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Full-Text Articles in Physical Sciences and Mathematics

Peak Chlorophyll A Concentrations In The Lower Mississippi River From 1997 To 2018, R. Eugene Turner, Charles S. Milan, Erick M. Swenson, James M. Lee Mar 2022

Peak Chlorophyll A Concentrations In The Lower Mississippi River From 1997 To 2018, R. Eugene Turner, Charles S. Milan, Erick M. Swenson, James M. Lee

Faculty Publications

Large and turbid rivers have varying temperatures, light conditions, nutrient availability, and nutrient ratios that may affect phytoplankton communities and occur within a changing world of point and nonpoint source nutrient loadings. We investigated how these physical and chemical factors affect Chlorophyll a (Chl a) concentrations in the Mississippi River, the largest river in North America, by sampling 878 times from February 1997 to December 2018 near its terminus at Baton Rouge, Louisiana. We hypothesized that nutrient concentrations and ratios were significant factors limiting phytoplankton biomass accumulations in this turbid river. The Chl a concentrations were in the "poor" water …


Connecting The Dots: Transmission Of Stony Coral Tissue Loss Disease From The Marquesas To The Dry Tortugas, Thomas Dobbelaere, Daniel M. Holstein, Erinn M. Muller, Lewis J. Gramer, Lucas Mceachron, Sara D. Williams, Emmanuel Hanert Feb 2022

Connecting The Dots: Transmission Of Stony Coral Tissue Loss Disease From The Marquesas To The Dry Tortugas, Thomas Dobbelaere, Daniel M. Holstein, Erinn M. Muller, Lewis J. Gramer, Lucas Mceachron, Sara D. Williams, Emmanuel Hanert

Faculty Publications

For the last 7 years, Florida's Coral Reef (FCR) has suffered from widespread and severe coral loss caused by stony coral tissue loss disease (SCTLD). First observed off the coast of Miami-Dade county in 2014, the outbreak has since spread throughout the entirety of FCR and some areas of the Caribbean. However, the propagation of the disease through FCR seemed to slow down when it reached the western end of the Marquesas in August 2020. Despite being present about 30 km (similar to 20 miles) from the Dry Tortugas (DRTO), SCTLD was not reported in this area before May 2021. …


Testing Xrf Identification Of Marine Washover Sediment Beds In A Coastal Lake In Southeastern Texas, Usa, Harry F. L. Williams, Chelsea E. Beaubouef, Kam-Biu Liu, Nicholas Culligan, Lance Riedlinger Jan 2022

Testing Xrf Identification Of Marine Washover Sediment Beds In A Coastal Lake In Southeastern Texas, Usa, Harry F. L. Williams, Chelsea E. Beaubouef, Kam-Biu Liu, Nicholas Culligan, Lance Riedlinger

Faculty Publications

This study tests the ability of a novel approach to identifying washover beds in coastal lakes. Combined X-Ray Fluorescence (XRF) and cluster analysis was used to identify hurricane washover beds in sediment cores from Clam Lake on the McFaddin National Wildlife Refuge in southeastern Texas. The lake is known to contain washover beds from recent hurricanes, but the washover sediment has similar microfossil, loss-on-ignition and textural characteristics to non-washover sediment and is not readily distinguishable. Sediment cores taken from marshes surrounding the lake do contain visually-recognizable sandy washover beds of Hurricanes Ike, Rita, Carla and Audrey. XRF analysis of these …


Ecosytem Services: Delivering Decision-Making For Salt Marshes, Philine S. E. Zu Ermgassen, Ronald Baker, Michael W. Beck, Kate Dodds, Sophus O. S. E. Zu Ermgassen, Debbrota Mallick, Matthew D. Taylor, R. Eugene Turner May 2021

Ecosytem Services: Delivering Decision-Making For Salt Marshes, Philine S. E. Zu Ermgassen, Ronald Baker, Michael W. Beck, Kate Dodds, Sophus O. S. E. Zu Ermgassen, Debbrota Mallick, Matthew D. Taylor, R. Eugene Turner

Faculty Publications

No abstract provided.


