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Articles 271 - 300 of 436

Full-Text Articles in Marine Biology

A Snapshot Of The Age, Growth, And Reproductive Status Of Gray Triggerfish (Balistes Capriscus, Gmelin 1789) On Three Artificial Reefs In The Northwest Gulf Of Mexico, Adam M. Lee May 2019

A Snapshot Of The Age, Growth, And Reproductive Status Of Gray Triggerfish (Balistes Capriscus, Gmelin 1789) On Three Artificial Reefs In The Northwest Gulf Of Mexico, Adam M. Lee

Theses and Dissertations

Age, growth, and reproductive status of gray triggerfish (Balistes capriscus) were identified from 2015-2016 on artificial reefs in the northwest Gulf of Mexico. Individuals ranged from 232-432 mm fork length with and a mean fork length of 319 mm. Individuals from age 0.2 to 5.2 yrs were observed with a weight to length relationship of Wg = 1.1 x -104 x FL2.7 (r2 = 0.94, n = 112), where FL = fork length (mm) and Wg = weight (g). A von Bertalanffy growth equation of Lt = 326(1 - e - 0.9 (t + 1.71)) was calculated irrespective …


The Sedimentology Of Cay Sal Bank - An Incipiently Drowned Carbonate Platform, Luis Ramirez Apr 2019

The Sedimentology Of Cay Sal Bank - An Incipiently Drowned Carbonate Platform, Luis Ramirez

HCNSO Student Theses and Dissertations

Sediment on Cay Sal Bank (CSB) is characterized by its coarse-grain size, poor sorting, predominance of skeletal fragments, and relatively depleted d18O isotope values. CSB is an incipiently drowned platform in close proximity to the Great Bahama Bank (GBB), a carbonate platform which is not incipiently drowned and characterized by fine-grained, non-skeletal sediment. The GBB has locally well-developed oolitic grainstone facies and coral reef margins, which are both lacking on CSB. Platform-top water depths on the GBB are typically 10 m or less, but CSB depth ranges between 7 and 30 m. CSB is devoid of mud, whereas …


Evaluating A New Algorithm For Satellite-Based Evapotranspiration For North American Ecosystems: Model Development And Validation, Bassil El Masri, Abdullah F. Rahman, Danilo Dragoni Apr 2019

Evaluating A New Algorithm For Satellite-Based Evapotranspiration For North American Ecosystems: Model Development And Validation, Bassil El Masri, Abdullah F. Rahman, Danilo Dragoni

School of Earth, Environmental, & Marine Sciences Faculty Publications

Highlights

  • We developed an algorithm to estimate evapotranspiration based solely on satellite data.

  • Our model is able to track the seasonal changes in the flux tower observations.

  • The errors in the model ET output were lower than the MODIS ET product.

  • The modeled and observed ET strong relationship implies that our model has the potential to be applied to different ecosystems.

Abstract

We introduce a different operational approach to estimate 8-day average daily evapotranspiration (ET) using both routinely available data and the Penman-Monteith (P-M) equation for canopy transpiration and evaporation of intercepted water and Priestley and Taylor for soil evaporation. …


Vaquita Face Extinction From Bycatch. Comment On Manjarrez-Bringas, N. Et Al., Lessons For Sustainable Development: Marine Mammal Conservation Policies And Its Social And Economic Effects., Karl W. Flessa, Luis Calderon-Aguilera, Carlos E. Cintra-Buenrostro, David L. Dettman, Gregory P. Dietl, David H. Goodwin, David K. Jacobs, Michal Kowalewski, Steven M. Nelson, Kirsten Rowell, Bernard R. Schone, Jansen A. Smith, Francisco Zamora-Arroyo Apr 2019

Vaquita Face Extinction From Bycatch. Comment On Manjarrez-Bringas, N. Et Al., Lessons For Sustainable Development: Marine Mammal Conservation Policies And Its Social And Economic Effects., Karl W. Flessa, Luis Calderon-Aguilera, Carlos E. Cintra-Buenrostro, David L. Dettman, Gregory P. Dietl, David H. Goodwin, David K. Jacobs, Michal Kowalewski, Steven M. Nelson, Kirsten Rowell, Bernard R. Schone, Jansen A. Smith, Francisco Zamora-Arroyo

