Oceanography Commons^™

Estimating Carbon Flux From Optically Recording Total Particle Volume At Depths Below The Primary Pycnocline, Alexander B. Bochdansky, Robert B. Dunbar, Dennis A. Hansell, Gerhard J. Herndl

OES Faculty Publications

Optical instruments can rapidly determine numbers and characteristics of water column particles with high sensitivity. Here we show the usefulness of optically assessed total particle volume below the main pycnocline to estimate carbon export in two systems: the open subarctic North Atlantic and the Ross Sea, Antarctica. Both regions exhibit seasonally high phytoplankton production and efficient export (i.e., a strong biological pump). Total particle volumes in the mesopelagic (200-300 m) were significantly correlated with those in the overlying surface mixed layer (50-60 m), indicating that most particles at depth reflect export from the surface. This connectivity, however, is modulated by …

Defining Boat Wake Impacts On Shoreline Stability Toward Management And Policy Solutions, Donna Marie Bilkovic, Molly M. Mitchell, Jennifer Davis, Julie Herman, Elizabeth Andrews, Angela King, Pamela Mason, Navid Tahvildari, Jana Davis, Rachel L. Dixon

Civil & Environmental Engineering Faculty Publications

Coastal economies are often supported by activities that rely on commercial or recreational vessels to move people or goods, such as shipping, transportation, cruising, and fishing. Unintentionally, frequent or intense vessel traffic can contribute to erosion of coastlines; this can be particularly evident in sheltered systems where shoreline erosion should be minimal in the absence of boat waves. We reviewed the state of the science of known effects of boat waves on shoreline stability, examined data on erosion, turbidity, and shoreline armoring patterns for evidence of a response to boat waves in Chesapeake Bay, and reviewed existing management and policy …

Temporal And Spatial Scales Of Correlation In Marine Phytoplankton Communities, A. M. Kuhn, S. Dutkiewicz, O. Jahn, Sophie Clayton, T. A. Rynearson, M. R. Mazloff, A. D. Barton

OES Faculty Publications

Ocean circulation shapes marine phytoplankton communities by setting environmental conditions and dispersing organisms. In addition, processes acting on the water column (e.g., heat fluxes and mixing) affect the community structure by modulating environmental variables that determine in situ growth and loss rates. Understanding the scales over which phytoplankton communities vary in time and space is key to elucidate the relative contributions of local processes and ocean circulation on phytoplankton distributions. Using a global ocean ecosystem model, we quantify temporal and spatial correlation scales for phytoplankton phenotypes with diverse functional traits and cell sizes. Through this analysis, we address these questions: …

Increased Fluvial Runoff Terminated Inorganic Aragonite Precipitation On The Northwest Shelf Of Australia During The Early Holocene, Maximilian Hallenberger, Lars Reuning, Stephen J. Gallagher, Stefan Back, Takeshige Ishiwa, Beth A. Christensen, Kara Bogus

School of Earth & Environment Departmental Research

Inorganic precipitation of aragonite is a common process within tropical carbonate environments. Across the Northwest Shelf of Australia (NWS) such precipitates were abundant in the late Pleistocene, whereas present-day sedimentation is dominated by calcitic bioclasts. This study presents sedimentological and geochemical analyses of core data retrieved from the upper 13 meters of IODP Site U1461 that provide a high-resolution sedimentary record of the last ~15 thousand years. Sediments that formed from 15 to 10.1 ka BP are aragonitic and characterised by small needles (<5 >µm) and ooids. XRF elemental proxy data indicate that these sediments developed under arid conditions in …

Growth Phase Proteomics Of The Heterotrophic Marine Bacterium Ruegeria Pomeroyi, Dasha Krayushkina, Emma Timmins-Schiffman, Jessica Faux, Damon H. May, Michael Riffle, H. Rodger Harvey, Brook L. Nunn

OES Faculty Publications

The heterotrophic marine bacterium, Ruegeria pomeroyi, was experimentally cultured under environmentally realistic carbon conditions and with a tracer-level addition of ¹³C-labeled leucine to track bacterial protein biosynthesis through growth phases. A combination of methods allowed observation of real-time bacterial protein production to understand metabolic priorities through the different growth phases. Over 2000 proteins were identified in each experimental culture from exponential and stationary growth phases. Within two hours of the ¹³C-labeled leucine addition, R. pomeroyi significantly assimilated the newly encountered substrate into new proteins. This dataset provides a fundamental baseline for understanding growth phase differences in molecular …

The Role Of Eddies And Topography In The Export Of Shelf Waters From The West Antarctic Peninsula Shelf, J. Alexander Brearler, Caelos Moffat, Hugh J. Venables, Michael P. Meredith, Michael S. Dinniman