Tidal And Storm Impacts On Hydrodynamics And Sediment Dynamics In An Energetic Ebb Tidal Delta, Kehui Xu, P. Ansley Wren, Yanxia Ma Oct 2020

Tidal And Storm Impacts On Hydrodynamics And Sediment Dynamics In An Energetic Ebb Tidal Delta, Kehui Xu, P. Ansley Wren, Yanxia Ma

Faculty Publications

Bottom-mounted instrumentation was deployed at two sites on a large sandy shoal of an ebb tidal delta offshore of the Port Royal Sound of South Carolina of USA to collect hydrodynamics and sediment dynamics data. One site ("borrow site") was 2 km offshore in a dredge pit for nearby beach nourishment and the other site ("reference site") was 10 km offshore. In situ time-series data were collected during two periods after the dredging: 15 March-12 June (spring) and 18 August-18 November (fall) of 2012. Data at the reference site indicated active migrating bedforms from centimeters to decimeters tall, and sediment …


Fish Assemblages Associated With Artificial Reefs Assessed Using Multiple Gear Types In The Northwest Gulf Of Mexico, Jeffrey D. Plumlee, Kaylan M. Dance, Michael A. Dance, Hay R. Rooker, Thomas C. Tinhan, J. Brooke Shipley, R. J. David Wells Oct 2020

Fish Assemblages Associated With Artificial Reefs Assessed Using Multiple Gear Types In The Northwest Gulf Of Mexico, Jeffrey D. Plumlee, Kaylan M. Dance, Michael A. Dance, Hay R. Rooker, Thomas C. Tinhan, J. Brooke Shipley, R. J. David Wells

Faculty Publications

Quantitative surveys of fishes associated with artificial reefs in the northwest Gulf of Mexico were conducted over a 4-yr period (2014-2017). Artificial reefs surveyed were comprised of three types: concrete structures, rig jackets, and decommissioned ships. All reefs were surveyed using vertical long line ( VLL), fish traps, and Adaptive Resolution Imaging Sonar (ARIS 1800). Mean fish abundance did not significantly differ using VLL [1.7 ind set(-1) (SD 2.2)] among the three reef types. However, relative abundance among all fishes collected was significantly highest on rig reefs using traps [6.2 ind soak(-1) (SD 3.8)], while results from sonar surveys indicated …


The Life And Death And Consequences Of Canals And Spoil Banks In Salt Marshes, R. Eugene Turner, Erick M. Swenson Sep 2020

The Life And Death And Consequences Of Canals And Spoil Banks In Salt Marshes, R. Eugene Turner, Erick M. Swenson

Faculty Publications

We describe the consequence and demise of levees (spoil banks) built from dredging canals in Louisiana salt marshes using morphometric measurements made over 30 years, soil collections on the spoil bank and in the salt marshes behind, and complementary observations from other areas. These measurements were used to determine the temporal bounds of how long spoil banks last and if salt marsh soils remaining in salt marshes are affected. If the rates of changes in spoil bank morphology continue, then the estimated life time of the shrub-tree vegetation at a representative spoil bank is 81 years, the spoil bank width …


Optical Properties Using Adaptive Selection Of Nir/Swir Reflectance Correction And Quasi-Analytic Algorithms For The Modis-Aqua In Estuarine-Ocean Continuum: Application To The Northern Gulf Of Mexico, Ishan D. Joshi, Eurico J. D'Sa Sep 2020

Optical Properties Using Adaptive Selection Of Nir/Swir Reflectance Correction And Quasi-Analytic Algorithms For The Modis-Aqua In Estuarine-Ocean Continuum: Application To The Northern Gulf Of Mexico, Ishan D. Joshi, Eurico J. D'Sa

Faculty Publications

An adaptive selection of the near/shortwave infrared (NIR/SWIR) reflectance correction and the quasi-analytic algorithms (QAAs) is proposed for the Moderate Resolution Imaging Spectroradiometer (MODIS-Aqua) to utilize the strengths of different correction algorithms and QAAs in a single satellite scene with water types ranging from turbid coastal to clear open ocean waters. A blended satellite product is generated by merging three atmospheric-correction algorithms(AD-ATCOR): 1) iterative NIR correction; 2) management unit of the north sea mathematical models (MUMM); and 3) SWIR, using a spectral threshold-based selection for different water types. The validation analysis of a blended remote sensing reflectance product showed overall …


Tropical Cyclone Landfall Frequency And Large-Scale Environmental Impacts Along Karstic Coastal Regions (Yucatan Peninsula, Mexico), Victor H. Rivera-Monroy, Luis M. Farfan, Luis Brito-Castillo, Jorge Cortes-Ramos, Eduardo Gonzalez-Rodriguez, Eurico D'Sa, Jorge I. Euan-Avila Sep 2020

