Oceanography and Atmospheric Sciences and Meteorology Commons^™

Environmental Controls On Dissolved Carbon Export And River Geochemistry - A Case Study In The Mississippi-Atchafalaya System, Jeremy Reiman

LSU Master's Theses

Rivers serve as an important medium for the exchange of elements between land, ocean, and atmosphere. This thesis consists of three interconnected studies with the overarching goal of analyzing the environmental factors influencing dissolved carbon dynamics and river geochemistry in large rivers. These studies utilized river water samples and in-stream measurements collected from the Mississippi and Atchafalaya Rivers at hourly to monthly intervals between 2013 to 2018, along with ambient river and meteorological data downloaded from public-access databases. Results indicate substantially higher dissolved organic carbon concentrations (DOC, 611 ±181 µmol L^-1) but lower concentrations of dissolved inorganic carbon …

Weather And Climate Summary And Forecast: March 2019 Report, Gregory V. Jones

Linfield University Wine Studies Reports

This report provides a summary of the weather and climate forecast for March 2019. It includes forecast information specific to the Pacific Northwest and the western United States, as well as forecast information for other portions of the United States and abroad.

Seasonal Origins Of Soil Water Used By Trees, Scott T. Allen, James W. Kirchner, Sabine Braun, Rolf T. W. Siegwolf, Gregory R. Goldsmith

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Rain recharges soil water storages and either percolates downward into aquifers and streams or is returned to the atmosphere through evapotranspiration. Although it is commonly assumed that summer rainfall recharges plant-available water during the growing season, the seasonal origins of water used by plants have not been systematically explored. We characterize the seasonal origins of waters in soils and trees by comparing their midsummer isotopic signatures (δ2H) to seasonal isotopic cycles in precipitation, using a new seasonal origin index. Across 182 Swiss forest sites, xylem water isotopic signatures show that summer rain was not the predominant water source …

A Long-Term (2002 To 2017) Record Of Closed-Path And Open-Path Eddy Covariance Co2 Net Ecosystem Exchange Fluxes From The Siberian Arctic, David Holl, Christian Wille, Torsten Sachs, Peter Schreiber, Benjamin R. K. Runkle, Lutz Beckebanze, Moritz Langer, Julia Boike, Eva-Maria Pfeiffer, Irina Fedorova, Dimitry Y. Bolshianov, Mikhail N. Grigoriev, Lars Kutzbach

Biological and Agricultural Engineering Faculty Publications and Presentations

Ground-based observations of land–atmosphere fluxes are necessary to progressively improve global climate models. Observed data can be used for model evaluation and to develop or tune process models. In arctic permafrost regions, climate–carbon feedbacks are amplified. Therefore, increased efforts to better represent these regions in global climate models have been made in recent years. We present a multi-annual time series of land–atmosphere carbon dioxide fluxes measured in situ with the eddy covariance technique in the Siberian Arctic (72◦220 N, 126◦300 E). The site is part of the international network of eddy covariance flux observation stations (FLUXNET; site ID: Ru-Sam). The …

Identifying Causes Of Temporal Changes In Acropora Cervicornis Populations And The Potential For Recovery, Elizabeth Goergen, Alison L. Moulding, Brian K. Walker, David S. Gilliam

Marine & Environmental Sciences Faculty Articles

Corals, specifically the Atlantic staghorn coral, Acropora cervicornis, are under major threat as disturbance events such as storms and disease and predation outbreaks increase in frequency. Since its population declines due to a wide spread disease event in the early 1980s, limited long-term monitoring studies describing the impact of current threats and potential recovery have been completed. The aim of this study was to document the impacts of environmental (tropical storms, increased wind) and biological (disease and predation) threats on A. cervicornis to further understand its population dynamics and potential for recovery. Two high-density A. cervicornis patches (greater than …