CCPO Publications

Oceanic heat strongly influences the glaciers and ice shelves along West Antarctica. Prior studies show that the subsurface onshore heat flux from the Southern Ocean on the shelf occurs through deep, glacially carved channels. The mechanisms enabling the export of colder shelf waters to the open ocean, however, have not been determined. Here, we use ocean glider measurements collected near the mouth of Marguerite Trough (MT), west Antarctic Peninsula, to reveal shelf‐modified cold waters on the slope over a deep (2,700 m) offshore topographic bank. The shelf hydrographic sections show subsurface cold features (θ

Editorial-The 9th International Workshop On Modeling The Ocean (Iwmo 2017) In Seoul, Korea, July 3–6, 2017, Lie-Yauw Oey, Yign Noh, Jarle Berntsen, Sung Yong Kim, Humio Mitsudera, Tal Ezer

CCPO Publications

(First paragraph) The 9th International Workshop on Modeling the Ocean (IWMO 2017) was held in the modern campus of Yonsei University, Seoul, Korea, from July 3–6 2017. The workshop was attended by about 80 participants from countries all around the world, many of whom were young and earliercareer scientists: students and postdocs. Papers were presented covering a broad range oftopics on field observations, analyses, and modeling: wave and air-sea interaction dynamics, climate variability, basin-scale processes and coastal oceanography, sea-ice dynamics, sediment transport, tropical cyclones, biogeochemical-physical coupling, boundary currents, sea-level rise, extreme events, ocean prediction and others. We were pleased to …

Gulf Of Mexico Hypoxia: Past, Present, And Future, Nancy N. Rabalais, R. Eugene Turner

Faculty Publications

One of the largest human-caused areas of bottom-water oxygen deficiency in the coastal ocean is on the northern Gulf of Mexico continental shelf adjacent to the Mississippi River, which discharges nitrogen and phosphorus loads into its surface waters. The beginnings of seasonal hypoxia (≤2 mg l−1 dissolved oxygen) in this area was in the 1950s with an acceleration in the worsening of severity during the 1970s. Currently, the bottom area of hypoxic areas can approach 23,000 km2, and the volume, 140 km3. Ecosystems, people, and economies are now at risk within the Mississippi River watershed and in the northern Gulf …

A New 30 Meter Resolution Global Shoreline Vector And Associated Global Islands Database For The Development Of Standardized Ecological Coastal Units, Roger Sayre, Suzanne Noble, Sharon Hamann, Rebecca Smith, Dawn Wright, Sean Breyer, Kevin Butler, Keith Van Graafeiland, Charlie Frye, Deniz Karagulle, Dabney Hopkins, Drew Stephens, Kevin Kelly, Zeenatul Basher, Devon Burton, Jill Cress, Karina Atkins, D. Paco Van Sistine, Beverly Friesen, Revecca Allee, Tom Allen, Peter Aniello, Irawan Asaad, Mark John Costello, Kathy Goodin, Peter Harris, Maria Kavanaugh, Helen Lillis, Elonora Manca, Frank Muller-Karger, Bjorn Nyberg, Rost Parsons, Jusrin Saarinen, Jack Steiner, Adam Reed

Political Science & Geography Faculty Publications

A new 30-m spatial resolution global shoreline vector (GSV) was developed from annual composites of 2014 Landsat satellite imagery. The semi-automated classification of the imagery was accomplished by manual selection of training points representing water and non-water classes along the entire global coastline. Polygon topology was applied to the GSV, resulting in a new characterisation of the number and size of global islands. Three size classes of islands were mapped: continental mainlands (5), islands greater than 1 km² (21,818), and islands smaller than 1 km² (318,868). The GSV represents the shore zone land and water interface boundary, and …

Closing The Oxygen Mass Balance In Shallow Coastal Ecosystems, Matthew H. Long, Jennie E. Rheuban, Daniel C. Mccorkle, David J. Burdige, Richard C. Zimmerman

OES Faculty Publications

The oxygen concentration in marine ecosystems is influenced by production and consumption in the water column and fluxes across both the atmosphere-water and benthic-water boundaries. Each of these fluxes has the potential to be significant in shallow ecosystems due to high fluxes and low water volumes. This study evaluated the contributions of these three fluxes to the oxygen budget in two contrasting ecosystems, a Zostera marina (eelgrass) meadow in Virginia, U.S.A., and a coral reef in Bermuda. Benthic oxygen fluxes were evaluated by eddy covariance. Water column oxygen production and consumption were measured using an automated water incubation system. Atmosphere-water …

