Southeastern Louisiana Research Articles

The Evolution of the 2021 Seacor Power Tragedy in Coastal Louisiana

Abstract On 13 April 2021, a mesoscale convective system (MCS) swept across the southeastern Louisiana coast, capsizing the 39-m Seacor Power roughly 7 km from shore and leaving 13 mariners drowned or missing. In addition to the severe straight-line winds that sank the vessel, sustained surface winds > 20 m s−1 behind the leading convection persisted well after the main convective band, inhibiting search and rescue efforts. Though complete historical fatality statistics are unavailable, the 13 deaths associated with this event likely represent one of the deadliest severe convective weather events in modern U.S. maritime history. This analysis integrates in situ, remotely sensed, and reanalysis datasets to reconstruct the 2021 Seacor Power accident as well as ascertain its depiction in day-of operational convection-allowing model (CAM) guidance. Results suggest that the MCS formed along an unanalyzed coastal boundary and developed a strong mesohigh to the east of the wreck as it moved offshore. The resulting zonally oriented pressure gradient directed stiff easterly winds over the wreck for several hours, even as the squall line had propagated well away from the coast. This multihour period of severe weather along the Louisiana coast was relatively well resolved by morning-of CAM guidance, providing optimism that future such events may be anticipated with the lead times required by vulnerable seacraft to reach safe harbor. Future severe convective weather watches containing marine zones might include a “marine” section detailing the potential sea conditions, analogous to the “aviation” section in current severe weather watches.

Effectiveness of regional risk mitigation policies in equitably improving connectivity to essential service during hurricane-induced floods

This study aimed to evaluate the effectiveness of regional disaster mitigation policies in providing equitable access to essential services during hurricane-induced floods in Southeast Louisiana. Studies have been conducted on access to essential service facilities during and after disasters. However, there is limited research on whether current regional disaster mitigation plans ensure equitable access to emergency facilities. To this end, a methodology was developed to assess the effect of the 2017 Louisiana Coastal Master Plan developed by the Coastal Protection and Restoration Agency (CPRA) on equity in connectivity to essential service facilities (hospitals and fire stations) in a case study region in southeastern Louisiana. First, a graph-based model was used to represent the road network and determine the connectivity of five demographic groups during hurricane-induced flood scenarios. Herein, a hurricane-induced flood scenario with a low return period (50 years) was chosen for future years up to 2065, considering sea level rise and subsidence. Roads with flood depths exceeding 30 cm were considered impassable and were removed from the network. Connectivity was then determined using breadth-first search. Monte Carlo simulations were performed to propagate uncertainties in flood depths. It was found that minority groups were at a higher risk of losing access to emergency services during the selected hazard scenario. Native American and Asian populations were found to be at the highest risk of disconnection, followed by the Hispanic and African-American populations. Overall, the coastal master plan did not affect the equity (or lack thereof) in connectivity to essential service facilities.

Association between long-term exposure to fine particulate matter and mental health in women from Southeastern Louisiana, USA

Association between long-term exposure to fine particulate matter and mental health in women from Southeastern Louisiana, USA

Short-term Associations of Ambient Fine Particulate Matter on Mental Distress and Depression in Women of Southeastern Louisiana

Short-term Associations of Ambient Fine Particulate Matter on Mental Distress and Depression in Women of Southeastern Louisiana

Toxic Ethylene Oxide May Exceed Safe Levels In Cancer Alley

Concentrations of the cancer-causing chemical far surpass EPA threshold levels for safety in southeastern Louisiana.

Ethylene Oxide in Southeastern Louisiana's Petrochemical Corridor: High Spatial Resolution Mobile Monitoring during HAP-MAP.