School of Earth, Environmental, & Marine Sciences Faculty Publications

We are among the scientists who have documented the environmental and ecological changes to the Upper Gulf of California following the reduction in the Colorado River’s flow. We object to any suggestion that our research supports Manjarrez-Bringas et al.’s conclusion that the decline in the Colorado River’s flow is the reason for the decline in the population of the endangered vaquita porpoise (Phocoena sinus). Manjarrez-Bringas et al.’s conclusions are incongruent with their own data, their logic is untenable, their analyses fail to consider current illegal fishing practices, and their recommendations are unjustified and misdirected. Vaquita face extinction because of bycatch, …


Molecular Cloning And Characterization Of Two Arnt (Arnt-1 And Arnt-2) Genes In Atlantic Croaker And Their Expression During Coexposure To Hypoxia And Pcb77, Md. Saydur Rahman, Peter Thomas Feb 2019

Molecular Cloning And Characterization Of Two Arnt (Arnt-1 And Arnt-2) Genes In Atlantic Croaker And Their Expression During Coexposure To Hypoxia And Pcb77, Md. Saydur Rahman, Peter Thomas

School of Earth, Environmental, & Marine Sciences Faculty Publications

Aryl hydrocarbon receptor nuclear translocator (ARNT) is an important transcriptions factor that binds/coactivates drug-metabolizing genes in vertebrates. In this study, we report the cloning and characterization of two ARNT (ARNT-1 and ARNT-2) genes and their mRNA and protein expression in liver tissues of Atlantic croaker after co-exposure to hypoxia and 3,3',4,4'-tetrachlorobiphenyl (PCB77). The full-length croaker ARNT-1 and ARNT-2 genes encode proteins of 537 and 530 amino acids, respectively, and are highly homologous to ARNT-1 and ARNT-2 genes of other vertebrates. ARNT mRNAs are ubiquitously expressed in all tissues. Hypoxia (dissolved oxygen: 1.7 mg/L) exposure (1-4 weeks) did not affect hepatic …


Ocean Robots Uncover Microbial Secrets, Susan Evans, Jim Birch, John A. Breier, Michael V. Jakuba, Mak A. Saito, Julie Robidart Feb 2019

Ocean Robots Uncover Microbial Secrets, Susan Evans, Jim Birch, John A. Breier, Michael V. Jakuba, Mak A. Saito, Julie Robidart

School of Earth, Environmental, & Marine Sciences Faculty Publications

Life on Earth began in the sea, and the oceans continue to support life on our planet. Of particular importance is the ability of marine microbes to exist in a complex web of relationships where substances are continually transformed and exchanged.


A Heuristic Classification Of Woody Plants Based On Contrasting Shade And Drought Strategies, Liang Wei, Chonggang Xu, Steven Jansen, Hang Zhou, Bradley O. Christoffersen, William T. Pockman, Richard S. Middleton, John D. Marshall, Nate G. Mcdowell Jan 2019

A Heuristic Classification Of Woody Plants Based On Contrasting Shade And Drought Strategies, Liang Wei, Chonggang Xu, Steven Jansen, Hang Zhou, Bradley O. Christoffersen, William T. Pockman, Richard S. Middleton, John D. Marshall, Nate G. Mcdowell

School of Earth, Environmental, & Marine Sciences Faculty Publications

Woody plants vary in their adaptations to drought and shade. For a better prediction of vegetation responses to drought and shade within dynamic global vegetation models, it is critical to group species into functional types with similar adaptations. One of the key challenges is that the adaptations are generally determined by a large number of plant traits that may not be available for a large number of species. In this study, we present two heuristic woody plant groups that were separated using cluster analysis in a three-dimensional trait–environment space based on three key metrics for each species: mean xylem embolism …


Complete Mitochondrial Genome Of Callogorgia Cf. Gracilis (Octocorallia: Calcaxonia: Primnoidae), Erin E. Easton, David Hicks Jan 2019

Complete Mitochondrial Genome Of Callogorgia Cf. Gracilis (Octocorallia: Calcaxonia: Primnoidae), Erin E. Easton, David Hicks