Report Of The Workshop Evaluating The Nature Of Midwater Mining Plumes And Their Potential Effects On Midwater Ecosystems, Jeffrey C. Drazen, Craig R. Smith, Kristina Gjerde, Whitlow Au, Jesse Black, Glenn Carter, Malcolm Clark, Jennifer M. Durden, Pierre Dutrieux, Erica Goetze, Steven Haddock, Mariko Hatta, Chris Hauton, Paul Hill, Julian Koslow, Astrid B. Leitner, Chris Measures, Audre Pacini, Frank Parrish, Thomas Peacock, Jessica Perelman, Tracey T. Sutton, Celine Taymans, Verena Tunnicliffe, Les Watling, Hiroyuki Yamamoto, Emily Young, Amanda F. Ziegler

Marine & Environmental Sciences Faculty Articles

The International Seabed Authority (ISA) is developing regulations to control the future exploitation of deep-sea mineral resources including sulphide deposits near hydrothermal vents, polymetallic nodules on the abyssal seafloor, and cobalt crusts on seamounts. Under the UN Convention on the Law of the Sea the ISA is required to adopt are taking measures to ensure the effective protection of the marine environment from harmful effects arising from mining-related activities. Contractors are required to generate environmental baselines and assess the potential environmental consequences of deep seafloor mining. Understandably, nearly all environmental research has focused on the seafloor where the most direct …

Ecological Response Of Phytoplankton To The Oil Spills In The Oceans, Danling Tang, Jing Sun, Li Zhou, Sufen Wang, Ramesh P. Singh, Gang Pan

Mathematics, Physics, and Computer Science Faculty Articles and Research

Oil spills in oceans have substantial influence on marine ecosystems. This study investigates 21 oil spills in the world. Analyzing Chlorophyll-a (Chl-a) from Moderate Resolution Imaging Spectroradiomerer (MODIS) data after Penglai oil spills on 4 June 2011, found a bloom with peak value of Chl-a (13.66 mg m⁻³) spread over an area of 800 km² during 18–25 June 2011, and a pronounced increase in the monthly Chl-a concentration (6.40 mg m⁻³) on June 2012 in the Bohai Sea. Out of the 21 oil spills, 14 blooms were observed, while 11 …

Weather And Climate Summary And Forecast: February 2019 Report, Gregory V. Jones

Linfield University Wine Studies Reports

This report provides a summary of the weather and climate forecast for February 2019. It includes forecast information specific to the Pacific Northwest and the western United States, as well as forecast information for other portions of the United States and abroad.

Habitat Usage Patterns Of Bottlenose Dolphins (Tursiops Truncatus) In Terrebonne And Timbalier Bays, Louisiana, Mary Allison Manning

LSU Master's Theses

I coupled fine-scale environmental data with observed behavior and group composition data to examine overall distribution within the bay system and to characterize the habitat associated with foraging and the presence of calves. Semi-isolated populations of bottlenose dolphins (Tursiops truncatus) along Louisiana’s coast are undergoing increased risks from boat traffic, oil spills, land subsidence, and planned water diversions (CPRA 2017). Characterizing the habitat use of bottlenose dolphins in Terrebonne and Timbalier bays, Louisiana, is important given the likely high site fidelity, small home ranges, and low exchange of individuals with nearby coastal populations (Lane et al. 2015, McDonald …

Evaluation Of An Educational Campaign To Improve The Conscious Consumption Of Recreationally Caught Fish, Corey A. Krabbenhoft, Susan Manente, Donna R. Kashian

Environmental Science and Geology Faculty Research Publications

Consumption guidelines are a common way of improving conscious consumption behaviors in areas where game fish are known to contain contaminants. However, guideline information can be difficult to distribute, and effectiveness difficult to measure. To increase the distribution and effectiveness of guideline information for the Detroit River, an educational campaign was launched in 2010, which included distribution of pamphlets with consumption information, posting of permanent signs at popular fishing locations, and hiring River Walkers to personally communicate with anglers. In 2013 and 2015, we conducted in-person surveys of active shoreline anglers to determine the effectiveness of education and outreach efforts. …