Ethylene oxide ("EtO") is an industrially made volatile organic compound and a known human carcinogen. There are few reliable reports of ambient EtO concentrations around production and end-use facilities, however, despite major exposure concerns. We present in situ, fast (1 Hz), sensitive EtO measurements made during February 2023 across the southeastern Louisiana industrial corridor. We aggregated mobile data at 500 m spatial resolution and reported average mixing ratios for 75 km of the corridor. Mean and median aggregated values were 31.4 and 23.3 ppt, respectively, and a majority (75%) of 500 m grid cells were above 10.9 ppt, the lifetime exposure concentration corresponding to 100-in-one million excess cancer risk (1 × 10-4). A small subset (3.3%) were above 109 ppt (1000-in-one million cancer risk, 1 × 10-3); these tended to be near EtO-emitting facilities, though we observed plumes over 10 km from the nearest facilities. Many plumes were highly correlated with other measured gases, indicating potential emission sources, and a subset was measured simultaneously with a second commercial analyzer, showing good agreement. We estimated EtO for 13 census tracts, all of which were higher than EPA estimates (median difference of 21.3 ppt). Our findings provide important information about EtO concentrations and potential exposure risks in a key industrial region and advance the application of EtO analytical methods for ambient sampling and mobile monitoring for air toxics.

Dust Storms as Global Disseminators of Plant Pathogens

This contemporary mycological inquiry investigates into the escalating threat to global food security posed by the dispersal of plant pathogens through airborne dust, exemplified by the simulation of a colossal dust storm, named “Godzilla”. Employing advanced computational models, researchers trace the route of Fusarium oxysporum spores from North Africa across the Atlantic, settling in the Caribbean and southeastern United States. The study estimates the conveyance of over 13,000 viable spores, raising concerns about their impact on agricultural regions, particularly southeastern Louisiana, Mexico, Haiti, the Dominican Republic, and Cuba. While ultraviolet radiation typically neutralizes airborne spores within three days, the focus shifts to spore viability upon landing in vulnerable agricultural zones. Proximity to the dust source in intercontinental regions intensifies the risk, emphasizing the need to understand fungal disease dynamics and identify susceptible agricultural areas. Global prevalence of F. oxysporum and its capacity to infect over 100 crops highlight the potential for significant crop losses and economic consequences. The research underscores the urgency of comprehending disease dissemination dynamics and protecting global food security, emphasizing regions like sub-Saharan Africa as critical sources of viable spores. The study’s preliminary nature prompts a future focus on observational data acquisition, including comprehensive dust storm mapping and genetic comparisons of F. oxysporum, to validate the model’s findings. This research work calls for proactive measures to address the escalating threat of disease, laying the ground work for forthcoming mycological endeavors

MAXIMUM LIKELIHOOD ALGORITHM DETECTS COASTAL WETLAND CHANGES IN TWO CONTRASTING COASTAL WETLANDS IN LOUISIANA

Abstract. Louisiana coastal wetlands contain about 37 percent of the estuarine herbaceous marshes in the conterminous United States. However, the combined effect of sea level rise and other anthropogenic factors have altered land use land cover over the last few years. This is true for two wetlands in coastal Louisiana, Barataria bay and Wax Lake delta. Barataria Bay, Louisiana, USA has experienced significant land loss. Updated information on the dynamics of change in these wetlands is limited and poorly documented. This information is necessary to develop strategies that will contribute to reversing and halting degradation. Thus, this study employed the Maximum Likelihood classifier on Landsat satellite imagery to assess land use and land cover changes in Barataria Bay and Wax Lake Delta, southeastern Louisiana, USA. The analysis revealed notable alterations in the land cover patterns over the study period. In Barataria Bay, there was a decrease in salt marsh areas with a corresponding increase in open water and Built-up area. In contrast, Wax Lake Delta demonstrated substantial land/wetland growth, with significant expansion of vegetation cover. The Maximum Likelihood classifier demonstrated high accuracy in classifying the land cover types, with an overall accuracy of 86% for Barataria Bay and 92% for Wax Lake Delta. These results highlight the effectiveness of the classifier in accurately identifying and mapping land cover changes in coastal environments. The findings contribute valuable insights for understanding the dynamics of coastal ecosystems and can inform decision-making processes for coastal management and conservation efforts.

Examining the effects of cumulative environmental stressors on Gulf Coast child and adolescent health.