School of Earth, Environmental, & Marine Sciences Faculty Publications

We report the first complete mitochondrial genome of Callogorgia. Callogorgia cf. gracilis isolate DFH32_518B was collected by a remotely operated vehicle at 98 m on McGrail Bank (27.9840725°N, 92.604242°W). The complete mitogenome is 18,937 bp (27.8% A, 18.3% C, 19.8% G, and 34.1% T) and has the ancestral octocoral gene order for its 14 protein-coding genes, two rRNA genes, and one tRNA gene. It is sister to and ∼96.6% similar (uncorrected) to Narella hawaiiensis, the only other complete mitogenome reported for Primnoidae. The cox1 + igr1 + mtMutS region differs by two base pairs (0.12%) from the only reported …


A High-Latitude, Mesophotic Cycloseris Field At 85 M Depth Off Rapa Nui (Easter Island), Bert W. Hoeksema, Javier Sellanes, Erin E. Easton Jan 2019

A High-Latitude, Mesophotic Cycloseris Field At 85 M Depth Off Rapa Nui (Easter Island), Bert W. Hoeksema, Javier Sellanes, Erin E. Easton

School of Earth, Environmental, & Marine Sciences Faculty Publications

Published records of mesophotic zooxanthellate corals from Rapa Nui (Easter Island) are rare and so far based only on dredged specimens and observations during scuba dives (Wells 1972, Glynn et al. 2003, 2007). During recent remotely operated vehicle (ROV) surveys off Rapa Nui (March 2016), a large and dense aggregation of zooxanthellate Cycloseris corals (Scleractinia: Fungiidae) with a density of approximately 500 ind m−2 was discovered (27°08΄55˝S, 109°26΄46˝W) on black sand in a depth range of approximately 79–85 m (Panels A, B). A few corals were overturned, exposing their white (azooxanthellate) undersides and sutures along which self-fragmentation took place (Panel …


Measuring, Mapping And Quantifying The Effects Of Trust And Informal Communication On Transboundary Collaboration In The Great Lakes Fisheries Policy Network, Andrew M. Song, Owen Temby, Dongkyu Kim, Angel Saavedra Cisneros, Gordon M. Hickey Jan 2019

Measuring, Mapping And Quantifying The Effects Of Trust And Informal Communication On Transboundary Collaboration In The Great Lakes Fisheries Policy Network, Andrew M. Song, Owen Temby, Dongkyu Kim, Angel Saavedra Cisneros, Gordon M. Hickey

School of Earth, Environmental, & Marine Sciences Faculty Publications

Ecosystem-based management of fisheries and other transboundary natural resources require a number of organizations across jurisdictions to exchange knowledge, coordinate policy goals and engage in collaborative activities. Trust, as part of social capital, is considered a key mechanism facilitating the coordination of such inter-organizational policy networks. However, our understanding of multi-dimensional trust as a theoretical construct and an operational variable in environmental and natural resource management has remained largely untested. This paper presents an empirical assessment of trust and communication measures applied to the North American Great Lakes fisheries policy network. Using a scale-based method developed for this purpose, we …


Island Invasion: The Silent Crisis In Hawaii, Sophia Janssen Jan 2019

Island Invasion: The Silent Crisis In Hawaii, Sophia Janssen

Pomona Senior Theses

Keeping out invasive species may, upon first review, seem like a trivial environmental cry from ecologists and deep environmentalists; a belated wish to return to an undeveloped world where nature was pristine. However invasive species create problems that impact all of us and can have far more severe consequences than changing a stunning landscape. These problems are heightened in islands like Hawaii, where the fragile ecosystems have developed over centuries of evolution and adaptation. The introduction of a disease-carrying mosquito can put the people of Hawaii at risk to many vector-born illnesses and create an epidemic, taking human life. The …


Rapidly Expanding Nuclear Arsenals In Pakistan And India Portend Regional And Global Catastrophe, Owen B. Toon, Charles G. Bardeen, Alan Robock, Lili Xia, Hans Kristensen, Matthew Mckinzie, R. J. Peterson, Cheryl S. Harrison, Nicole S. Lovenduski, Richard P. Turco Jan 2019

