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Spatial Distribution of Anthropogenic Environmental Hazards in the Louisiana Coastal Zone: Implications for Ecosystem RestorationKroninger, Melissa Ann 13 November 2006 (has links)
The purpose of this project was to assess the spatial distribution of anthropogenic environmental hazards in the Louisiana coastal zone and implications of those hazards for coastal resources and restoration efforts. Several state and federal environmental databases publicly available on the internet were selected for inclusion in this study. The hazard sites were mapped in a Geographic Information System by geocoding addresses obtained from the databases. Sites with unmatched addresses were mapped to zip code centroid. Hazard types in databases lacking spatial data at the address level were totaled and mapped by parish. Buffers were created at 1, 2, 3, 4, and 5 mile radii of hazard sites to assess the proximity of state and federal coastal restoration projects and the distribution of Land Use and Land Cover types within the buffers. The federal databases were more comprehensive than the state databases, but the compatibility among all of the databases varied. The most comprehensive database was the Toxics Release Inventory (TRI) which, unlike any of the other databases, included chemical names and quantities releases as well as geographic coordinates. The TRI did not contain any toxicity data; therefore outside sources must be consulted to use the data for risk assessment. In general, hazard sites were distributed along major commerce corridors, especially waterways, and near populated areas. Because these hazard types appear to follow human settlement patterns, the cumulative risk posed by these facilities will continue to grow in concert with the growing coastal population. The negative externalities associated with the needs of a growing coastal population stand in stark contrast to coastal restoration efforts in Louisiana and, if left unchecked, may stand as a roadblock to the success of those efforts.
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The Impact of Hypoxia on Mercury Methylation in Bottom Sediment of Northern Gulf of MexicoTan, Mei Huey 16 November 2006 (has links)
Widespread concern has developed about high mercury content in fish in the Gulf of Mexico and adjacent estuaries and bays. Among the areas implicated as possible sources of the mercury that moves up the food chain from the methylmercury formed in sediments and anoxic waters is the seasonal hypoxic zone in the northern Gulf. This research was designed to determine if methylmercury formation is stimulated by the anaerobic sediment conditions accompanying the onset of summer hypoxia in the Gulf. Both field and laboratory studies were carried out. For the field study sediment samples were collected at three stations (i.e. C4, C6B and C8) along hypoxic transect C established by Nancy Rabalais at a monthly interval from April 05 to April 06 for total and methyl mercury analyses. In-situ concentrations of dissolved oxygen, temperature and salinity of bottom waters were measured using a hydro-lab. For the laboratory study the effects of anaerobic conditions and organic matter contents on methylation rate were investigated using sediment-water columns. The most probable number (MPN) of the sulfate reducing bacteria in sediments was enumerated to obtain insights into the microbial mechanism of mercury methylation. Seasonal variations in methylmercury concentrations were observed at three stations with the peak in spring 2005. This seasonal pattern might be attributed to the seasonal inputs of freshwater from the Mississippi river into the gulf. Annual average concentrations of methyl mercury were 0.31, 0.47 and 0.12 ug/kg at C4, C6B and C8, respectively. Annual averages of total mercury concentrations were 37.79, 41.06 and 11.02 ug/kg for C4, C6B and C8, respectively. Sediment texture may explain the spatial variations of methyl and total mercury among the stations. Statistical analyses indicate that the dissolved oxygen (P<0.0001), temperature (P=0.03) and sediment texture (P=0.001) significantly affected the methyl mercury concentration. The laboratory study indicates that organic matter was an important factor in controlling the rate of mercury methylation.
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Laboratory Evaluation of Dunaliella tertiolecta as a Candidate Algal Species for Tertiary Wastewater Treatment of Nitrogen and Phosphorus-Laden Effluents Impacting Marine EnvironmentsBelle, Ashley Juanika 27 March 2007 (has links)
Dunaliella tertiolecta was evaluated to determine the effectiveness of utilizing the algal species to reduce the nutrient load of saline wastewater during tertiary treatment. Nutrient uptake studies performed using f/2-Si medium illustrated that Dunaliella tertiolecta favored phosphate uptake over nitrate-nitrogen. Over a 7-day observational period, total phosphorus concentration was reduced by over 97% and the kinetic rate of uptake observed was approximately 0.5 - 1 mg/L/day. Daily nitrate-nitrogen concentrations were highly variable and a model could not be determined to predict uptake behavior. In heavily concentrated nutrient loads, the algae still favored phosphate uptake. However as the nutrient load increased from 4X to 32X, the percent reduction in total phosphorus concentration decreased linearly; biomass was reduced by over 20% for cell cultures containing the heaviest concentrated nutrient loads.