This study examines how community-level cumulative environmental stress affects child and adolescent emotional distress and chronic health conditions both directly and indirectly through stressors at the household, family, and individual levels. Data comes from the Women and their Children's Health (WaTCH) Study, which sought to understand the health implications of exposure to the 2010 Deepwater Horizon oil spill (DHOS) among a cohort of 596 mothers with children ages 10 to 17 in southeastern Louisiana. Community-level environmental stress was measured using a newly developed geospatial index. Household-level stressors included previous hurricane impacts, impacts of DHOS, degree of financial difficulty, and degree of housing physical decay. Family stressors included maternal depression, self-rated physical health, and degree of parenting stress. Child stress was based on perceived stress; child mental health was based on serious emotional disturbance; and child physical health was based on diagnosis of chronic illness. Structural equation modeling used weighted least squares means and variance and theta parameterization. Results showed a significant negative direct path between community-level cumulative environmental stress and child/adolescent serious emotional disturbance and chronic illness. However, the indirect relationship through household, family, and individual-level stressors was significant and positive for both child/adolescent serious emotional disturbance and chronic illness. These findings point to the centrality of the household and family in determining child and adolescent physical and mental health outcomes in communities exposed to frequent disasters and ongoing environmental stressors.

COVID-19 vaccination likelihood among federally qualified health center patients: Lessons learned for future health crises

BackgroundTo prepare for rollout of a COVID-19 vaccine in fall 2020, there was an urgent need to understand barriers to ensuring equitable access and addressing vaccine skepticism and resistance. This study aimed to understand the association between trusted sources of COVID-19 information and likelihood of vaccination during that time, focusing on lessons learned to prepare for future public health crises. MethodsFrom December 2020-March 2021, we surveyed a probability-based, cross-sectional sample of 955 patients across seven federally qualified health centers (FQHCs) serving predominantly low-income, Black and White populations in southeastern Louisiana. Vaccination likelihood was measured on a 7-point scale; “very likely to vaccinate” was defined as score=7. Trust in healthcare provider was measured with a single survey item. High trust in personal contacts, government, and media, respectively, were defined as the highest tertiles of summative scores of trust items. Weighted multivariable logistic regression estimated adjusted odds ratios (aOR) and 95% confidence intervals (CI) for being very likely to vaccinate. ResultsParticipants were 56% Black, 64% women, mean age 44.6 years; 33% were very likely to vaccinate. High trust in healthcare provider (aOR=4.14, 95% CI 2.26–7.57) and government sources (aOR=3.23, 95% CI 1.98–5.28) were associated with being very likely to vaccinate. ConclusionsDuring initial COVID-19 vaccination rollout, trust in healthcare providers and government sources of COVID-19 information was associated with likelihood to vaccinate in FQHC patients. To inform public health planning for future crises, we highlight lessons learned for translating community-relevant insights into direct action to reach those most impacted.

FloodSafeHome: evaluating financial benefits and savings of freeboard for improved decision-making in flood risk mitigation

Freeboard—elevation of a structure above the base flood elevation (BFE)—is a critical component in mitigating or avoiding flood losses. However, the unrevealed benefits and savings of freeboard installation have prevented communities from adopting this approach. To improve decision-making for residents, prospective residents, and other stakeholders in flood-vulnerable communities and enhance flood risk mitigation strategies, this study presents the methodology underlying a new webtool, FloodSafeHome, that estimates comprehensively the economic benefits and savings of freeboard installation for new construction of residential buildings. Specifically, the proposed evaluation framework has been designed to calculate monthly savings for individual buildings by assessing freeboard cost, insurance savings per year, and expected annual flood loss. This new evaluation method is built into a web-based, decision-making tool for use by the public and community leaders in three southeastern Louisiana parishes (i.e., counties), to identify expected future benefits of building residences with freeboard and enhance their decision-making processes with interactive risk/benefit analysis features. For example, results indicate the levels of freeboard that optimize the cost-benefit ratio for flood-insured homes in the study area. This approach is expected to improve long-term flood resilience and provide cost-efficient flood mitigation strategies, particularly in disaster vulnerable regions.