Rapidly Expanding Nuclear Arsenals In Pakistan And India Portend Regional And Global Catastrophe, Owen B. Toon, Charles G. Bardeen, Alan Robock, Lili Xia, Hans Kristensen, Matthew Mckinzie, R. J. Peterson, Cheryl S. Harrison, Nicole S. Lovenduski, Richard P. Turco

School of Earth, Environmental, & Marine Sciences Faculty Publications

Pakistan and India may have 400 to 500 nuclear weapons by 2025 with yields from tested 12- to 45-kt values to a few hundred kilotons. If India uses 100 strategic weapons to attack urban centers and Pakistan uses 150, fatalities could reach 50 to 125 million people, and nuclear-ignited fires could release 16 to 36 Tg of black carbon in smoke, depending on yield. The smoke will rise into the upper troposphere, be self-lofted into the stratosphere, and spread globally within weeks. Surface sunlight will decline by 20 to 35%, cooling the global surface by 2° to 5°C and reducing …


Sweet Potato: A Potentially Profitable Summer Crop For South Texas Organic Farmers To Enhance Soil Biological Activity And Nutrient Release, Jahdiel Salazar, Josabeth Navarro, James Jihoon Kang, Engil Isadora Pujol Pereira Jan 2019

Sweet Potato: A Potentially Profitable Summer Crop For South Texas Organic Farmers To Enhance Soil Biological Activity And Nutrient Release, Jahdiel Salazar, Josabeth Navarro, James Jihoon Kang, Engil Isadora Pujol Pereira

School of Earth, Environmental, & Marine Sciences Faculty Publications

No abstract provided.


Past, Present, And Future Perspectives Of Environmental Dna (Edna) Metabarcoding: A Systematic Review In Methods, Monitoring, And Applications Of Global Edna, Krista M. Ruppert, Richard J. Kline, Md. Saydur Rahman Jan 2019

Past, Present, And Future Perspectives Of Environmental Dna (Edna) Metabarcoding: A Systematic Review In Methods, Monitoring, And Applications Of Global Edna, Krista M. Ruppert, Richard J. Kline, Md. Saydur Rahman

School of Earth, Environmental, & Marine Sciences Faculty Publications

Environmental DNA (eDNA) metabarcoding is a novel method of assessing biodiversity wherein samples are taken from the environment via water, sediment or air from which DNA is extracted, and then amplified using general or universal primers in polymerase chain reaction and sequenced using next-generation sequencing to generate thousands to millions of reads. From this data, species presence can be determined, and overall biodiversity assessed. It is an interdisciplinary method that brings together traditional fieldbased ecology with in-depth molecular methods and advanced computational tools. As an emerging monitoring method, there are many pitfalls and roadblocks to be considered and avoided, but …


Measuring Connective Capacity Throughout The Gulf Of Mexico Fishery Management Network, Anthony Rocha Lima Dec 2018

Measuring Connective Capacity Throughout The Gulf Of Mexico Fishery Management Network, Anthony Rocha Lima

Theses and Dissertations

The Gulf of Mexico provides substantial resources along its 1,680-mile coastline, spanning 5 U.S. states and providing millions of pounds of seafood and hundreds of millions in revenue annually. Continued success of the fishery relies on the ability of a large, complex, multiagency network to find the best solutions to balance the needs of humans, as well as ensure long-term sustainability. Organizations with varying objectives require effective communication when addressing intricate ecosystem-based management topics such as endangered species and regional economies.

To better understand the connectivity within the Gulf fishery management network, an IRB reviewed survey was dispersed to the …


Using Carbon Isotope Fractionation To Constrain The Extent Of Methane Dissolution Into The Water Column Surrounding A Natural Hydrocarbon Gas Seep In The Northern Gulf Of Mexico, M. Leonte, B. Wang, Scott A. Socolofsky, John A. Breier, John D. Kessler Nov 2018

Using Carbon Isotope Fractionation To Constrain The Extent Of Methane Dissolution Into The Water Column Surrounding A Natural Hydrocarbon Gas Seep In The Northern Gulf Of Mexico, M. Leonte, B. Wang, Scott A. Socolofsky, John A. Breier, John D. Kessler