Since immobilized microbe bioreactor treatment was not successful in significantly reducing nitrate-nitrogen and phosphate present in the landfill leachate, Dunaliella tertiolecta was used in simulated high-rate algal ponds to assimilate the nutrients. Simulated HRAP treatment greatly reduced (p-value < 0.05) the nitrogen-ammonia nutrient load in both leachate samples; the kinetic rates of uptake averaged 1.61 mg/L/day during week 1 and 0.48 mg/L/day during week 2 for the collection pond leachate. The kinetic uptake rates averaged 0.61 mg/L/day and 0.12 mg/L/day during week 1 and week 2 respectively for the holding tank leachate.
However, since Dunaliella tertiolecta favored nitrogen uptake in the form of nitrogen-ammonia, nitrate-nitrogen uptake was significantly (p-value > 0.05) suppressed until nitrogen-ammonia concentrations were lowered. On average, the kinetic uptake rate observed for nitrate-nitrogen was 0.04 mg/L/day. Phosphate uptake also appeared to be suppressed by the presence of nitrogen-ammonia; total phosphorus concentrations increased linearly over the 14-days, but during week 2 the increase in concentration began to plateau as nitrogen-ammonia uptake decreased. Since Dunaliella tertiolecta had the ability to assimilate nutrients from heavily concentrated environments, it is likely that the marine algal species would be an ideal candidate for tertiary treatment of saline wastewaters when nitrogen-ammonia is present at extreme concentrations; in order to see significant overall reductions at such concentrations, the retention time would have to exceed 14-days.
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Environmental Factors Influencing the Siting of Temporary Housing in Orleans ParishChandler, Philip J. 13 April 2007 (has links)
The disaster in New Orleans due to Hurricane Katrina showcased the city's many environmental problems. The industrial history of the city, subsidence of the city causing it to be below sea-level, and the fact that the city is protected by levees and pumps were critical elements of the disaster and played a large role in the emergency response. The disaster led to an enormous emergency response by many entities, but the Federal Emergency Management Agency (FEMA) has the lead in these actions. In response to the large number of homes being flooded and unlivable in Orleans Parish, FEMA implemented its temporary housing program. This program's goal is to house the largest number of people in the shortest period of time. The process in response to Hurricane Katrina involved the placement of manufactured housing on homeowners' lawns, in commercial trailer parks, and on properties leased by FEMA. The parks that FEMA built for manufactured housing are like any other federal action and must comply with the National Environmental Policy Act.
This research seeks to outline FEMA's process of implementing temporary housing and to identify the environmental factors and demographic factors that may have influenced the siting of temporary housing group sites in Orleans Parish after Hurricane Katrina. This research uses data on temporary housing sites considered for use and sites that were constructed obtained from FEMA via Freedom of Information Act Request and U.S. Census data to identify which factors were essential to the successful siting or unsuccessful siting of temporary housing parks.
The results indicate positive correlations with sites being constructed and being in historic districts and passing the FEMA environmental review. The results also indicate negative correlations between sites being constructed and having a Pre-Katrina hazardous material issue as well as sites being of residential land-use. The difference of means analysis between sites built and not built also identified differences between the number of proposed units and the size of the proposed site. The sites not built had larger means of the proposed number units and the size of the proposed site.
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Evaluation of Allochthonous and Autochthonous Microbial Populations in the In-situ Remediation of Weathered Oil in a Coastal Freshwater HabitatSchmidt, Kyle Alan 08 June 2007 (has links)
Use of bioremedial technologies has gained popularity in recent decades for application at oil spill sites. While much research has been done on specific case studies along marine shores, such as with the spill of the Exxon Valdez, there still remain questions as to the advantage of active biological treatment vs. natural attenuation in freshwater environments. To examine this question, a comparative study of allochthonous and autochthonous microbial communities ability to degrade weathered oil residuals was implemented at the CITGO Petroleum Refinery in Lake Charles, Louisiana following a spill of approximately 40,000 barrels of slop oil on June 19th, 2006 into a freshwater drainage canal and wetland area.
Three treatments were tested including bioaugmentation, or the addition of a cultured allochthonous microbial community, biostimulation, utilizing the addition of nutrient amendments to aid the growth of autochthonous microbial populations, and finally an experimental control or a natural attenuation treatment. After completion of treatment applications for 74 days, sampling and analysis at three sampling intervals (0, 43, and 74 days), and statistical analysis performed in two manners (including day 0 data as sampling points, and correcting for initial variability with day 0 data) research has shown that there was no statistical difference between the effects of either active treatment type and that of the experimental control.
Biological remedial activity of a freshwater spill site in a warm climate was observed to be more influenced by the natural environment and climate conditions than by that of anthropogenic inputs such as nutrient supplement or selective allochthonous bacterial communities. Furthermore, autochthonous microbial communities exhibited similar bacterial activity as well as the ability to successfully reduce petroleum hydrocarbon concentrations within the freshwater canal to below that of Louisiana Department of Environmental Quality RECAP screening levels for continued industrial use based on oil Total Petroleum Hydrocarbon fraction analysis (LDEQ, 2003).