Seaflow Data V1, High-Resolution Abundance, Size And Biomass Of Small Phytoplankton In The North Pacific, François Ribalet, Chris Berthiaume, Annette Hynes, Jarred Swalwell, Michael Carlson, Sophie Clayton, Gwenn Hennon, Camille Poirier, Eric Shimabukuro, Angelicque White, E. Virginia Armhurst

OES Faculty Publications

SeaFlow is an underway flow cytometer that provides continuous shipboard observations of the abundance and optical properties of small phytoplankton (μm in equivalent spherical diameter, ESD). Here we present data sets consisting of SeaFlow-based cell abundance, forward light scatter, and pigment fluorescence of individual cells, as well as derived estimates of ESD and cellular carbon content of picophytoplankton, which includes the cyanobacteria Prochlorococcus, Synechococcus and small-sized Crocosphaera (μm ESD), and picophytoplankton and nanophytoplankton (2–5 μm ESD). Data were collected in surface waters (≈5 m depth) from 27 oceanographic cruises carried out in the Northeast Pacific Ocean between 2010 and 2018. …

The Importance Of Antarctic Krill In Biogeochemical Cycles, El Cavan, A Belcher, Sl Hill, S Kawaguchi, S Mccormack, B Meyer, S Nicol, K Schmidt, Deborah K. Steinberg, Ga Tarling, Pw Boyd

VIMS Articles

Antarctic krill (Euphausia superba) are swarming, oceanic crustaceans, up to two inches long, and best known as prey for whales and penguins – but they have another important role. With their large size, high biomass and daily vertical migrations they transport and transform essential nutrients, stimulate primary productivity and influence the carbon sink. Antarctic krill are also fished by the Southern Ocean’s largest fishery. Yet how krill fishing impacts nutrient fertilisation and the carbon sink in the Southern Ocean is poorly understood. Our synthesis shows fishery management should consider the influential biogeochemical role of both adult and larval …

Odu's Blue Line Project To Illustrate The Future Of Flooding In Norfolk, News @ Odu

News Items

No abstract provided.

Age And Growth Of Hardhead Catfish And Gafftopsail Catfish In Coastal Louisiana, Usa, Shane Flinn, Stephen Midway

Faculty Publications

The Hardhead Catfish Ariopsis felis and Gafftopsail Catfish Bagre marinus are marine catfishes that have low recreational and commercial landings in U.S. waters, although they are among the most abundant species in coastal waters of the Gulf of Mexico. Few biological studies exist on marine catfishes, with most studies focusing on their unique reproductive biology. This study evaluated weight-length relationships for Gafftopsail Catfish (n = 264) and Hardhead Catfish (n = 823) sampled from across coastal Louisiana, USA, during 2016-2018; subsamples (93 and 266, respectively) were aged using lapilli for age and growth analyses. Hardhead Catfish showed a small but …

Improving Thorium-230 Determination In Marine Sediment, Katherine Mateos

Independent Study Project (ISP) Collection

Our oceans are intimately related to the climate of our planet. Paleoceanographic approaches aim to study oceans through geologic time to improve models of future climate. Radioisotopes provide us with chemical tracers that help us understand change through time. The uraniumseries decay chain contains thorium-230, a decay product of uranium-234. This isotope is useful to paleoceanographers in its disequilibrium to its parent isotope and in determining the flux of sediment falling to the ocean floor. In order to use 230Th to study oceans, we must be able to accurately measure the amount of thorium in sediment samples. Thorium is found …

Designing An Accessible Wave Energy Conversion Device For Powering Ocean Sensors, Sophie Coppieters ‘T Wallant

Independent Study Project (ISP) Collection

Currently, less than 5% of our oceans are comprehensively monitored and much more ocean data is needed to facilitate understanding of ocean physics, carbon cycling, and ocean ecosystems. Today, most autonomous ocean sensors are powered by primary battery, which have both limited capacity and lifetime. The goal of this research is to design a small, accessible renewable wave energy device to power autonomous free-floating ocean sensors. By designing a cheap, accessible, and simple wave energy converter, this work hopes to make ocean sensor deployment easier and cheaper for researchers, increase the lifetime of autonomous ocean sensors, and reduce the reliance …

The Influence Of Location, Positioning, And Seasonality On Feeding Behavior Of The Sydney Oyster (Saccostrea Glomerata) In New South Wales, Australia, Nathaniel Hess

Independent Study Project (ISP) Collection

Oysters are hard shelled bivalves that aggregate over time to create structures in estuarine systems, known as oyster reefs. These reefs are important for the promotion of estuarine biodiversity by supporting many species of fish, invertebrates, and plants. They also act as a key contributor to water health by using active suspension feeding mechanisms and selective feeding to remove nutrients and water borne pollutants from estuarine systems. They have been touted as possible bio-remediators. They also effect rates of sedimentation in estuaries.