Spatial and temporal variation in exploitation rates of the Louisiana blue crab spawning stock

AbstractObjectiveBlue crabs Callinectes sapidus support one of our nation's most valuable fisheries, and Louisiana has led national landings from 2012 to 2021. Fishery‐independent estimates of abundance have declined in recent years; in 2015, the Louisiana spawning stock biomass reached the lowest point ever recorded. Management efforts for the blue crab spawning stock have been hindered by incomplete knowledge of the dynamics of natural and fishing mortality. The purpose of this study was to examine spatiotemporal variation in exploitation rates of the Louisiana blue crab spawning stock.MethodsFrom 2016 to 2017, we conducted a mark–recapture study in three Louisiana estuaries. During this period, we tagged 6133 mature female blue crabs, of which 964 were recaptured. Exploitation rate estimates were calculated using recapture data. In 2018, Louisiana implemented a 2‐month female harvest prohibition; to examine impacts of this harvest prohibition on exploitation rates of female blue crabs, we tagged additional females before, during, and after the harvest prohibition.ResultOverall exploitation rate estimates for 2016–2017 ranged from 0.27 to 0.30 (i.e., 27–30%), but significant spatial and temporal variation was observed. During 2018, estimated exploitation rate without the harvest prohibition was 0.16–0.18, but with the prohibition, exploitation rate decreased to 0.08–0.09, indicating that this management action was effective in reducing mortality of mature females.ConclusionNearly one‐third of mature female blue crabs in southeastern Louisiana are captured in the fishery at some point during their life. The 2018 female harvest prohibition reduced exploitation rate of mature females by ~50%. These spatiotemporal estimates of exploitation rate will be directly applicable to future Louisiana blue crab management plans and stock assessments.

Unstructured-grid approach to develop high-fidelity groundwater model to understand groundwater flow and storage responses to excessive groundwater withdrawals in the Southern Hills aquifer system in southeastern Louisiana (USA)

Study regionThe Southern Hills aquifer system (SHAS) in the Louisiana Capital Area Groundwater Conservation District (CAGCD), USA. Study focusThe SHAS provides abundant groundwater for public and industrial supplies in the CAGCD. Groundwater depletion, saltwater intrusion, and land subsidence are potential concerns due to prolonged excessive groundwater withdrawals. This study develops a high-fidelity groundwater flow model utilizing a complex unstructured grid to investigate groundwater flow and storage responses to excessive groundwater withdrawals for the SHAS in the CAGCD. The groundwater model incorporates the Mississippi River alluvial aquifer down to the Miocene sands extending to depths around 1 km. New hydrological insightsGroundwater modeling results indicate large cones of depression in the Evangeline and Jasper formations in the Baton Rouge area due to prolonged groundwater withdrawals. Low-permeability faults are inferred by significant groundwater level difference across the faults. While local groundwater storage depletion in deeper aquifers is evident, overall estimated groundwater storage changes of the SHAS in the CAGCD are close to zero in the past two decades, indicating insignificant groundwater storage changes. This is attributed to dominant interactions between the major rivers and the shallower alluvial aquifer. In addition, the simulated groundwater storage changes exhibit patterns similar to those derived by the Gravity Recovery and Climate Experiment (GRACE) model that has been used in evaluation of groundwater depletion in many regional studies.

Modeling current and future habitat suitability of an iconic bird to inform restoration planning in southeastern Louisiana, U.S.A.

Louisiana is facing a land loss crisis with 5,000 km2 lost since the 1930s, and another 10,000 km2 may disappear over the next 50 years. In response, the state developed a Comprehensive Master Plan for a Sustainable Coast, which includes predictions for how wildlife species respond to futures with or without restoration action. However, the 2017 Master Plan did not include a bird species representative of brackish or freshwater wetland habitats. Our objective therefore was to evaluate the potential for the Bald Eagle (Haliaeetus leucocephalus) to serve as an indicator of freshwater wetland health, and to develop a model to predict Bald Eagle responses to land cover change 20 and 50 years into the future, with or without restoration action. Using nest location data collected by the Louisiana Department of Wildlife and Fisheries from the Barataria Basin, we modeled the relationship between Bald Eagle nest occurrence and land cover using boosted regression trees. Model performance was strong, explaining 54.4 ± 0.1% of the deviance in nest occurrence, and showed that Bald Eagle nests were more common in areas with greater fresh forested wetland, freshwater marsh, and flotant marsh land cover. Future suitability for nesting Bald Eagles was higher in 20 and 50 years with restoration action compared to without, although suitability in both years was lower than contemporary suitability, regardless of restoration action. Our model suggests that comprehensive restoration action is needed, including the implementation of Mississippi River diversions, to sustain high densities of nesting Bald Eagles in coastal Louisiana.

