COS Faculty Works
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Item 3D Genital shape complexity in female marine mammals(Wiley Online Library, 2021-02-15) Orbach, Dara N.; Brassey, Charlotte A.; Gardiner, James D.; Brennan, Patricia L. R.; Orbach, Dara N.; Brassey, Charlotte A.; Gardiner, James D.; Brennan, Patricia L. R.Comparisons of 3D shapes have recently been applied to diverse anatomical structures using landmarking techniques. However discerning evolutionary patterns can be challenging for structures lacking homologous landmarks. We used alpha shape analyses to quantify vaginal shape complexity in 40 marine mammal specimens including cetaceans, pinnipeds, and sirenians. We explored phylogenetic signal and the potential roles of natural and sexual selection on vaginal shape evolution. Complexity scores were consistent with qualitative observations. Cetaceans had a broad range of alpha complexities, while pinnipeds were comparatively simple and sirenians were complex. Intraspecific variation was found. Three-dimensional surface heat maps revealed that shape complexity was driven by invaginations and protrusions of the vaginal wall. Phylogenetic signal was weak and metrics of natural selection (relative neonate size) and sexual selection (relative testes size, sexual size dimorphism, and penis morphology) did not explain vaginal complexity patterns. Additional metrics, such as penile shape complexity, may yield interesting insights into marine mammal genital coevolution. We advocate for the use of alpha shapes to discern patterns of evolution that would otherwise not be possible in 3D anatomical structures lacking homologous landmarks.Item A 10-year Metocean dataset for Laguna Madre, Texas, including for the study of extreme cold events(2023-11-28) White, Miranda C.; Vicens-Miquel, Marina; Tissot, Philippe; Krell, EvanCoastal observations along the Texas coast are valuable for many stakeholders in diverse domains. However, the management of the collected data has been limited, creating gaps in hydrological and atmospheric datasets. Among these, water and air temperature measurements are particularly crucial for water temperature predictions, especially during freeze events. These events can pose a serious threat to endangered sea turtles and economically valuable fish, which can succumb to hypothermic stunning, making them vulnerable to cold-related illness or death. Reliable and complete water and air temperature measurements are needed to provide accurate predictions of when cold-stunning events occur. To address these concerns, the focus of this paper is to describe the method used to create a complete 10-year dataset that is representative of the upper Laguna Madre, TX using multiple stations and various gap-filling methods. The raw datasets consist of a decade’s worth of air and water temperature measurements within the Upper Laguna Madre from 2012 to 2022 extracted from the archives of the Texas Coastal Ocean Observation Network and the National Park Service. Large portions of data from the multiple stations were missing from the raw datasets, therefore a systematic gap-filling approach was designed and applied to create a near-continuous dataset. The proposed imputation method consists of three steps, starting with a short gap interpolation method, followed by a long gap-filling process using nearby stations, and finalized by a second short gap interpolation method. This systematic data imputation approach was evaluated by creating random artificial gaps within the original datasets, filling them using the proposed data imputation method, and assessing the viability of the proposed methods using various performance metrics. The evaluation results help to ensure the reliability of the newly imputed dataset and the effectiveness of the data imputation method. The newly created dataset is a valuable resource that transcends the local cold-stunning issue, offering viable utility for analyzing temporal variability of air and water temperatures, exploring temperature interdependencies, reducing forecasting uncertainties, and refining natural resource and weather advisory decision-making processes. The cleaned dataset with minimal gaps (<2%) is ready and convenient for artificial intelligence and machine learning applications.Item A meta-analysis of disturbance caused by drones on nesting birds(2023) Cantu de Leija, Antonio; Mirzadi, Rostam E.; Randall, Jessica M.; Portmann, Maxwell D.; Mueller, Erin J.; Gawlik, Dale E.The use of drones for monitoring nesting birds is rapidly increasing given their affordability and efficiency in bird detection and quantification across habitats. Reports of disturbance caused by drones on different bird species have been mixed, with no consensus on the degree to which different factors affect disturbance