bay, Jessica Turner, M. Lisa Kellogg, Grace M. Massey, Carl Friedrichs
Minimal Effects Of Oyster Aquaculture On Local Water Quality: Examples From Southern Chesapeake Bay, Jessica Turner, M. Lisa Kellogg, Grace M. Massey, Carl Friedrichs
VIMS Articles
As the oyster aquaculture industry grows and becomes incorporated into management practices, it is important to understand its effects on local environments. This study investigated how water quality and hydrodynamics varied among farms as well as inside versus outside the extent of caged grow-out areas located in southern Chesapeake Bay. Current speed and water quality variables (chlorophyll-a fluorescence, turbidity, and dissolved oxygen) were measured along multiple transects within and adjacent to four oyster farms during two seasons. At the scale of individual aquaculture sites, we were able to detect statistically significant differences in current speed and water quality variables between …
Scientific Considerations For Acidification Monitoring In The Us Mid-Atlantic Region, Ka Goldsmith, S Lau, Et Al, Eh Shadwick, Et Al
Scientific Considerations For Acidification Monitoring In The Us Mid-Atlantic Region, Ka Goldsmith, S Lau, Et Al, Eh Shadwick, Et Al
VIMS Articles
Coastal and ocean acidification has the potential to cause significant environmental and societal impacts. Monitoring carbonate chemistry parameters over spatial and temporal scales is challenging, especially with limited resources. A lack of monitoring data can lead to a limited understanding of real-world conditions. Without such data, robust experimental and model design is challenging, and the identification and understanding of episodic acidification events is nearly impossible. We present considerations for resource managers, academia, and industry professionals who are currently developing acidification monitoring programs in the Mid-Atlantic region. We highlight the following considerations for deliberation: 1) leverage existing infrastructure to include multiple …
Bacterial And Archaeal Specific-Predation In The North Atlantic Basin, Lm Seyler, S Tuorto, Lr Mcguinness, Dl Gong, Lj Kerkof
Bacterial And Archaeal Specific-Predation In The North Atlantic Basin, Lm Seyler, S Tuorto, Lr Mcguinness, Dl Gong, Lj Kerkof
VIMS Articles
Stable isotope probing (SIP) was used to track prokaryotic and eukaryotic carbon uptake along a meridional transect (Long. 52°W) in the North Atlantic to assess if 13C-resource partitioning between bacteria and archaea and 13C-labeled eukaryotic predators could be detected. One-liter SIP microcosms were amended with 13C-acetate or 13C-urea and incubated for 48 h. Our data indicated archaea often outcompeted bacteria for 13C-urea while both archaea and bacteria could incorporate 13C-acetate. This 13C label could also be tracked into eukaryotic microbes. The largest number of 13C-labeled eukaryotic OTUs, and the greatest percentage of …
A Data-Driven Modeling Approach For Simulating Algal Blooms In The Tidal Freshwater Of James River In Response To Riverine Nutrient Loading, Jian Shen, Qubin Qin, Ya Wang, Mac Sisson
A Data-Driven Modeling Approach For Simulating Algal Blooms In The Tidal Freshwater Of James River In Response To Riverine Nutrient Loading, Jian Shen, Qubin Qin, Ya Wang, Mac Sisson
VIMS Articles
Algal blooms often occur in the tidal freshwater (TF) of the James River estuary, a tributary of the Chesapeake Bay. The timing of algal blooms correlates highly to a summer low-flow period when residence time is long and nutrients are available. Because of complex interactions between physical transport and algal dynamics, it is challenging to predict interannual variations of bloom correctly using a complex eutrophication model without having ahigh-resolution model gridto resolve complexgeometryand anaccurate estimate of nutrientloading to drive the model. In this study, an approach using long-term observational data (from 1990 to 2013) and the Support vector machine (LS-SVM) …