Recurring Episodes Of Thermal Stress Shift The Balance From A Dominant Host-Specialist To A Background Host-Generalist Zooxanthella In The Threatened Pillar Coral, Dendrogyra Cylindrus, Cynthia Lewis, Karen L. Neely, Mauricio Rodriguez-Lanetty

Marine & Environmental Sciences Faculty Articles

Most scleractinian corals form obligate symbioses with photosynthetic dinoflagellates (family Symbiodiniaceae), which provide differential tolerances to their host. Previously, research has focused on the influence of symbiont composition and the dynamic processes of symbiont repopulation during single episodes of hyperthermal events, followed by years of less-stressful conditions. In contrast, this study characterized for the first time, the role of Symbiodiniaceae species changes in response to annually recurring hyperthermal events, a scenario soon expected to become the norm. Consecutive hyperthermal events during summer 2014 and 2015 along the Florida Reef Tract offered a unique opportunity to study bleaching susceptibility and recovery …

Global Patterns And Drivers Of Ecosystem Functioning In Rivers And Riparian Zones, Scott Tiegs, David Costello, Mark W. Isken, Guy Woodward, Peter B. Mcintyre, Mark O. Gessner, Amy Marcarelli, Et. Al.

Department of Biological Sciences Publications

River ecosystems receive and process vast quantities of terrestrial organic carbon, the fate of which depends strongly on microbial activity. Variation in and controls of processing rates, however, are poorly characterized at the global scale. In response, we used a peer-sourced research network and a highly standardized carbon processing assay to conduct a global-scale field experiment in greater than 1000 river and riparian sites. We found that Earth’s biomes have distinct carbon processing signatures. Slow processing is evident across latitudes, whereas rapid rates are restricted to lower latitudes. Both the mean rate and variability decline with latitude, suggesting temperature constraints …

Weather And Climate Summary And Forecast: January 2019 Report, Gregory V. Jones

Linfield University Wine Studies Reports

This report provides a summary of the weather and climate forecast for January 2019. It includes forecast information specific to the Pacific Northwest and the western United States, as well as forecast information for other portions of the United States and abroad.

Comparisons Of Five Dna Repair Pathways Between Elasmobranch Fishes And Humans, Lucia Llorente

HCNSO Student Theses and Dissertations

Although DNA repair capacity has been correlated with lifespan in terrestrial vertebrate species, it remains unknown how evolutionarily conserved the process is across all vertebrate taxa. In particular, chondrichthyan fishes have lifespans that range from 3-350 years and they are evolutionarily separated from modern humans Homo sapiens by approximately 400 million years. We hypothesized that chondrichthyan fishes would show significant homology in nuclear excision repair (NER) genes with humans, and that the expression of NER genes will correlate with the lifespan of the respective assessed species. For this study, DNA repair gene homology and expression was performed on the nurse …

Creative Citizen Science Illuminates Complex Ecological Responses To Climate Change, Abraham J. Miller-Rushing, Amanda S. Gallinat, Richard B. Primack

Biology Faculty Publications

Climate change is causing the timing of key behaviors (i.e., phenology) to shift differently across trophic levels and among some interacting organisms (e.g., plants and pollinators, predators and prey), suggesting that interactions among species are being disrupted (1, 2). Studying the phenology of interactions, however, is difficult, which has limited researchers’ ability to zero in on changes in specific interactions or on the consequences of mismatches. In PNAS, Hassall et al. (3) use a combination of citizen science techniques to investigate the effects of climate change on dozens of specific interactions. They focus on a Batesian mimicry complex involving stinging …

Air Quality And Health Burden Of 2017 Northern California Wildfires, Susan O’Neill, Minghui Diao

Faculty Publications, Meteorology and Climate Science

No abstract provided.