School of Earth, Environmental, & Marine Sciences Faculty Publications

A gas bubble seep located in the northern Gulf of Mexico was investigated over several days to determine whether changes in the stable carbon isotopic ratio of methane can be used as a tracer for methane dissolution through the water column. Gas bubble and water samples were collected at the seafloor and throughout the water column for isotopic ratio analysis of methane. Our results show that changes in methane isotopic ratios are consistent with laboratory experiments that measured the isotopic fractionation from methane dissolution. A Rayleigh isotope model was applied to the isotope data to determine the fraction of methane …


Mesobot : An Autonomous Underwater Vehicle For Tracking And Sampling Midwater Targets, Dana R. Yoerger, Molly Curran, Justin Fujii, Christopher R. German, Daniel Gomez-Ibanez, Annette F. Govindarajan, Jonathan C. Howland, Joel K. Llopiz, Peter H. Wiebe, Brett W. Hobson, Kakani Katija, Michael Risi, Bruce H. Robison, Cailean J. Wilkinson, Stephen M. Rock, John A. Breier Nov 2018

Mesobot : An Autonomous Underwater Vehicle For Tracking And Sampling Midwater Targets, Dana R. Yoerger, Molly Curran, Justin Fujii, Christopher R. German, Daniel Gomez-Ibanez, Annette F. Govindarajan, Jonathan C. Howland, Joel K. Llopiz, Peter H. Wiebe, Brett W. Hobson, Kakani Katija, Michael Risi, Bruce H. Robison, Cailean J. Wilkinson, Stephen M. Rock, John A. Breier

School of Earth, Environmental, & Marine Sciences Faculty Publications

Mesobot, a new class of autonomous underwater vehicle, will address specific unmet needs for observing slow-moving targets in the midwater ocean. Mesobot will track targets such as zooplankton, fish, and descending particle aggregates using a control system based on stereo cameras and a combination of thrusters and a variable buoyancy system. The vehicle will also be able to collect biogeochemical and environmental DNA (eDNA) samples using a pumped filter sampler.


Development Of Hurricane Storm Surge Model To Predict Coastal Highway Inundation For South Texas, Sara E. Davila, Adan Garza, Jungseok Ho Sep 2018

Development Of Hurricane Storm Surge Model To Predict Coastal Highway Inundation For South Texas, Sara E. Davila, Adan Garza, Jungseok Ho

School of Earth, Environmental, & Marine Sciences Faculty Publications

Forecasting areas prone to flooding will allow us to send off our information gathered to departments such as TxDOT and the United States Department of Transportation. This would then enable these departments to create appropriate evacuation routes, depicting which roads are clear and which cannot be used in the event of a storm. Simulating hurricanes that have passed through this area such as Dolly in 2008, Beulah in 1967, and Bret in 1999 will display the roads and federal highways that frequently tend to get flooded. Identifying the “danger roads” and which federal highways will ultimately be useful for various …


Climate And Plant Controls On Soil Organic Matter In Coastal Wetlands, Michael J. Osland, Christopher A. Gabler, James B. Grace, Richard H. Day, Meagan L. Mccoy, Jennie L. Mcleod, Andrew S. From, Nicholas M. Enwright, Laura C. Feher, Camille L. Stagg Jun 2018

Climate And Plant Controls On Soil Organic Matter In Coastal Wetlands, Michael J. Osland, Christopher A. Gabler, James B. Grace, Richard H. Day, Meagan L. Mccoy, Jennie L. Mcleod, Andrew S. From, Nicholas M. Enwright, Laura C. Feher, Camille L. Stagg

School of Earth, Environmental, & Marine Sciences Faculty Publications

Coastal wetlands are among the most productive and carbon‐rich ecosystems on Earth. Long‐term carbon storage in coastal wetlands occurs primarily belowground as soil organic matter (SOM). In addition to serving as a carbon sink, SOM influences wetland ecosystem structure, function, and stability. To anticipate and mitigate the effects of climate change, there is a need to advance understanding of environmental controls on wetland SOM. Here, we investigated the influence of four soil formation factors: climate, biota, parent materials, and topography. Along the northern Gulf of Mexico, we collected wetland plant and soil data across elevation and zonation gradients within 10 …


First Record Of Black Corals (Antipatharia) In Shallow Coastal Waters Of Northern Chile By Means Of Underwater Video, Matthias Gorny, Erin E. Easton, Javier Sellanes Jun 2018