Tropical Cyclone Landfall Frequency And Large-Scale Environmental Impacts Along Karstic Coastal Regions (Yucatan Peninsula, Mexico), Victor H. Rivera-Monroy, Luis M. Farfan, Luis Brito-Castillo, Jorge Cortes-Ramos, Eduardo Gonzalez-Rodriguez, Eurico D'Sa, Jorge I. Euan-Avila

Faculty Publications

Tropical cyclones (TCs) are natural systems that develop over ocean basins and are key components of the atmospheric activity during the warm season. However, there are still knowledge gaps about the combined positive and negative TC impacts on the structure and function of coastal socio-ecosystems. Using remote sensing tools, we analyzed the frequency, trajectory, and intensity of 1894 TCs from 1851-2019 to identify vulnerable "hotspots" across the Yucatan Peninsula (YP), Mexico. A total of 151 events hit the YP, with 96% of landings on the eastern coast. We focused on three major hurricanes (Emily and Wilma, 2005; Dean, 2007) and …


Gulf Of Mexico Hypoxia: Past, Present, And Future, Nancy N. Rabalais, R. Eugene Turner Nov 2019

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 …


Age And Growth Of Hardhead Catfish And Gafftopsail Catfish In Coastal Louisiana, Usa, Shane Flinn, Stephen Midway Oct 2019

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 …


The Tensile Root Strength Of Spartina Patens Varies With Soil Texture And Atrazine Concentration, Lauris O. Hollis, R. Eugene Turner Sep 2019

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 Aug 2019

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 …


The Effects Of Oil On Blue Crab And Periwinkle Snail Interactions: A Mesocosm Study, Elizabeth M. Robinson, Nancy N. Rabalais Aug 2019

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). …


Wide-Ranging Temporal Variation In Transoceanic Movement And Population Mixing Of Bluefin Tuna In The North Atlantic Ocean, Michael A. Dance Jul 2019

Wide-Ranging Temporal Variation In Transoceanic Movement And Population Mixing Of Bluefin Tuna In The North Atlantic Ocean, Michael A. Dance

Faculty Publications

Uncertainty regarding the movement and population exchange of Atlantic bluefin tuna (Thunnus thynnus) from the two primary spawning areas (Gulf of Mexico, Mediterranean Sea) is increasingly implicated as a major impediment for the conservation of this species. Here, two mixture methods were applied to natural chemical markers (delta O-18 and delta C-13) in otoliths (ear stones) to comprehensively investigate the nature and degree of transoceanic movement and mixing of eastern and western populations in several areas of the North Atlantic Ocean that potentially represent mixing hotspots. Areas investigated occurred on both sides of the 45 degrees W management boundary as …


Spatial Variations In Chlorophyll A, C, N, And P In A Louisiana Estuary From 1994 To 2016, R. Eugene Turner, Erick M. Swenson, Charles S. Milan, James M. Lee May 2019

Spatial Variations In Chlorophyll A, C, N, And P In A Louisiana Estuary From 1994 To 2016, R. Eugene Turner, Erick M. Swenson, Charles S. Milan, James M. Lee

Faculty Publications

Intense sampling of an estuary can reveal relative spatial changes that are significant irrespective of whether or not the estuary is eutrophic, micro- or meso-tidal, disturbed, or restored. This waterscape' perspective is analogous to a landscape perspective. We collected monthly water samples in the Barataria Basin watershed from 1994 to 2016 at 37 stations along a 129km transect from 1km offshore to a freshwater stream. The average Chlorophyll a (Chl) concentration from 267 trips was supported from both nitrogen-fixing cyanobacteria in a freshwater lake and partially from nutrients in seaward sources. Estuarine salinity was correlated with the discharge of the …


An Objective Procedure For Delineating The Circumpolar Vortex, Nazla Bushra, Robert V. Rohli May 2019

An Objective Procedure For Delineating The Circumpolar Vortex, Nazla Bushra, Robert V. Rohli