responses. Given the lack of systematic assessments of disturbance from drones on nesting birds, we conducted a formal meta-analysis to quantify the degree of disturbance caused by multi-rotor drones on nesting birds, with a particular focus on the effects of altitude of flights and species nesting traits. Seventeen studies met our criteria for inclusion in the analysis, from which we extracted 31 effect sizes in the form of log-odds ratio. Drones showed a small disturbance effect (-1.54; 95% CI: -2.83, -0.26) on nesting birds overall, but heterogeneity was large. Drone flights > 50 m showed no evidence of disturbance on nesting birds. Conversely, flights at lower altitudes (≤ 50 m) showed stronger evidence of disturbance effects, with the largest odds of disturbance observed on ground solitary and non-ground solitary nesters. Only ground colonial nesters showed no evidence of disturbance regardless of the drone altitude. We conclude that the use of drones can be an efficient and safe means of surveying nesting birds if altitude and nesting traits are considered in survey protocols. RESUMEN. El uso de drones para monitorear las aves que anidan está aumentando rápidamente dada su asequibilidad y eficiencia en la detección y cuantificación de aves en todos los hábitats. Los informes de perturbaciones causadas por drones en diferentes especies de aves han sido mixtos, sin consenso sobre el grado en que los diferentes factores afectan las respuestas de perturbación. Dada la falta de evaluaciones sistemáticas de la perturbación de los drones en las aves que anidan, realizamos un metanálisis formal para cuantificar el grado de perturbación causada por drones multirotor en las aves que anidan, haciendo foco en particular en los efectos de la altitud de los vuelos y los rasgos de anidación de las especies. Diecisiete estudios cumplieron los criterios de inclusión en el análisis, de los cuales se extrajeron 31 tamaños del efecto en forma de relación logarítmica de probabilidades. Los drones mostraron un pequeño efecto de perturbación (-1,54; IC del 95%: -2,83, -0,26) en las aves que anidan en general, pero la heterogeneidad fue grande. Los vuelos de drones > 50 m no mostraron evidencia de perturbación en las aves que anidan. Por el contrario, los vuelos a altitudes más bajas (≤ 50m) mostraron una mayor evidencia de efectos de perturbación, con las mayores probabilidades de perturbación observadas en anidadores solitarios y no terrestres. Solo los anidadores coloniales terrestres no mostraron evidencia de perturbación, independientemente de la altitud del dron. Concluimos que el uso de drones puede ser un medio eficiente y seguro para inspeccionar las aves que anidan si la altitud y los rasgos de anidación se consideran en los protocolos de monitoreo.Item Abundance, size, and survival of recruits of the reef coral Pocillopora acuta under ocean warming and acidification(2020-02-04) Bahr, Keisha D.; Tran, Tiana; Jury, Christopher P.; Toonen, Robert J.Ocean warming and acidification are among the greatest threats to coral reefs. Massive coral bleaching events are becoming increasingly common and are predicted to be more severe and frequent in the near future, putting corals reefs in danger of ecological collapse. This study quantified the abundance, size, and survival of the coral Pocillopora acuta under future projections of ocean warming and acidification. Flow-through mesocosms were exposed to current and future projections of ocean warming and acidification in a factorial design for 22 months. Neither ocean warming or acidification, nor their combination, influenced the size or abundance of P. acuta recruits, but heating impacted subsequent health and survival of the recruits. During annual maximum temperatures, coral recruits in heated tanks experienced higher levels of bleaching and subsequent mortality. Results of this study indicate that P. acuta is able to recruit under projected levels of ocean warming and acidification but are susceptible to bleaching and mortality during the warmest months.Item Abundance, size, and survival of recruits of the reef coral Pocillopora acuta under ocean warming and acidification(PLOS ONE, 2020-02-04) Tran, Tiana; Jury, Christopher P.; Bahr, Keisha D.; Toonen, Robert J.Ocean warming and acidification are among the greatest threats to coral reefs. Massive coral bleaching events are becoming increasingly common and are predicted to be more severe and frequent in the near future, putting corals reefs in danger of ecological collapse. This study quantified the abundance, size, and survival of the coral Pocillopora acuta under future projections of ocean warming and acidification. Flow-through mesocosms were exposed to current and future projections of ocean warming and acidification in a factorial design for 22 months. Neither