First Record Of Black Corals (Antipatharia) In Shallow Coastal Waters Of Northern Chile By Means Of Underwater Video, Matthias Gorny, Erin E. Easton, Javier Sellanes

School of Earth, Environmental, & Marine Sciences Faculty Publications

This record is the first report of black corals (Antipatharia) in shallow waters of the continental coast of Chile, and extends their geographical range in shallow waters of the upper continental shelf of South America by ~3000 km from Ecuador (~1°S) to Coquimbo, Chile (~29°S). Specimens were observed between 70 and 107 m on three underwater video transects executed in July 2016 on the rocky reef El Toro, which is located about 65 km northwest of Coquimbo. The images were taken with the cameras of a remotely operated vehicle (ROV) at a distance of about two meters from the rocks. …


Extraction Of Metazoan Meiofauna From Muddy Deep-Sea Samples: Operator And Taxon Effects On Efficiency, Melissa Rohal, David Thistle, Erin E. Easton May 2018

Extraction Of Metazoan Meiofauna From Muddy Deep-Sea Samples: Operator And Taxon Effects On Efficiency, Melissa Rohal, David Thistle, Erin E. Easton

School of Earth, Environmental, & Marine Sciences Faculty Publications

Deep-sea metazoan meiofaunal specimens are usually extracted from muddy samples by centrifugation in a fluid in which meiofauna tend to float and sediment particles tend to sink. Although the procedure is in common use, its efficiency has seldom been examined. The study reported here showed that well-trained operators extracted metazoan meiofauna with efficiencies that were different enough to be a concern in quantitative studies. Therefore, samples should be assigned to operators in a stratified-random manner. In the course of these studies, both operators also extracted individuals of the common nematode family Desmoscolecidae significantly less efficiently than other nematode families, a …


Hawai'i Wildlife Fund V. County Of Maui, Lowell J. Chandler Apr 2018

Hawai'i Wildlife Fund V. County Of Maui, Lowell J. Chandler

Public Land & Resources Law Review

In Hawai’i Wildlife Fund v. County of Maui, the Ninth Circuit held that the plain language of the Clean Water Act provides jurisdiction over indirect discharges of pollutants from a point source into groundwater that is shown to be connected to navigable waters. The court found that studies confirmed pollutants entering the Pacific Ocean were fairly traceable to the County of Maui’s sewage disposal wells. In affirming the district court’s ruling, the Ninth Circuit held that Maui County violated the Clean Water Act by discharging pollutants into a navigable water without the required permit. The court also concluded the …


Assessing Phytoplankton Nutritional Status And Potential Impact Of Wet Deposition In Seasonally Oligotrophic Waters Of The Mid-Atlantic Bight, P. N. Sedwick, P. W. Bernhardt, M. R. Mulholland, R. G. Najjar, L. M. Blumen, B. M. Sohst, C. Sookhdeo, Brittany Widner Apr 2018

Assessing Phytoplankton Nutritional Status And Potential Impact Of Wet Deposition In Seasonally Oligotrophic Waters Of The Mid-Atlantic Bight, P. N. Sedwick, P. W. Bernhardt, M. R. Mulholland, R. G. Najjar, L. M. Blumen, B. M. Sohst, C. Sookhdeo, Brittany Widner

OES Faculty Publications

To assess phytoplankton nutritional status in seasonally oligotrophic waters of the southern Mid-Atlantic Bight, and the potential for rain to stimulate primary production in this region during summer, shipboard bioassay experiments were performed using natural seawater and phytoplankton collected north and south of the Gulf Stream. Bioassay treatments comprised iron, nitrate, iron + nitrate, iron + nitrate + phosphate, and rainwater. Phytoplankton growth was inferred from changes in chlorophyll a, inorganic nitrogen, and carbon-13 uptake, relative to unamended control treatments. Results indicated the greatest growth stimulation by iron + nitrate + phosphate, intermediate growth stimulation by rainwater, modest growth …


Mesoscale Effects On Carbon Export: A Global Perspective, Cheryl S. Harrison, Matthew C. Long, Nicole S. Lovenduski, Jefferson K. Moore Apr 2018