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Providing the Best of Both Worlds: Balancing Conservation and Recreation in a System of Protected Areas in TexasSmith, Kellen Allison 16 July 2007 (has links)
Societies are becoming increasingly urban and isolated from natural areas. Protecting certain natural areas is vital for building and maintaining resilience in ecological systems for the continued conservation of biodiversity and provision of ecological services. The International Union for the Conservation of Nature and Natural Resources (IUCN) promotes the development of systems of protected areas within nations and regions as a sustainable means of preserving the biodiversity within natural areas. Allowing sustainable ecotourism and wildlife-based recreation activities in protected areas can provide economic incentives to surrounding communities making protection an attractive alternative to more extractive forms of land use. Managing the types of allowable activities and monitoring visitation rates provide managers with vital information regarding the impacts of human interaction with natural systems in protected areas. Texas supports a system of wildlife management areas (WMAs) throughout the state in an attempt to represent each ecoregion and provide essential conservation and recreation needs to the residents of Texas. By analyzing possible influential factors on visitation rates such as size of each area and allowable activities within each WMA, and other influential factors of these protected areas, it should be possible to determine if this type of management scheme is effectively meeting the goals and objectives of protected areas in the state of Texas while effectively providing for the demands of the Texas public. Through resource management initiatives and cooperation with national agencies, WMAs serve as an effective management tool for natural resource protection and conservation for the state of Texas.
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Biogeomorphic Evaluation of Caminada-Moreau Maritime Beach Ridges with Respect to Future Restoration InitiativesDidier, Hannon 12 July 2007 (has links)
Restoration efforts within the coastal zone of southern Louisiana have assumed greater importance in the wake of recent storms and ever increasing sea level rise. A poorly studied geomorphic structure known as the Caminada-Moreau maritime beach ridge complex exists along the southeastern Louisiana coastline between Grand Isle and the Port of Fourchon. Active subsidence in the area has reduced the overall elevation of these structures, decreasing the live cover of its most noticeable feature, stands of Quercus virginiana (live oak), along the ridge spines.
Elevation data was gathered along and across four randomly selected ridges in the study area with survey-grade differential GPS techniques. Calculated precision for these measurements, with respect to the base station, was ± 1.9 mm horizontally and ± 4.8 mm vertically (North American Vertical Datum 1988). Elevations in the study site ranged from 2.3 cm to 80.5 cm.
Moisture content, bulk density, pH, soil salinity, loss on ignition, total carbon, total nitrogen, and total phosphorus data were plotted against elevation data and modeled statistically. Significant negative correlations existed between elevation and all soil properties measured except pH and bulk density, which had significant positive correlations with elevation.
Plant species identification, cover data, height, and basal diameter were gathered at each surveyed and sampled location in order to determine species richness, dominance, and relative dominance. Species richness was plotted against elevation and statistically modeled, which resulted in a highly significant (p<0.0001), positive correlation (r=0.72). Dominance was used to produce a relevant species list from the original list of 25 identified species. As herbaceous species dominance decreased with increasing elevation, shrub dominance increased. Trees were only found in the highest elevation category.
These data can provide a guideline for future restoration initiatives in the study area. A restored ridge spine elevation of 1.6 m (NAVD 88) is recommended, taking into account local subsidence rates and sea level rise, mean elevation data for Quercus virginiana, and a project life of 100 years. A volume estimate of 1.6 million m<sup>3</sup> of sediment may be necessary to restore all 27 km in the study site to the recommended elevation.
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Use of an Agricultural Non-Point Source Pollution Model to Assess Impacts of Development and Management Practices in an Urban WatershedCross, John Admiral 13 July 2007 (has links)
A Geographical Information System (GIS) linked to a Non-Point Source (NPS) model are being used to predict the effectiveness of storm water management strategies and examine the impact of proposed land use changes on Total Maximum Daily Load (TMDL) attainment. This study tests a methodology for analyzing land use changes and management using GIS analyses of impervious surfaces and AGricultural Non-Point Source (AGNPS) pollution modeling in an approximate 1100 acre urban watershed located in East Baton Rouge Parish (EBRP), Louisiana. The GIS analyses of Total Impervious Area (TIA) quantified increases in urbanization and provided land use data utilized in AGNPS modeling in a small urban watershed which also included a natural swamp park. AGNPS modeling was executed in several different scenarios to predict changes in NPS loadings associated with increases in TIA, its subsequent management and Digital Elevation Model (DEM) grid cell size. Data was processed and edited using ArcView (3.2) and GeoMedia (6) GIS systems. The test watershed underwent significant urbanization in the 8 years between 1996 and 2004, causing an increase in quantity and decrease in quality of subsequent runoff, and these created measurable impacts in the swamp park. Predictions of sediment, erosion and runoff were compared for each scenario year. Management practices were also simulated. TIA increased by 8.47 % from 1996 to 2004 and pavement counted for the greatest increase. Differences in Average Annual Outputs (AAOs) for 5m and 25m DEMs varied greatly with 5m simulations providing less in sediment erosion, load, yield, and runoff. The differences in simulations based on TIA assignment in 5m also varied from those based on TIA. Changes in AAOs based on the increase in TIA and the implementation of permeable pavements resulted in a maximum reduction of 43%, 8%, 3% and a 1% reduction in erosion yield, runoff, load and erosion respectively. Urbanization of the BSW is still continuing today and now has even greater imperviousness. The proposed methodology might be adopted by planners and managers to forecast water quality and storm water management implications of proposed projects on downstream TMDL attainment.