Reading The Awakening after Hurricane Katrina

“Every hour and a half, Louisiana sheds another football field’s worth of land.” “The problem of the Anthropocene is a problem of perception, but it is also a problem of the politics of denial, the administration of forgetting.” “It is not a healthy book.” Long before Hurricane Katrina pummeled New Orleans in 2005, another hurricane decimated the region. In 1893, the Hurricane of Cheniere Caminada, also known as the Great October Storm, swept away virtually all the structures on the barrier islands and flooded the city. Throughout coastal Southeastern Louisiana, more than two thousand people perished in the storm, mostly from the storm surge; homes and ships were demolished. One contemporary newspaper article described the scene in stark terms: “Everywhere one could see graves, wherein as many as ten people were buried. Some were drowned; others killed in the wreckage. There are hundreds of bodies that are still unburied” (Savannah). Such descriptions were commonplace in national publications, which circulated eyewitness accounts of the devastation, and numerous writers published narratives of the storm. The Great October Storm was the worst natural disaster in US history up until that point and remains one of the costliest, most lethal hurricanes on record.

Water quality and antibiotic resistance in the recreational waters

The overuse and improper disposal of antibiotics results in antibiotic resistance. This raises concern over the presence of antibiotic resistant bacteria (ARB) in waterways and pose health risks of antibiotic resistant infections to water recreationists. The purpose of this study was to monitor water quality, microbial ecology, and antibiotic resistance in water and biofilm on submerged plastics at two public boat launches in southeastern Louisiana. Water and biofilm samples were collected once a month, in triplicate, from two public boat launches in Louisiana, USA for a year. Water quality metrics included nitrate, ammonia, sulfate, phosphate, and organic carbon. Water samples were tested for total and fecal coliform abundance and the presence of ARB. Out of 131 bacterial isolates studied from these two sites, 86% of them tested positive for antibiotic resistance with multi-drug resistance. Antibiotic resistance genes (ARGs) for sulfonamide (sul2), bacitracin (bacA) and ampicillin (ampA) were identified in bacterial isolates from water and biofilm samples at both sites. Molecular genetic diversity analysis identified distinct taxonomic diversity differences in biofilm bacteria compared to the planktonic bacteria in the surrounding water. Biofilm samples showed increased diversity at the phylum, genus, and species levels.

Assessing the Impact of COVID-19 Phased Vaccine Eligibility on COVID-19 Vaccine Intent among African Americans in Southeastern Louisiana: A Community-Based, Cohort Study.

Four hundred eighty-seven African American participants in southeastern Louisiana were surveyed from January-April of 2021, with follow-up surveys occurring in Fall 2021. Survey domains included demographics, vaccine hesitancy, discrimination in the healthcare setting, and knowledge and experiences with COVID-19. Descriptive statistics, Chi-square tests, and binary logistic regression were performed. Participants eligible for the vaccine were 1.61 times as likely to express positive vaccine intent versus ineligible participants. Additional predictors of vaccine intent were age, insurance status and coverage, and female sex at birth. In the multivariable logistic analysis, eligible individuals were 2.07 times as likely to receive the vaccine versus ineligible individuals. Vaccine eligibility for the COVID-19 vaccine was a significant predictor of intent to vaccinate in the African American community. Younger individuals were less likely to have a positive intent, correlating with the eligibility of ages 16+ occurring 5 months post-vaccine approval.

The Reactionary Romance of American Slave Revolt: Scripting the Unthinkable in the Archive of the 1811 German Coast Uprising

Enslavers and their allies wrote in terrified, apocalyptic terms about slave revolts, particularly in the late eighteenth- and early nineteenth-century US. This essay suggests that by consistently framing slave revolt in these ways, proslavery white Americans constructed and reproduced a dominant, normative narrative about the meaning of Black self-determination, which this essay calls a "reactionary romance." This "romance" deemed Black self-determination an apocalypse-signaling antagonist against which the privileged body politic must continually and violently struggle in order to reproduce itself. It perversely drew on the rebellious actions of Black people as a way to enclose the prospect of Black freedom in a shroud of terror, rendering the suppression of Black self-determination an esteemed civic duty for the American citizen. This essay critically and historically analyzes this romance as it functions in archival documentation of the 1811 German Coast Uprising in southeastern Louisiana, the largest slave revolt in US history. The way that Louisiana planters told the story of the 1811 Uprising weaponized the reactionary romance to compel an expanding American empire (and its citizens) to protect and expand both the social and material structures of plantation slavery and the limits on moral and political imagination that attended these structures.