Mesoscale Effects On Carbon Export: A Global Perspective, Cheryl S. Harrison, Matthew C. Long, Nicole S. Lovenduski, Jefferson K. Moore

School of Earth, Environmental, & Marine Sciences Faculty Publications

Carbon export from the surface to the deep ocean is a primary control on global carbon budgets and is mediated by plankton that are sensitive to physical forcing. Earth system models generally do not resolve ocean mesoscale circulation ((10–100) km), scales that strongly affect transport of nutrients and plankton. The role of mesoscale circulation in modulating export is evaluated by comparing global ocean simulations conducted at 1∘ and 0.1∘ horizontal resolution. Mesoscale resolution produces a small reduction in globally integrated export production (<2%); however, the impact on local export production can be large (±50%), with compensating effects in different ocean basins. With mesoscale resolution, improved representation of coastal jets block off-shelf transport, leading to lower export in regions where shelf-derived nutrients fuel production. Export is further reduced in these regions by resolution of mesoscale turbulence, which restricts the spatial area of production. Maximum mixed layer depths are narrower and deeper across the Subantarctic at higher resolution, driving locally stronger nutrient entrainment and enhanced summer export production. In energetic regions with seasonal blooms, such as the Subantarctic and North Pacific, internally generated mesoscale variability drives substantial interannual variation in local export production. These results suggest that biogeochemical tracer dynamics show different sensitivities to transport biases than temperature and salinity, which should be considered in the formulation and validation of physical parameterizations. Efforts to compare estimates of export production from observations and models should account for large variability in space and time expected for regions strongly affected by mesoscale circulation.


Interactive Effects Of Hypoxia And Pcb Co-Exposure On Expression Of Cyp1a And Its Potential Regulators In Atlantic Croaker Liver, Md. Saydur Rahman, Peter Thomas Apr 2018

Interactive Effects Of Hypoxia And Pcb Co-Exposure On Expression Of Cyp1a And Its Potential Regulators In Atlantic Croaker Liver, Md. Saydur Rahman, Peter Thomas

School of Earth, Environmental, & Marine Sciences Faculty Publications

Although marine and coastal environments which are contaminated with xenobiotic organic compounds often become hypoxic during the summer, the interactive effects of hypoxia and xenobiotic exposure on marine species such as teleost fishes remain poorly understood. The expression and activity of monooxygenase enzyme cytochrome P450-1A (CYP1A) in fishes are upregulated by exposure to polychlorinated biphenyls (PCBs), whereas they are down-regulated during hypoxia exposure. We investigated the interactive effects of hypoxia and PCB co-exposure on hepatic CYP1A expression in Atlantic croaker and on potential regulators of CYP1A. Croaker were exposed to hypoxia (1.7 mg/L dissolved oxygen), 3,3′,4,4′-tetrachlorobiphenyl (PCB 77, dose: 2 …


Legacy Contaminants In The Northern Gulf Of Mexico Shelf, Jessica N. Landry Mar 2018

Legacy Contaminants In The Northern Gulf Of Mexico Shelf, Jessica N. Landry

LSU Master's Theses

The Mississippi River watershed is the third largest in the world and drains from 31 states in the United States. Due to its route through the U.S., it passes through hundreds of EPA labeled Superfund sites as well as agricultural and suburban watersheds. These sites are known to have historical chemical contamination, and as a result chemicals can be transported by runoff down the Mississippi River into the Gulf of Mexico where their ultimate fate is unknown. Organochlorine chemicals are known to be persistent and are found in agricultural land as well as US EPA Superfund sites, especially DDT, PCBs, …


Effects Of Herbivores, Wave Exposure And Depth On Benthic Coral Communities Of The Easter Island Ecoregion, Erin E. Easton, Carlos F. Gaymer, Alan M. Friedlander, James J. Herlan Feb 2018

Effects Of Herbivores, Wave Exposure And Depth On Benthic Coral Communities Of The Easter Island Ecoregion, Erin E. Easton, Carlos F. Gaymer, Alan M. Friedlander, James J. Herlan