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Denitrification Capacity and Denitrifying Bacteria in a Restored Bottomland Hardwood Forest, Mississippi River Alluvial Valley: Hydrological ImpactsLi, Yan 17 July 2007 (has links)
Mississippi River Alluvial Valley (MAV) is one of the most important ecosystems in the United States, and bottomland hardwood forests (BLHs) are a major components of this ecosystem. The ecological and hydrological functions of BLHs can help maintain the diversity of species, groundwater balance, and nutrient removal etc. However, due to the increased human activities in the area, most of the BLHs were converted to agricultural land. Realizing the seriousness of the situation of the ecosystem, a series of programs have been carried out by the U.S. Fish and Wildlife Service (USFWS) and the U.S. Department of Agriculture (USDA) to restore the forested wetlands since several decades ago. However, the efficacy of these activities on denitrification is unclear. In this study, field and laboratory studies were carried out to determine the effects of hydrologic restoration (i.e. periodical flooding) on the denitrification capacity and denitrifying bacteria in a 30-year old restored BLH in the Red River Wildlife Management Area (RAWMA) of the MAV, and designed a better cultivation medium for denitrifying bacteria isolation from soils in this area. In-situ denitrification was estimated using the C2H2 block technique with a static chamber and potential denitrification rate was determined in the laboratory using a modification of the denitrification enzyme assay (DEA) method. Both in-situ and potential denitrification rates with amendment of nitrate (NO3-) were significantly (P < 0.05) higher at flooded, lower elevation sites than those of higher elevation sites where the hydrology was not restored. Without amendment of NO3-, no significant differences in potential and in situ denitrification rates were observed between low and high elevations. The population of denitrifying bacteria was measured by the most probable number (MPN) method, and denitrification gene nirK quantified by real-time quantitative PCR. The MPN and PCR results were consistent with each other, without significant differences between the high and low elevation sites. The isolation rates of denitrifying bacteria from the designed medium No. 1 and No. 2 were higher than the classic cultivation medium. The numbers of species isolated by these two media still need to be determined, and compared to the classic one. Further improvement of the medium will be based on the evaluation of this first generation of media.
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Protocol Development for Pro-Active Emergency Responses by Veterinary Clinics and HospitalsBasirico, Laura Marie 14 November 2007 (has links)
The Gulf Coast hurricanes of 2005 necessitated the development of a guidance document concerning emergency preparedness and response for veterinary clinics and hospitals. The aftermaths of the largest natural disasters in United States' history, namely Hurricanes Katrina and Rita, brought to light the need for a protocol designed specifically for veterinarians and veterinary practitioners. Disaster management information was synthesized and modified to be subject-specific for the veterinary community. This synthesis resulted in the creation of the Veterinary Emergency Preparedness and Response (VEPR) manual and website.
Two types of data were collected to develop the emergency protocol; interviews with veterinarians and staff and site visits to affected clinics and hospitals were conducted to gather primary data for inclusion in the preparedness and response document, and preexisting information concerning disaster management from an array of sources was compiled and reviewed. A preliminary manual was provided to affected individuals for feedback and input and the subsequent comments were formatted and incorporated into a final protocol recommendation.
Two deliverables resulted from the current study including a hardcopy VEPR manual and website based on the information from the manual, <a href="http://info.envs.lsu.edu/vepr/"> http://info.envs.lsu.edu/vepr/</a>. The guidance document provides pertinent information for pre-hurricane planning, weathering the physical storm, and post-hurricane recovery. Together the manual and website facilitate the widespread distribution of the emergency recommendations to the veterinary community and are expected to be a comprehensive source for specific disaster management materials. The VEPR manual and website are resources that can be used as tools to mitigate damaging affects, particularly to lessen the post-disaster burden on the staff and operations of veterinary clinics and hospitals.
VEPR provides a foundation for the development of viable emergency preparedness and response protocols for other types of natural disasters. Updates of VEPR will be needed so as to assure that the recommended protocol continues to be timely for national and global applications.
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