Advancing Marine Biogeochemical And Ecosystem Reanalyses And Forecasts As Tools For Monitoring And Managing Ecosystem Health, K Fennel, M Gehlen, P Brasseur, Cw Brown, C Ciavatta, G Cossarini, A Crise, Ca Edwards, D Ford, Marjorie A.M. Friedrichs, Et Al
Advancing Marine Biogeochemical And Ecosystem Reanalyses And Forecasts As Tools For Monitoring And Managing Ecosystem Health, K Fennel, M Gehlen, P Brasseur, Cw Brown, C Ciavatta, G Cossarini, A Crise, Ca Edwards, D Ford, Marjorie A.M. Friedrichs, Et Al
VIMS Articles
Ocean ecosystems are subject to a multitude of stressors, including changes in ocean physics and biogeochemistry, and direct anthropogenic influences. Implementation of protective and adaptive measures for ocean ecosystems requires a combination of ocean observations with analysis and prediction tools. These can guide assessments of the current state of ocean ecosystems, elucidate ongoing trends and shifts, and anticipate impacts of climate change and management policies. Analysis and prediction tools are defined here as ocean circulation models that are coupled to biogeochemical or ecological models. The range of potential applications for these systems is broad, ranging from reanalyses for the assessment …
The Effect Of A Small Vegetation Dieback Event On Salt Marsh Sediment Transport, Daniel J. Coleman, Matthew L. Kirwan
The Effect Of A Small Vegetation Dieback Event On Salt Marsh Sediment Transport, Daniel J. Coleman, Matthew L. Kirwan
VIMS Articles
Vegetation is a critical component of the ecogeomorphic feedbacks that allow a salt marsh to build soil and accrete vertically. Vegetation dieback can therefore have detrimental effects on marsh stability, especially under conditions of rising sea levels. Here, we report a variety of sediment transport measurements associated with an unexpected, natural dieback in a rapidly prograding marsh in the Altamaha River Estuary, Georgia. We find that vegetation mortality led to a significant loss in elevation at the dieback site as evidenced by measurements of vertical accretion, erosion, and surface topography compared to vegetated refer- ence areas. Below-ground vegetation mortality led …
Symbiotic Unicellular Cyanobacteria Fix Nitrogen In The Arctic Ocean, K. Harding, K. A. Turk-Kubo, Rachel E. Sipler, M. M. Mills, D. A. Bronk
Symbiotic Unicellular Cyanobacteria Fix Nitrogen In The Arctic Ocean, K. Harding, K. A. Turk-Kubo, Rachel E. Sipler, M. M. Mills, D. A. Bronk
VIMS Articles
Biological dinitrogen (N2) fixation is an important source of nitrogen (N) in low-latitude open oceans. The unusual N2-fixing unicellular cyanobacteria (UCYN-A)/haptophyte symbiosis has been found in an increasing number of unexpected environments, including northern waters of the Danish Straight and Bering and Chukchi Seas. We used nanoscale secondary ion mass spectrometry (nanoSIMS) to measure 15N2 uptake into UCYN-A/haptophyte symbiosis and found that UCYN-A strains identical to low-latitude strains are fixing N2 in the Bering and Chukchi Seas, at rates comparable to subtropical waters. These results show definitively that cyanobacterial N2 fixation is not constrained to subtropical waters, challenging paradigms and …
The Contribution Of Local And Transport Processes To Phytoplankton Biomass Variability Over Different Timescales In The Upper James River, Virginia, Qubin Quin, Jian Shen
The Contribution Of Local And Transport Processes To Phytoplankton Biomass Variability Over Different Timescales In The Upper James River, Virginia, Qubin Quin, Jian Shen
VIMS Articles