School of Earth, Environmental, & Marine Sciences Faculty Publications

The Easter Island ecoregion includes Rapa Nui (Easter Island; RN), with a human population of ~5600, and the uninhabited Salas y Gómez (SyG). Although the culture and terrestrial ecology of RN have been well studied, we know little about the marine environment of these islands, particularly the interplay among herbivores, algae, and corals, and how coral reef communities differ between islands, by wave energy exposure, and between depths. To address the potential roles of herbivores, wave-energy exposure, and depth on the sessile benthic communities, we examined herbivorous fish biomass, sea urchin (Diadema savignyi) density, and algal and coral …


Amphibians And Reptiles Of C. E. Miller Ranch And The Sierra Vieja, Chihuahuan Desert, Texas, Usa, Drew R. Davis, Travis J. Laduc Feb 2018

Amphibians And Reptiles Of C. E. Miller Ranch And The Sierra Vieja, Chihuahuan Desert, Texas, Usa, Drew R. Davis, Travis J. Laduc

School of Earth, Environmental, & Marine Sciences Faculty Publications

We report the occurrence of 50 species of amphibians and reptiles recently collected on C. E. Miller Ranch and the Sierra Vieja in the Chihuahuan Desert of Texas, USA and describe their perceived distribution and abundance across various habitat associations of the region. Our recent surveys follow intense, historic sampling of amphibians and reptiles from this region in 1948. Of the 50 species detected in recent surveys, six were not collected in 1948 and an additional three species documented in 1948 have yet to be detected in a 14-year period of recent surveys. Combining data from both historic and recent …


Preparing For A Northwest Passage: A Workshop On The Role Of New England In Navigating The New Arctic, Katharine A. Duderstadt, Catherine M. Ashcraft, Jennifer F. Brewer, Elizabeth Burakowski, Jaed M. Coffin, Jack E. Dibb, Lawrence C. Hamilton, Nancy E. Kinner, Larry A. Mayer, Jennifer L. Miksis-Olds, Joseph Salisbury, Kerri D. Seger, Ruth K. Varner, Cameron P. Wake Jan 2018

Preparing For A Northwest Passage: A Workshop On The Role Of New England In Navigating The New Arctic, Katharine A. Duderstadt, Catherine M. Ashcraft, Jennifer F. Brewer, Elizabeth Burakowski, Jaed M. Coffin, Jack E. Dibb, Lawrence C. Hamilton, Nancy E. Kinner, Larry A. Mayer, Jennifer L. Miksis-Olds, Joseph Salisbury, Kerri D. Seger, Ruth K. Varner, Cameron P. Wake

All Materials

Preparing for a Northwest Passage: A Workshop on the Role of New England in Navigating the New Arctic (March 25 - 27, 2018 -- The University of New Hampshire) paired two of NSF's 10 Big Ideas: Navigating the New Arctic and Growing Convergence Research at NSF. During this event, participants assessed economic, environmental, and social impacts of Arctic change on New England and established convergence research initiatives to prepare for, adapt to, and respond to these effects. Shipping routes through an ice-free Northwest Passage in combination with modifications to ocean circulation and regional climate patterns linked to Arctic ice melt …


Composition Of Dissolved Organic Matter In Pore Waters Of Anoxic Marine Sediments Analyzed By 1h Nuclear Magnetic Resonance Spectroscopy, Christina A. Fox, Hussain A. Abdulla, David J. Burdige, James P. Lewicki, Tomoko Komada Jan 2018

Composition Of Dissolved Organic Matter In Pore Waters Of Anoxic Marine Sediments Analyzed By 1h Nuclear Magnetic Resonance Spectroscopy, Christina A. Fox, Hussain A. Abdulla, David J. Burdige, James P. Lewicki, Tomoko Komada

OES Faculty Publications

Marine sediments are globally significant sources of dissolved organic matter (DOM) to the oceans, but the biogeochemical role of pore-water DOM in the benthic and marine carbon cycles remains unclear due to a lack of understanding about the molecular composition of DOM. To help fill this knowledge gap, we used 1H nuclear magnetic resonance (NMR) spectroscopy to examine depth variability in the composition of pore-water DOM in anoxic sediments of Santa Barbara Basin, California Borderland. Proton detected spectra were acquired on whole samples without pre-concentration to avoid preclusion of any DOM components from the analytical window. Broad unresolved resonance (operationally …