Oyster reefs have historically been threatened by anthropogenic influences such as overharvesting, destructive fishing practices, water pollution, CO2 …

Impacts Of Sea Level Rise On Hypoxia In The Chesapeake Bay: A Model Intercomparison, Pierre St-Laurent, Marjorie A.M. Friedrichs, Ming Li, Wenfei Ni

Reports

Over recent years a number of studies have examined the effects of sea level rise (SLR) on hypoxia in Chesapeake Bay. However, variations in the methodology, the years considered, and the metrics reported made comparisons between these studies difficult. To clarify the effects of SLR on the Bay’s hypoxia, we present an intercomparison between four numerical models following a common methodology. The models share the riverine fluxes, baseline period (1991–1995), and consider the same three scenarios of SLR: an increase in sea level of 0.17m, 0.50m, and 1.00m (representative of years 2025, 2050 and 2100, respectively). SLR is the sole …

James River Water Quality Model Refinement And Scenario Simulations, Jian Shen, Qubin Qin

Reports

This project was part of the Virginia Department of Environmental Quality’s (DEQ) study to evaluate the protectiveness of chlorophyll criteria and consider potential criteria revisions, along with implications for the James River portion of the Chesapeake Bay TMDL.

Coastal Stream Salinity And Its Impacts On Pemba Agriculture, Sara Mccormack

Independent Study Project (ISP) Collection

The extent of saltwater inundation of coastal streams was assessed on Pemba Island near agricultural areas in northeastern and northwestern regions of the island. Conductivity and pH were measured from water samples collected at various distances along the stream to determine the extent of salinity at different points in the tidal cycle. This salinity data, as well as the context of recent weather events, runoff, and geological characteristics of the region were used to determine the primary factors that influence changes in surface water salinity. The primary factor that influences surface water salinity was determined to be changes in stream …

Pacts 1.0: A Crowdsourced Reporting Standard For Paleoclimate Data, D. Khider, J. Emile-Geay, N. P. Mckay, Y. Gil, D. Garijo, V. Ratnakar, M. Alonso-Garcia, S. Bertrand, O. Bothe, P. Brewer, A. Bunn, M. Chevalier, L. Comas-Bru, J. Hertzberg, Y. Zhou

OES Faculty Publications

The progress of science is tied to the standardization of measurements, instruments, and data. This is especially true in the Big Data age, where analyzing large data volumes critically hinges on the data being standardized. Accordingly, the lack of community-sanctioned data standards in paleoclimatology has largely precluded the benefits of Big Data advances in the field. Building upon recent efforts to standardize the format and terminology of paleoclimate data, this article describes the Paleoclimate Community reporTing Standard (PaCTS), a crowdsourced reporting standard for such data. PaCTS captures which information should be included when reporting paleoclimate data, with the goal of …

36 Years After The Species' Mass-Mortality: Diadema Antillarum Test Sizes, Population Densities, And Substrate Preferences In Three Guna Yala Reefs Near Wichub Wala Island, Bimini Horstmann

Independent Study Project (ISP) Collection

In January 1983, a waterborne pathogen beginning near the Atlantic Panama Canal entrance caused history's largest recorded marine animal die-off, wiping out 95-99% of Diadema antillarum populations throughout the Caribbean. D. antillarum, the long-spined sea urchin, is a keystone herbivore in coral reefs and its decreased densities have caused many reefs to suffer macroalgal phase shifts. Modest recovery of this species has been documented in some Caribbean locations, but reefs in Guna Yala, Panama continued to experience population decline. This study investigates density, test size, and substrate preferences of D. antillarum in three shallow coral reef areas to update the …

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 …

The Floodwater Depth Estimation Tool (Fwdet V2.0) For Improved Remote Sensing Analysis Of Coastal Flooding, S Cohen, A Raney, D Munasinghe, Jon Derek Loftis, Et Al

VIMS Articles

Remote sensing analysis is routinely used to map flooding extent either retrospectively or in near-real time. For flood emergency response, remote-sensing-based flood mapping is highly valuable as it can offer continued observational information about the flood extent over large geographical domains. Information about the floodwater depth across the inundated domain is important for damage assessment, rescue, and prioritizing of relief resource allocation, but cannot be readily estimated from remote sensing analysis. The Floodwater Depth Estimation Tool (FwDET) was developed to augment remote sensing analysis by calculating water depth based solely on an inundation map with an associated digital elevation model …