Faculty Publications

The broad-scale, steering atmospheric circulation in the Northern Hemisphere, represented by the tropospheric circumpolar vortex (CPV), is an important driver of environmental processes. The area and circularity of the CPV are analyzed hereby delineating the leading edge of the CPV at the steepest 500-hPa geopotential height gradient globally. The daily CPV area and circularity were aggregated to monthly averages for contrast with measurements identified in previous research for the overlapping period of record (1979-2001). Accuracy of representation of the CPV is assessed through correlations to air-sea teleconnections known to be associated with broad-scale, extratropical steering circulation. Correlation to monthly teleconnection …


In Situ Geochemistry Of Middle Ordovician Dolomites Of The Upper Mississippi Valley, Achim D. Herrmann Feb 2019

In Situ Geochemistry Of Middle Ordovician Dolomites Of The Upper Mississippi Valley, Achim D. Herrmann

Faculty Publications

The dolomitization and diagenetic history of Ordovician carbonates of southern Wisconsin is complex. Previous studies attributed dolomitization to various diagenetic factors and environments. In this study, high-resolution, in situ laser ablation inductively coupled mass spectrometry analysis of rare earth element patterns of dolomite was used to assess the diagenetic fluids responsible for dolomitization of the Ordovician Decorah Formation. Integrated geochemical data and petrographic evidence suggest that the dolostones are formed in two different diagenetic realms: shallow burial and hydrothermal. Shallow burial dolomites exhibit three distinct rare earth element patterns. Dolomite from the middle portion of the Guttenberg Member exhibits light …


Effects Of Shoal Margin Collapses On The Morphodynamics Of A Sandy Estuary, M. R. Hiatt Jan 2019

Effects Of Shoal Margin Collapses On The Morphodynamics Of A Sandy Estuary, M. R. Hiatt

Faculty Publications

Shoal margin collapses of several million cubic meters have occurred in the Western Scheldt estuary, the Netherlands, on average five times a year over the last decades. While these collapses involve significant volumes of material, their effect on the channel-shoal morphology is unknown. We hypothesize that collapses dynamicize the channel-shoal interactions, which could impact the ecological functioning, flood safety, and navigation in the estuary. The objective is to investigate how locations, probability, type, and volume of shoal margin collapse affect the channel-shoal dynamics. We implemented an empirically validated parameterization for shoal margin collapses and tested its effect on simulated estuary …


Dinoflagellate Cysts Track Eutrophication In The Northern Gulf Of Mexico, Andrea M. Price, Melissa M. Baustian, R. Eugene Turner, Nancy N. Rabalais, Gail L. Chmura Dec 2017

Dinoflagellate Cysts Track Eutrophication In The Northern Gulf Of Mexico, Andrea M. Price, Melissa M. Baustian, R. Eugene Turner, Nancy N. Rabalais, Gail L. Chmura

Faculty Publications

We examined organic-walled dinoflagellate cysts from one 210Pb-dated sediment core and 39 surface sediment samples from the northern Gulf of Mexico to determine the relationship between nutrient enrichment and cyst assemblages in this region characterized by oxygen deficiency. The core spans from 1962 to 1997 and its sampling location is directly influenced by the Mississippi River plume. Surface sediments were collected in 2006, 2007, 2008, and 2014 and represent approximately 1 to 4 years of accumulation. A total of 57 cyst taxa were recorded, and four heterotrophic taxa in particular were found to increase in the top section (1986–1997) of …


The Changshu Declaration On Wetlands, R. Eugene Turner, Jos T. A. Verhoeven, Ania Grobicki, Jenny Davis, Shuqing An Sep 2016

The Changshu Declaration On Wetlands, R. Eugene Turner, Jos T. A. Verhoeven, Ania Grobicki, Jenny Davis, Shuqing An

Faculty Publications

No abstract provided.


Influence Of The Mississippi River On Pseudo-Nitzschia Spp. Abundance And Toxicity In Louisiana Coastal Waters, Sibel Bargu, Melissa M. Baustian, Nancy N. Rabalais, Ross Del Rio, Benjamin Von Korff, R. Eugene Turner Mar 2016

Influence Of The Mississippi River On Pseudo-Nitzschia Spp. Abundance And Toxicity In Louisiana Coastal Waters, Sibel Bargu, Melissa M. Baustian, Nancy N. Rabalais, Ross Del Rio, Benjamin Von Korff, R. Eugene Turner