Vintage Report 2018: North Willamette Valley, Gregory V. Jones

Linfield University Wine Studies Reports

This report describes the impacts of climate and phenology on vintage for the North Willamette Valley in Oregon in 2018. A relatively mild and dry winter set the stage for a 2018 growing season that was highlighted by a cool spring, a summer with low heat stress but high drought stress along with numerous regional fires, and a glorious October. The moderately cool spring led to a late start to the growing season with an average bud break of April 17th delayed by 5-10 days compared to average. However, a warm May through August brought plant growth timing to near …

Winter Snow Depth In Arctic Alaska Results In Complex Changes In Caribou Forage Quality, Jessica C. Richert

Electronic Theses and Dissertations

Caribou (Rangifer tarandus) rely on the short growing season for much of their annual nutrition, making them susceptible to even small changes in forage quantity and quality. Body condition in the summer and fall is linked to winter survival rates and fecundity in cows, critical factors in the robustness of caribou populations. Due to a warmer, wetter climate, snowfall is predicted to increase over Alaska’s North Slope in the next several decades. Deeper snow results in higher soil temperatures, allowing microbial mineralization of nitrogen to continue throughout the winter and increasing the availability of nitrogen for plants in spring and …

Bomb Radiocarbon Age Validation For The Long-Lived, Unexploited Arctic Fish Species Coregonus Clupeaformis, John M. Casselman, Cynthia M. Jones, Steven E. Campana

OES Faculty Publications

The growth rates of freshwater fish in the Arctic would be expected to be very low, but some previous studies of lake whitefish (Coregonus clupeaformis) have reported relatively rapid growth and longevity estimates of less than 15 years. We used bomb radiocarbon chronologies to validate an ageing method based on otolith sections for lake whitefish in both an unexploited Arctic lake (MacAlpine Lake; longevity 50 years) and a lightly exploited temperate population (Lake Simcoe; longevity 49 years). Our results confirm previous suggestions that other ageing methods can seriously underestimate lake whitefish age after ~5–8 years. A Chapman–Robson estimate …

Dinitrogen Fixation Across Physico-Chemical Gradients Of The Eastern Tropical North Pacific Oxygen Deficient Zone, C. R. Selden, M. R. Mulholland, P.W. Bernhardt, B. Widner, A. Macías-Tapia, Q. Ji, A. Jayakumar

OES Faculty Publications

The Eastern Tropical North Pacific Ocean hosts one of the world's largest oceanic oxygen deficient zones (ODZs). Hot spots for reactive nitrogen (N_r) removal processes, ODZs generate conditions proposed to promote N_r inputs via dinitrogen (N₂) fixation. In this study, we quantified N₂ fixation rates by ¹⁵N tracer bioassay across oxygen, nutrient, and light gradients within and adjacent to the ODZ. Within subeuphotic oxygen‐deplete waters, N₂ fixation was largely undetectable; however, addition of dissolved organic carbon stimulated N₂ fixation in suboxic (μmol/kg O₂) waters, suggesting that diazotroph communities are …

Ebullition Of Oxygen From Seagrasses Under Supersaturated Conditions, Matthew H. Long, Kevin Sutherland, Scott D. Wankel, David J. Burdige, Richard C. Zimmerman

OES Faculty Publications

Gas ebullition from aquatic systems to the atmosphere represents a potentially important fraction of primary production that goes unquantified by measurements of dissolved gas concentrations. Although gas ebullition from photosynthetic surfaces has often been observed, it is rarely quantified. The resulting underestimation of photosynthetic activity may significantly bias the determination of ecosystem trophic status and estimated rates of biogeochemical cycling from in situ measures of dissolved oxygen. Here, we quantified gas ebullition rates in Zostera marina meadows in Virginia, U.S.A. using simple funnel traps and analyzed the oxygen concentration and isotopic composition of the captured gas. Maximum hourly rates of …

Metagenomic Sequencing Identifies Highly Diverse Assemblages Of Dinoflagellate Cysts In Sediments From Ships' Ballast Tanks, Lixia Shang, Zhangxi Hu, Yunyan Deng, Yuyang Liu, Xinyu Zhai, Zhaoyang Chai, Xiaohan Liu, Zifeng Zhan, Fred C. Dobbs, Ying Zhong Tang