Although both local processes (photosynthesis, respiration, grazing, and settling), and transport processes (advective transport and diffusive transport) significantly affect local phytoplankton dynamics, it is difficult to separate their contributions and to investigate the relative importance of each process to the local variability of phytoplankton biomass over different timescales. A method of using the transport rate is introduced to quantify the contribution of transport processes. By combining the time-varying transport rate and high-frequency observed chlorophyll a data, we can explicitly examine the impact of local and transport processes on phytoplankton biomass over a range of timescales from hourly to annually. For …
Millennial Soil Retention Of Terrestrial Organic Matter Deposited In The Bengal Fan, Kl French, Christopher J. Hein, N Haghipour, L Wacker, Hr Kudrass
Millennial Soil Retention Of Terrestrial Organic Matter Deposited In The Bengal Fan, Kl French, Christopher J. Hein, N Haghipour, L Wacker, Hr Kudrass
VIMS Articles
The abundance of organic carbon (OC) in vegetation and soils (similar to 2,600 PgC) compared to carbon in the atmosphere (similar to 830 PgC) highlights the importance of terrestrial OC in global carbon budgets. The residence time of OC in continental reservoirs, which sets the rates of carbon exchange between land and atmosphere, represents a key uncertainty in global carbon cycle dynamics. Retention of terrestrial OC can also distort bulk OC- and biomarker-based paleorecords, yet continental storage timescales remain poorly quantified. Using "bomb" radiocarbon (C-14) from thermonuclear weapons testing as a tracer, we model leaf-wax fatty acid and bulk OC …
Predicting Marsh Vulnerability To Sea-Level Rise Using Holocene Relative Sea-Level Data, Bp Horton, I Shennan, Sl Bradley, N Cahill, Matthew L. Kirwan, Re Kopp, Ta Shaw
Predicting Marsh Vulnerability To Sea-Level Rise Using Holocene Relative Sea-Level Data, Bp Horton, I Shennan, Sl Bradley, N Cahill, Matthew L. Kirwan, Re Kopp, Ta Shaw
VIMS Articles
Tidal marshes rank among Earth's vulnerable ecosystems, which will retreat if future rates of relative sea-level rise (RSLR) exceed marshes' ability to accrete vertically. Here, we assess the limits to marsh vulnerability by analyzing >780 Holocene reconstructions of tidal marsh evolution in Great Britain. These reconstructions include both transgressive (tidal marsh retreat) and regressive (tidal marsh expansion) contacts. The probability of a marsh retreat was conditional upon Holocene rates of RSLR, which varied between -7.7 and 15.2 mm/yr. Holocene records indicate that marshes are nine times more likely to retreat than expand when RSLR rates are >= 7.1 mm/yr. Coupling …
Numerical Model Of Geochronological Tracers For Deposition And Reworking Applied To The Mississippi Subaqueous Delta, Jj Birchler, Courtney K. Harris, Ta Kniskern, Cr Sherwood
Numerical Model Of Geochronological Tracers For Deposition And Reworking Applied To The Mississippi Subaqueous Delta, Jj Birchler, Courtney K. Harris, Ta Kniskern, Cr Sherwood
VIMS Articles
Measurements of naturally occurring, short-lived radioisotopes from sediment cores on the Mississippi subaqueous delta have been used to infer event bed characteristics such as depositional thicknesses and accumulation rates. Specifically, the presence of Beryllium-7 (Be-7) indicates recent riverine-derived terrestrial sediment deposition; while Thorium-234 (Th-234) provides evidence of recent suspension in marine waters. Sediment transport models typically represent coastal flood and storm deposition via estimated grain size patterns and deposit thicknesses, however, and do not directly calculate radioisotope activities and profiles, which leads to a disconnect between the numerical model and field observations. Here, observed radioisotopic profiles from the Mississippi subaqueous …
Cross-Scale Baroclinic Simulation Of The Effect Of Channel Dredging In An Estuarine Setting, Fei Ye, Harry V. Wang, H Huang, Zg Wang, Z Liu, X Li
Cross-Scale Baroclinic Simulation Of The Effect Of Channel Dredging In An Estuarine Setting, Fei Ye, Harry V. Wang, H Huang, Zg Wang, Z Liu, X Li
VIMS Articles