ocean warming or acidification, nor their combination, influenced the size or abundance of P. acuta recruits, but heating impacted subsequent health and survival of the recruits. During annual maximum temperatures, coral recruits in heated tanks experienced higher levels of bleaching and subsequent mortality. Results of this study indicate that P. acuta is able to recruit under projected levels of ocean warming and acidification but are susceptible to bleaching and mortality during the warmest months.Item Acclimatization drives differences in reef-building coral calcification rates(MDPI, 2020-09-08) Barnhill, Kelsey Archer; Jogee, Nadia; Brown, Colleen; McGowan, Ashley; Rodgers, Ku’ulei; Bryceson, Ian; Bahr, Keisha D.; Barnhill, Kelsey Archer; Jogee, Nadia; Brown, Colleen; McGowan, Ashley; Rodgers, Ku’ulei; Bryceson, Ian; Bahr, Keisha D.Coral reefs are susceptible to climate change, anthropogenic influence, and environmental stressors. However, corals in Kāneʻohe Bay, Hawaiʻi have repeatedly shown resilience and acclimatization to anthropogenically-induced rising temperatures and increased frequencies of bleaching events. Variations in coral and algae cover at two sites—just 600 m apart—at Malaukaʻa fringing reef suggest genetic or environmental differences in coral resilience between sites. A reciprocal transplant experiment was conducted to determine if calcification (linear extension and dry skeletal weight) for dominant reef-building species, Montipora capitata and Porites compressa, varied between the two sites and whether or not parent colony or environmental factors were responsible for the differences. Despite the two sites representing distinct environmental conditions with significant differences between temperature, salinity, and aragonite saturation, M. capitata growth rates remained the same between sites and treatments. However, dry skeletal weight increases in P. compressa were significantly different between sites, but not across treatments, with linear mixed effects model results suggesting heterogeneity driven by environmental differences between sites and the parent colonies. These results provide evidence of resilience and acclimatization for M. capitata and P. compressa. Variability of resilience may be driven by local adaptations at a small, reef-level scale for P. compressa in Kāneʻohe Bay.Item Acclimatory plasticity drives differences in reef-building coral calcification rates(MDPI, 2020-09-08) Barnhill, Kelsey Archer; Jogee, Nadia; Brown, Colleen; McGowan, Ashley; Rodgers, Ku’ulei; Bryceson, Ian; Bahr, Keisha D.; Barnhill, Kelsey Archer; Jogee, Nadia; Brown, Colleen; McGowan, Ashley; Rodgers, Ku’ulei; Bryceson, Ian; Bahr, Keisha D.Coral reefs are susceptible to climate change, anthropogenic influence, and environmental stressors. However, corals in Kāneʻohe Bay, Hawaiʻi have repeatedly shown resilience and acclimatization to anthropogenically-induced rising temperatures and increased frequencies of bleaching events. Variations in coral and algae cover at two sites—just 600 m apart—at Malaukaʻa fringing reef suggest genetic or environmental differences in coral resilience between sites. A reciprocal transplant experiment was conducted to determine if calcification (linear extension and dry skeletal weight) for dominant reef-building species, Montipora capitata and Porites compressa, varied between the two sites and whether or not parent colony or environmental factors were responsible for the differences. Despite the two sites representing distinct environmental conditions with significant differences between temperature, salinity, and aragonite saturation, M. capitata growth rates remained the same between sites and treatments. However, dry skeletal weight increases in P. compressa were significantly different between sites, but not across treatments, with linear mixed effects model results suggesting heterogeneity driven by environmental differences between sites and the parent colonies. These results provide evidence of resilience and acclimatization for M. capitata and P. compressa. Variability of resilience may be driven by local adaptations at a small, reef-level scale for P. compressa in Kāneʻohe Bay.Item Activity as a proxy to estimate metabolic rate and to partition the metabolic cost of diving vs. breathing in pre- and post-fasted Steller sea lions(Inter-Research Science Publisher, 2013-04-30) Fahlman, Andreas; Svärd, C.; Rosen, D. A. S.; Wilson, R. P.; Trites, AndrewThree Steller sea lions Eumetopias jubatus, trained to dive voluntarily to depths ranging from 10 to 50 m, were used to determine whether the relationship between activity and metabolic rate during a diving interval (MRDI, dive + surface interval) was affected by fasting (9 d) during the breeding season (spring through summer). We subsequently