Mechanisms of recovery: Community perceptions of change and growth following multiple disasters.

The geographic location of the Gulf South leaves communities in continuous threat, response, and recovery disaster cycles. Hurricane Katrina in 2005 provided an opportunity to study disaster mental health. Less than 5 years after the storm, many Hurricane Katrina survivors were impacted again by the Deepwater Horizon Gulf oil spill. Despite adversities impacting Gulf communities, over 90% of participants reported they were resilient. The purpose of this study was to improve the understanding of the mechanisms that contribute to strengths following adversity in communities affected by repeated disasters. Specifically, we focused on survivor perceptions of personal, spiritual, or community changes in efforts to describe community resilience and posttraumatic growth (PTG). Participants were recruited through a quantitative survey and community flyers. Participants represented southeastern Louisiana, in areas impacted by hurricanes and the oil spill-for a total of five focus groups and 41 participants. Focus groups began by asking each participant to provide a brief overview of their disaster survival story and three additional guiding strengths-based questions. Data were transcribed using Dragon Speech Recognition software. A total of 963 unique responses were analyzed and coded. The following themes were identified: connectedness (n = 259), coping (n = 94), spirituality (n = 60), adaptability (n = 47), and self-reliance (n = 23). Participants noted a growth mindset from the disasters and also acknowledged coinciding negative experiences (n = 154) associated with community change and loss, where subthemes included change in connectedness (n = 97), crime (n = 26), and feeling like an outsider (n = 31). These findings help scholars and mental health practitioners better understand the lived experiences of PTG in a community of survivors impacted by recurring traumatic experiences. In keeping with previous literature, PTG and negative experiences associated with trauma are not mutually exclusive, but occur simultaneously. Our results offer a holistic picture of coping with cumulative or repeated traumas and suggest that connectedness, coping, and spirituality provide important buffers to negative psychosocial outcomes.

Origin of sodium bicarbonate groundwaters, Southern Hills Aquifer System, USA by silicate hydrolysis

Groundwaters dominated by sodium-bicarbonate represent an important end-member continental water type. The Southern Hills aquifer system in southwestern Mississippi and southeastern Louisiana, USA provides an excellent field laboratory for studying the origin and evolution of Na–HCO3 groundwaters in siliciclastic aquifers. Our research, which is based on establishing spatial variations in water chemistry, mass balance relations, and thermodynamic considerations, supports the hypothesis that the process of generating Na–HCO3 groundwaters in the Southern Hills aquifer system is driven by irreversible dissolution-precipitation reactions primarily involving silicate minerals, not by calcite dissolution and cation exchange, as has been proposed by others. The evidence supports the following scenario: oxidation of organic carbon produces organic acids which react with detrital plagioclase feldspars having an average bulk composition of approximately Ab0.70An0.30. In the up-gradient part of the system, the incongruent dissolution of plagioclase produces a kaolinite phase and releases dissolved silica, Na, Ca, and HCO3 into solution. As the silica concentration and the sodium/hydrogen ion activity ratio in the waters increase down gradient, the waters become saturated with respect to a (Na,Ca)-smectite. As plagioclase hydrolysis continues as a result of production of carbonic acid, there is a progressive increase in (Na+/H+) and (Ca2+/(H+)2) activity ratios and now a progressive decrease in dissolved H4SiO40 as a result of buffering by kaolinite-smectite. It is likely that some Ca is preferentially removed from solution over Na by adsorption on newly-formed smectite. In the most distal parts of the aquifer system the high bicarbonate alkalinity and high pH result in the waters becoming saturated with respect to calcite, and the precipitation of calcite is another probable sink for Ca. Using dissolved bicarbonate as a reaction progress variable provides a useful technique for evaluating controls on groundwater compositions. It is also clear that the evolution of groundwater compositions in this and similar systems cannot be understood without understanding the controls on dissolved silica.