Faculty Publications

The presence of domoic acid (DA) toxin from multiple species of Pseudo-nitzschia is a concern in the highly productive food webs of the northern 1,* 2,3 2 1 1,4 1 1 2 3 4 Gulf of Mexico. We documented the Pseudo-­nitzschia presence, abundance, blooms, and toxicity over 3 years along a transect ∼100 km west of the Mississippi River Delta on the continental shelf. Pseudo-nitzschia were present throughout the year and occurred in high abundances (>10 cells l ) in the early spring months during high Mississippi River (MSR) flow (∼20,000 m s ) but were most abundant ( …


Size-Dependent Top-Down Control On Phytoplankton Growth By Microzooplankton In Eutrophic Lakes, Wai Hing Wong, Nancy N. Rabalais, R. Eugene Turner Jan 2016

Size-Dependent Top-Down Control On Phytoplankton Growth By Microzooplankton In Eutrophic Lakes, Wai Hing Wong, Nancy N. Rabalais, R. Eugene Turner

Faculty Publications

We hypothesized that the grazing on phytoplankton by the microzooplankton community is size-dependent and, therefore, the top-down control on phytoplankton by microzooplankton community could be one possible mechanism explaining why small phytoplankton become less abundant than large phytoplankton in eutrophic waters. We tested this hypothesis using the dilution method to measure microzooplankton grazing rates and phytoplankton growth rates in the eutrophic waters of the Barataria estuary, southeastern Louisiana. Microzooplankton grazing rates on the slower growing, small phytoplankton (\5 lm) were higher than on the large phytoplankton ([20 lm) which had relatively faster growth rates. The proportional loss of the small, …


Effects Of Oil-Contaminated Sediments On Submerged Vegetation: An Experimental Assessment Of Ruppia Maritima, Charles W. Martin, Lauris O. Hollis, R. Eugene Turner Oct 2015

Effects Of Oil-Contaminated Sediments On Submerged Vegetation: An Experimental Assessment Of Ruppia Maritima, Charles W. Martin, Lauris O. Hollis, R. Eugene Turner

Faculty Publications

Oil spills threaten the productivity of ecosystems through the degradation of coastal flora and the ecosystem services these plants provide. While lab and field investigations have quantified the response of numerous species of emergent vegetation to oil, the effects on submerged vegetation remain uncertain. Here, we discuss the implications of oil exposure for Ruppia maritima, one of the most common species of submerged vegetation found in the region affected by the recent Deepwater Horizon oil spill. We grew R. maritima in a range of manipulated sediment oil concentrations: 0, 0.26, 0.53, and 1.05 mL oil /L tank volume, and tracked …


The Global Sustainability Transition: It Is More Than Changing Light Bulbs, Michael P. Weinstein, R. Eugene Turner, Carles Ibanez Jan 2013

The Global Sustainability Transition: It Is More Than Changing Light Bulbs, Michael P. Weinstein, R. Eugene Turner, Carles Ibanez

Faculty Publications

Current policies and norms to reconcile human demands for resources with the Earth’s ability to supply them have resulted in practices that mainly treat the symptoms of unsustainability rather than their underlying causes. Moreover, the increase in our knowledge about humankind’s role in ecosystems is not keeping pace with our understanding of the consequences of our actions, resulting in a deepening inability to address sustainability issues. The extreme complexity and intricate workings of the world require the expansion of our mental models in a systems-thinking framework if we are to realize a sustainable place for humans in it. The challenge …


Carbon Sequestration And Sediment Accretion In San Francisco Bay Tidal Wetlands, John C. Callaway, Evyan L. Borgnis, R. Eugene Turner, Charles S. Milan Jun 2012

Carbon Sequestration And Sediment Accretion In San Francisco Bay Tidal Wetlands, John C. Callaway, Evyan L. Borgnis, R. Eugene Turner, Charles S. Milan

Faculty Publications

Tidal wetlands play an important role with respect to climate change because of both their sensitivity to sea-level rise and their ability to sequester carbon dioxide from the atmosphere. Policy-based interest in carbon sequestration has increased recently, and wetland restoration projects have potential for carbon credits through soil carbon sequestration. We measured sediment accretion, mineral and organic matter accumulation, and carbon sequestration rates using 137Cs and 210Pb downcore distributions at six natural tidal wetlands in the San Francisco Bay Estuary. The accretion rates were, in general, 0.2–0.5 cm year−1, indicating that local wetlands are keeping pace with recent rates of …


Sustainability: More About The Toolmaker Than The Tools, R. Eugene Turner Apr 2012