Tidal Variation In Cohesive Sediment Distribution And Sensitivity To Flocculation And Bed Consolidation In An Idealized, Partially Mixed Estuary, Danielle R.N. Tarpley, Courtney K. Harris, Carl Friedrichs, Christopher T. Sherwood

VIMS Articles

Particle settling velocity and erodibility are key factors that govern the transport of sediment through coastal environments including estuaries. These are difficult to parameterize in models that represent mud, whose properties can change in response to many factors, including tidally varying suspended sediment concentration (SSC) and shear stress. Using the COAWST (Coupled Ocean-Atmosphere-Wave-Sediment Transport) model framework, we implemented bed consolidation, sediment-induced stratification, and flocculation formulations within an idealized two-dimensional domain that represented the longitudinal dimension of a micro-tidal, muddy, partially mixed estuary. Within the Estuarine Turbidity Maximum (ETM), SSC and median floc diameter varied by a factor of four over …

The Tensile Root Strength Of Spartina Patens Varies With Soil Texture And Atrazine Concentration, Lauris O. Hollis, R. Eugene Turner

Faculty Publications

The widely used agricultural herbicide atrazine enters wetlands and may potentially affect wetland plants that provide critical reinforcement of soil strength and contribute to ecosystem stability in ways that may vary among soil types. We conducted greenhouse experiments using four levels of atrazine doses and three different soil textures to test for differences between control and experimental treatments and interactive effects of soil texture and atrazine exposure by using the tensile root strength of the coastal wetland emergent macrophyte Spartina patens as the response variable. The tensile root strength of S. patens was not affected after 50days of atrazine exposure …

Drivers And Impacts Of Water Level Fluctuations In The Mississippi River Delta: Implications For Delta Restoration, Matthew Hiatt, John W. Day, Robert V. Rohli, John Andrew Nyman

Faculty Publications

This review synthesizes the knowledge regarding the environmental forces affecting water level variability in the coastal waters of the Mississippi River delta and relates these fluctuations to planned river diversions. Water level fluctuations vary significantly across temporal and spatial scales, and are subject to influences from river flow, tides, vegetation, atmospheric forcing, climate change, and anthropogenic activities. Human impacts have strongly affected water level variability in the Mississippi River delta and other deltas worldwide. Collectively, the research reviewed in this article is important for enhancing environmental, economic, and social resilience and sustainability by assessing, mitigating, and adapting to geophysical changes …

Sea Surface Roughness Observed By High Resolution Radar, Atsushi G. Fujimura, Susanne Lehner, Alexander Soloviev, Xiaofeng Li

Marine & Environmental Sciences Faculty Articles

Changes in the sea surface roughness are usually associated with a change in the sea surface wind field. This interaction has been exploited to measure the sea surface wind speed by scatterometry. A number of features on the sea surface associated with changes in roughness can be observed by synthetic aperture radar (SAR) because of the change in Bragg backscatter of the radar signal by damping of the resonant ocean capillary waves. With various radar frequencies, resolutions, and modes of polarization, sea surface features have been analyzed in numerous campaigns, bringing various datasets together, thus allowing for new insights in …

The Effects Of Oil On Blue Crab And Periwinkle Snail Interactions: A Mesocosm Study, Elizabeth M. Robinson, Nancy N. Rabalais

Faculty Publications

We examined the sub-lethal effect of Macondo oil from the Deepwater Horizon oil spill on predator-prey interactions using blue crabs (Callinectes sapidus) and periwinkle snails (Littoraria irrorata). A 2 x 2 factorial mesocosm design determined the effect of oil (no oil vs. oil) and blue crabs (no blue crab predator vs. one blue crab predator) on periwinkle snail climbing and survival. Sixteen mesocosm tanks were used in the experiment, which were replicated three times. Each tank contained water, sand, and Spartina marsh stems. The sixteen tanks were divided between two, temperature-controlled chambers to separate oil treatments (no oil vs. oil). …

It’S About Time: A Synthesis Of Changing Phenology In The Gulf Of Maine Ecosystem, Md Staudinger, Ke Mills, Et Al, David S. Johnson, Et Al

VIMS Articles

The timing of recurring biological and seasonal environmental events is changing on a global scale relative to temperature and other climate drivers. This study considers the Gulf of Maine ecosystem, a region of high social and ecological importance in the Northwest Atlantic Ocean and synthesizes current knowledge of (a) key seasonal processes, patterns, and events; (b) direct evidence for shifts in timing; (c) implications of phenological responses for linked ecological-human systems; and (d) potential phenology-focused adaptation strategies and actions. Twenty studies demonstrated shifts in timing of regional marine organisms and seasonal environmental events. The most common response was earlier timing, …