OES Faculty Publications

Ships' ballast tanks have long been known as vectors for the introduction of organisms. We applied next-generation sequencing to detect dinoflagellates (mainly as cysts) in 32 ballast tank sediments collected during 2001-2003 from ships entering the Great Lakes or Chesapeake Bay and subsequently archived. Seventy-three dinoflagellates were fully identified to species level by this metagenomic approach and single-cell polymerase chain reaction (PCR)-based sequencing, including 19 toxic species, 36 harmful algal bloom (HAB) forming species, 22 previously unreported as producing cysts, and 55 reported from ballast tank sediments for the first time (including 13 freshwater species), plus 545 operational taxonomic units …

Spatial Structuring And Life History Connectivity Of Antarctic Silverfish Along The Southern Continental Shelf Of The Weddell Sea, Jilda Alicia Caccavo, Julian R. Ashford, Svenja Ryan, Chiara Papetti, Michael Schröder, Lorenzo Zane

OES Faculty Publications

A multi-disciplinary approach was employed to examine a physical-biological population hypothesis for a critical forage species, the Antarctic silverfish Pleuragramma antarctica. Caccavo et al. (2018; Sci Rep 8:17856) had shown strong gene flow along the westward Antarctic Slope Current, in addition to spatially recurring length modes that provided evidence for episodic connectivity. In this paper, otolith nucleus chemistry from a subset of fish collected in the southern Weddell Sea as part of a hydrographic survey of the Filchner Trough system was used to test between connectivity scenarios. Nucleus chemistry, which reflects environmental exposure during early life, showed significant …

A Full-Ocean-Depth Rated Modular Lander And Pressure-Retaining Sampler Capable Of Collecting Hadal-Endemic Microbes Under In Situ Conditions, Logan M. Peoples, Matthew Norenberg, David Price, Madeline Mcgoldrick, Mark Novotny, Alexander Bochdansky, Douglas H. Bartlett

OES Faculty Publications

The hadal zone remains one of the least studied environments because of its inaccessibility, in part because of hydrostatic pressures extending to 110 MPa. Few instruments are capable of sampling from such great depths. We have developed a full-ocean-depth-capable lander that can be fit with sampling packages for the collection of still images, video, motile megafauna, and hadal seawater. One payload includes a pressure-retaining sampler (PRS) able to maintain seawater samples under in situ pressure during recovery. We describe the technical specifications of the lander and the PRS and preliminary results from three deployments at depths in excess of 10,700 …

Patterns Of Diatom Diversity Correlate With Dissolved Trace Metal Concentrations And Longitudinal Position In The Notheast Pacific Coastal Offshore Transition Zone, P. Dreux Chappell, E. Virginia Armbrust, Katherine A. Barbeau, Randelle M. Bundy, Jagruti Vedamati, Bethany D. Jenkins

OES Faculty Publications

Diatoms are important primary producers in the northeast Pacific Ocean, with their productivity closely linked to pulses of trace elements in the western high nitrate, low chlorophyll (HNLC) region of the oceanographic time series transect 'Line P.' Recently, the coastal-HNLC transition zone of the Line P transect was identified as a hotspot of phytoplankton productivity, potentially controlled by a combination of trace element and macronutrient concentrations. Here we describe diatom community composition in the eastern Line P transect, including the coastal- HNLC transition zone, with a method using high-throughput sequencing of diatom 18S gene amplicons. We identified significant correlations between …

Metaproteomics Reveal That Rapid Perturbations In Organic Matter Prioritize Functional Restructuring Over Taxonomy In Western Arctic Ocean Microbiomes, Molly P. Mikan, H. Rodger Harvey, Emma Timmins-Schiffman, Michael Riffle, Damon H. May, Ian Salter, William S. Noble, Brook L. Nunn