Holistic simulation approaches are often required to assess human impacts on a river-estuary-coastal system, due to the intrinsically linked processes of contrasting spatial scales. In this paper, a Semi-implicit Cross-scale Hydroscience Integrated System Model (SCHISM) is applied in quantifying the impact of a proposed hydraulic engineering project on the estuarine hydrodynamics. The project involves channel dredging and land expansion that traverse several spatial scales on an ocean-estuary-river-tributary axis. SCHISM is suitable for this undertaking due to its flexible horizontal and vertical grid design and, more importantly, its efficient high-order implicit schemes applied in both the momentum and transport calculations. These …
Discerning Autotrophy, Mixotrophy And Heterotrophyin Marine Tack Archaea From The North Atlantic, L M. Seyler, L. R. Mcguinness, J. A. Gilbert, J. F. Biddle, Donglai Gong, L. J. Kerkhof
Discerning Autotrophy, Mixotrophy And Heterotrophyin Marine Tack Archaea From The North Atlantic, L M. Seyler, L. R. Mcguinness, J. A. Gilbert, J. F. Biddle, Donglai Gong, L. J. Kerkhof
VIMS Articles
DNA stable isotope probing (SIP) was used to track the uptake of organic and inorganic carbon sources for TACK archaea(Thaumarchaeota/Aigarchaeota/Crenarchaeota/Korarchaeota) on a cruise of opportunity in the North Atlantic. Due to water limitations, duplicate samples from the deep photic (60–115 m), the mesopelagic zones (local oxygen minimum; 215–835 m)and the bathypelagic zone (2085–2835 m) were amended with various combinations of12C- or13C-acetate/urea/bicarbonate to assess cellular carbon acquisition. The SIP results indicated the majority of TACK archaeal operational taxonomic units(OTUs) incorporated13C from acetate and/or urea into newly synthesized DNA within 48 h. A small fraction (16%) of the OTUs, often representing the …
Accuracy And Precision Of Tidal Wetland Soil Carbon Mapping In The Conterminous United States, Jr Holmquist, L Windham-Myers, N Bliss, S Crooks, Jt Morris, W. G. Reay, Et Al.
Accuracy And Precision Of Tidal Wetland Soil Carbon Mapping In The Conterminous United States, Jr Holmquist, L Windham-Myers, N Bliss, S Crooks, Jt Morris, W. G. Reay, Et Al.
VIMS Articles
Tidal wetlands produce long-term soil organic carbon (C) stocks. Thus for carbon accounting purposes, we need accurate and precise information on the magnitude and spatial distribution of those stocks. We assembled and analyzed an unprecedented soil core dataset, and tested three strategies for mapping carbon stocks: applying the average value from the synthesis to mapped tidal wetlands, applying models fit using empirical data and applied using soil, vegetation and salinity maps, and relying on independently generated soil carbon maps. Soil carbon stocks were far lower on average and varied less spatially and with depth than stocks calculated from available soils …
Spatial Distribution And Morphological Responses To Predation In The Salt Marsh Periwinkle, Aj Rietl, Mg Sorrentino, Bj Roberts
Spatial Distribution And Morphological Responses To Predation In The Salt Marsh Periwinkle, Aj Rietl, Mg Sorrentino, Bj Roberts
VIMS Articles
The salt marsh periwinkle (Littoraria irrorata) is a common and often abundant mollusk in marshes of the Gulf and Atlantic coasts of the United States. Several studies have focused on the effects of periwinkles on Spartina alterniflora production and the effects of oil on periwinkle survivability, yet the general ecology of the snail has been underreported. In this study, we measured spatial distributions, biomass, shell repair frequency, and a suite of morphological characteristics of L. irrorata at three sites in each of five regions spanning the southeastern Louisiana Coast between the Atchafalaya and Mississippi rivers. Sampling was conducted along 50 …
Time Trends Of Polybrominated Diphenyl Ethers (Pbdes) In Antarctic Biota, E Markham, Ek Brault, M Khairy, Ar Robuck, Me Goebel, Mg Cantwell, Rm Dickhut, R Lohmann