Sustainability: More About The Toolmaker Than The Tools, R. Eugene Turner

Faculty Publications

A sustainable system is not necessarily a high-quality one, but it could be. We could, for example, “survive” on the desperate edge, as the remnants in a self-fouled and deteriorating environment. Why won’t a future sustainable system be just another industrial model of mass efficiency and throughput? Perhaps the incompatible outcomes are a choice between the sometimes nearly invisible civilizing aspects of culture nurturing respect, equality, and cooperation on one hand, and the greed and self-indulgences undermining social tolerance, empathy, and cooperation that ends up promoting violence and dehumanization. The human heritage is subtle, indestructible, and worth nurturing if we …


A Once And Future Gulf Of Mexico Ecosystem: Restoration Recommendations Of An Expert Working Group, Charles H. Peterson, Felicia C. Coleman, Jeremy B. C. Jackson, R. Eugene Turner, Gilbert T. Rowe, Richard T. Barber, Karen A. Bjorndal, Robert S. Carney, Robert K. Cowen, Jonathan M. Hoekstra, James T. Hollibaugh, Shirley B. Laska, Richard A. Luettich, Jr., Craig W. Osenberg, Stephen E. Roady, Stanley Senner, John M. Teal, Ping Wong Sep 2011

A Once And Future Gulf Of Mexico Ecosystem: Restoration Recommendations Of An Expert Working Group, Charles H. Peterson, Felicia C. Coleman, Jeremy B. C. Jackson, R. Eugene Turner, Gilbert T. Rowe, Richard T. Barber, Karen A. Bjorndal, Robert S. Carney, Robert K. Cowen, Jonathan M. Hoekstra, James T. Hollibaugh, Shirley B. Laska, Richard A. Luettich, Jr., Craig W. Osenberg, Stephen E. Roady, Stanley Senner, John M. Teal, Ping Wong

Faculty Publications

The Deepwater Horizon (DWH) well blowout released more petroleum hydrocarbons into the marine environment than any previous U.S. oil spill (4.9 million barrels), fouling marine life, damaging deep sea and shoreline habitats and causing closures of economically valuable fisheries in the Gulf of Mexico. A suite of pollutants—liquid and gaseous petroleum compounds plus chemical dispersants—poured into ecosystems that had already been stressed by overfishing, development and global climate change. Beyond the direct effects that were captured in dramatic photographs of oiled birds in the media, it is likely that there are subtle, delayed, indirect and potentially synergistic impacts of these …


Beneath The Salt Marsh Canopy: Loss Of Soil Strength With Increasing Nutrient Loads, R. Eugene Turner Sep 2010

Beneath The Salt Marsh Canopy: Loss Of Soil Strength With Increasing Nutrient Loads, R. Eugene Turner

Faculty Publications

Although the broadly observed increase in nutrient loading rates to coastal waters in the last 100 years may increase aboveground biomass, it also tends to increase soil metabolism and lower root and rhizome biomass—responses that can compromise soil strength. Fourteen different multiyear field combinations of nutrient amendments to salt marshes were made to determine the relationship between soil strength and various nitrogen, phosphorus, and nitrogen+phosphorus loadings. There was a proportional decline in soil strength that reached 35% in the 60- to 100-cm soil layer at the highest loadings and did not level off. These loading rates are equivalent to those …


Abundance And Ecological Significance Of The Clam Rangia Cuneata (Sowerby, 1831) In The Upper Barataria Estuary (Louisiana, Usa), Wai Hing Wong, Nancy N. Rabalais, R. Eugene Turner Jun 2010

Abundance And Ecological Significance Of The Clam Rangia Cuneata (Sowerby, 1831) In The Upper Barataria Estuary (Louisiana, Usa), Wai Hing Wong, Nancy N. Rabalais, R. Eugene Turner

Faculty Publications

We proposed that Rangia cuneata (Sowerby, 1831) is an important estuarine bivalve with ecological significance in three coastal lakes in Barataria Bay, Gulf of Mexico—Lake Cataouatche, Lake Salvador and Lac des Allemands. Our goals were to determine the abundance and distribution of Rangia in these lakes and to measure clearance times to elucidate its potential impacts on phytoplankton communities. The estimated average densities of R. cuneata in Lake Cataouatche, Lake Salvador, and Lac des Allemands were 63, 157, and 107 individuals m−2, respectively, which is 30% lower than that observed in nearby Lake Pontchartrain. The size of clams in Lake …