OES Faculty Publications

We examined metaproteome profiles from two Arctic microbiomes during 10-day shipboard incubations to directly track early functional and taxonomic responses to a simulated algal bloom and an oligotrophic control. Using a novel peptide-based enrichment analysis, significant changes (p-value < 0.01) in biological and molecular functions associated with carbon and nitrogen recycling were observed. Within the first day under both organic matter conditions, Bering Strait surface microbiomes increased protein synthesis, carbohydrate degradation, and cellular redox processes while decreasing C1 metabolism. Taxonomic assignments revealed that the core microbiome collectively responded to algal substrates by assimilating carbon before select taxa utilize and metabolize nitrogen intracellularly. Incubations of Chukchi Sea bottom water microbiomes showed similar, but delayed functional responses to identical treatments. Although 24 functional terms were shared between experimental treatments, the timing, and degree of the remaining responses were highly variable, showing that organic matter perturbation directs community functionality prior to alterations to the taxonomic distribution at the microbiome class level. The dynamic responses of these two oceanic microbial communities have important implications for timing and magnitude of responses to organic perturbations within the Arctic Ocean and how community-level functions may forecast biogeochemical gradients in oceans.

Nitrogen Assimilation In Picocyanobacteria Inhabiting The Oxygen-Deficient Waters Of The Eastern Tropical North And South Pacific, Montserrat Aldunate, Carlos Henriquez-Castillo, Qixing Ji, Jessica Lueders-Dumont, Margaret R. Mulholland, Bess B. Ward, Peter Von Dassow, Osvaldo Ulloa

OES Faculty Publications

Prochlorococcus and Synechococcus are the most abundant free-living photosynthetic microorganisms in the ocean. Uncultivated lineages of these picocyanobacteria also thrive in the dimly illuminated upper part of oxygen-deficient zones (ODZs), where an important portion of ocean nitrogen (N) loss takes place via denitrification and anaerobic ammonium oxidation. Recent metagenomic studies revealed that ODZ Prochlorococcus have the genetic potential for using different N forms, including nitrate and nitrite, uncommon N sources for Prochlorococcus, but common for Synechococcus. To determine which N sources ODZ picocyanobacteria are actually using in nature, the cellular 15N natural abundance (δ15N) and assimilation rates of …

Dust Storms And The Dispersal Of Aquatic Invertebrates In The Chihuahuan Desert Ecoregion, Jose Rivas Jr.

Open Access Theses & Dissertations

The Chihuahuan Desert surrounding El Paso, Texas is one of the most intense sources of dust in the Western Hemisphere. Within this vast desert are ephemeral wetlands with micrometazoan propagules contained within their sediment egg banks. Dispersal of aquatic microinvertebrates between habitats is vital for the success of their populations. Passive dispersal of the propagules provides an escape mechanism from unfavorable conditions. Upon desiccation of these habitats, windstorms can potentially transport propagules mixed within entrained sediments across regional scales. To study this process, I collected falling sediment from 91 windstorms, with 59 samples collected at the University of Texas at …

Modeling The Seasonal Cycle Of Iron And Carbon Fluxes In The Amundsen Sea Polynya, Antarctica, P. St-Laurent, P. L. Yager, R. M. Sherrell, H. Oliver, M. S. Dinniman, S. E. Stammerjohn

CCPO Publications

The Amundsen Sea Polynya (ASP) is distinguished by having the highest net primary production per unit area in the coastal Antarctic. Recent studies have related this high productivity to the presence of fast-melting ice shelves, but the mechanisms involved are not well understood. In this study we describe the first numerical model of the ASP to represent explicitly the ocean-ice interactions, nitrogen and iron cycles, and the coastal circulation at high resolution. The study focuses on the seasonal cycle of iron and carbon, and the results are broadly consistent with field observations collected during the summer of 2010–2011. The simulated …

Through The Eyes Of Locals: A Changing Climate In Bolivia, Jacob D. Rex

Undergraduate Theses, Professional Papers, and Capstone Artifacts

Deforestation and Agricultural Land-Use Change in Bolivia as a Function of Socio-Economic Realities.

This research combines semi-structured interviews of key informants and local participants, as well as field observations, which were conducted between January and April of 2019 in the Departments of Santa Cruz & Chuquisaca.