Time Trends Of Polybrominated Diphenyl Ethers (Pbdes) In Antarctic Biota, E Markham, Ek Brault, M Khairy, Ar Robuck, Me Goebel, Mg Cantwell, Rm Dickhut, R Lohmann
VIMS Articles
Polybrominated diphenyl ethers (PBDEs) are "emerged" contaminants that were produced and used as flame retardants in numerous consumer and industrial applications for decades until banned. They remain ubiquitously present in the environment today. Here, a unique set of >200 biotic samples from the Antarctic was analyzed for PBDEs, including phytoplankton, krill, fish, and fur seal milk, spanning several sampling seasons over 14 years. PBDE-47 and -99 were the dominant congeners determined in all samples, constituting > 60% of total PBDEs. A temporal trend was observed for Sigma 7PBDE concentrations in fur seal milk, where concentrations significantly increased (R-2 = 0.57, p < 0.05) over time (2000-2014). Results for krill and phytoplankton also suggested increasing PBDE concentrations over time. Trends of PBDEs in fur seal milk of individual seals sampled 1 or more years apart showed no clear temporal trends. Overall, there was no indication of PBDEs decreasing in Antarctic biota yet, whereas numerous studies have reported decreasing trends in the northern hemisphere. Similar PBDE concentrations in perinatal versus nonperinatal milk implied the importance of local PBDE sources for bioaccumulation. These results indicate the need for continued assessment of contaminant trends, such as PBDEs, and their replacements, in Antarctica.
Cohesive And Mixed Sediment In The Regional Ocean Modeling System (Roms V3.6) Implemented In The Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System (Coawst R1234), Cr Sherwood, Al Aretxabaleta, Courtney K. Harris, Jp Rinehimer, R Verney, B Ferre
Cohesive And Mixed Sediment In The Regional Ocean Modeling System (Roms V3.6) Implemented In The Coupled Ocean-Atmosphere-Wave-Sediment Transport Modeling System (Coawst R1234), Cr Sherwood, Al Aretxabaleta, Courtney K. Harris, Jp Rinehimer, R Verney, B Ferre
VIMS Articles
We describe and demonstrate algorithms for treating cohesive and mixed sediment that have been added to the Regional Ocean Modeling System (ROMS version 3.6), as implemented in the Coupled Ocean-Atmosphere-Wave- Sediment Transport Modeling System (COAWST Subversion repository revision 1234). These include the following: floc dynamics (aggregation and disaggregation in the water column); changes in floc characteristics in the seabed; erosion and deposition of cohesive and mixed (combination of cohesive and non-cohesive) sediment; and biodiffusive mixing of bed sediment. These routines supplement existing noncohesive sediment modules, thereby increasing our ability to model fine-grained and mixed-sediment environments. Additionally, we describe changes to …
The Competing Impacts Of Climate Change And Nutrient Reductions On Dissolved Oxygen In Chesapeake Bay, Id Irby, Marjorie A.M. Friedrichs, F Da, Ke Hinson
The Competing Impacts Of Climate Change And Nutrient Reductions On Dissolved Oxygen In Chesapeake Bay, Id Irby, Marjorie A.M. Friedrichs, F Da, Ke Hinson
VIMS Articles
The Chesapeake Bay region is projected to experience changes in temperature, sea level, and precipitation as a result of climate change. This research uses an estuarine-watershed hydrodynamic-biogeochemical modeling system along with projected mid-21st-century changes in temperature, freshwater flow, and sea level rise to explore the impact climate change may have on future Chesapeake Bay dissolved-oxygen (DO) concentrations and the potential success of nutrient reductions in attaining mandated estuarine water quality improvements. Results indicate that warming bay waters will decrease oxygen solubility year-round, while also increasing oxygen utilization via respiration and remineralization, primarily impacting bottom oxygen in the spring. Rising sea …