used the relationship between activity and MRDI to partition the metabolic costs between underwater breath-holding activity and surface breathing activities. We estimated activity from overall dynamic body acceleration (ODBA) measured using a 3-axis accelerometer, and measured MRDI using flow-through respirometry. The relationship between ODBA-based activity and MRDI was not affected by fasting period, suggesting that ODBA can be used to predict energy expenditure regardless of nutritional state in the spring and summer. However, the relationship between ODBA and dive metabolic rate differs from the relationship between ODBA and the surface metabolic rate before diving. Partitioning MRDI into the metabolic cost of remaining at the surface versus swimming underwater suggests that the metabolic cost of diving for Steller sea lions is approximately 29% lower than when breathing at the surface. ODBA appears to be a reasonable proxy to estimate metabolic rate in marine mammals, but more detailed behavioral data may be required to accurately apply the method in the field.Item Air-water exchange and distribution pattern of organochlorine pesticides in the atmosphere and surface water of the open Pacific ocean(Elsevier, 2020-07-02) Li, Yali; Lohmann, Rainer; Zou, Xinqing; Wang, Chenglong; Zhang, LinSurface seawater and lower atmosphere gas samples were collected simultaneously between 18°N and 40°S in the open Pacific Ocean in 2006–2007. Samples were analyzed for organochlorine pesticides (OCPs) to assess their distribution patterns, the role of ocean in the long-range transport (LRT), and the air-water exchange directions in the open Pacific Ocean. Such open ocean studies can yield useful information such as establishing temporal and spatial trends and assessing primary vs secondary emissions of legacy OCPs. Target compounds included hexachlorocyclohexanes (HCHs), dichlorodiphenyltrichloroethanes (DDTs) and its derivatives, and chlordane compounds. Concentrations for α-HCH, γ-HCH, trans-chlordane (TC), and cis-chlordane (CC) were higher in the Northern Hemisphere (NH) than the Southern Hemisphere (SH) in both gaseous and dissolved phases, while the distribution patterns of DDTs and heptachlor exo-epoxide (HEPX) showed a reversed pattern. In the N Pacific, concentrations of α-HCH and γ-HCH in the present work were lower by 63 and 16 times than those observed in 1989–1990. The distribution patterns of DDT suggested there was usage in the SH around 2006. Calculated fugacity ratios suggested that γ-HCH was volatilizing from surface water to the atmosphere, and the air-water exchange fluxes were 0.3–11.1 ng m−2 day−1. This is the first field study that reported the open Pacific Ocean has become the secondary source for γ-HCH and implied that ocean could affect LRT of OCPs by supplying these compounds via air-sea exchange.Item Amage imajimai sp. nov., a new species of Ampharetidae (Annelida: Polychaeta) from Japanese waters(European Journal Of Taxonomy, 2015-11-19) Reuscher, MichaelA new polychaete species of the family Ampharetidae, Amage imajimai sp. nov., is described from deep waters of Sagami Bay, Japan. It is characterized by the possession of four pairs of branchiae, twelve thoracic uncinigers, eleven abdominal uncinigers, and the lack of thoracic notopodial cirri. The new species is named in honor of the renowned Japanese polychaetologist Minoru Imajima. An identification key for all Amage species from Japanese waters is provided.Item Analysing micro- and nanoplastics with cutting-edge infrared spectroscopy techniques: A critical review(2024-03-27) Xie, Junhao; Gowen, Aoife; Xu, Wei; Xu, JunliThe escalating prominence of micro- and nanoplastics (MNPs) as emerging anthropogenic pollutants has sparked widespread scientific and public interest. These minuscule particles pervade the global environment, permeating drinking water and food sources, prompting concerns regarding their environmental impacts and potential risks to human health. In recent years, the field of MNP research has witnessed the development and application of cutting-edge infrared (IR) spectroscopic instruments. This review focuses on the recent application of advanced IR spectroscopic techniques and relevant instrumentation to analyse MNPs. A comprehensive literature search was conducted, encompassing articles published within the past three years. The findings revealed that Fourier transform infrared (FTIR) spectroscopy stands as the most used technique, with focal plane array FTIR (FPA-FTIR) representing the cutting edge in FTIR spectroscopy. The second most popular technique is quantum cascade laser infrared (QCL-IR) spectroscopy, which has facilitated rapid analysis of plastic particles. Following closely is optical photothermal infrared (O-PTIR) spectroscopy, which can furnish submicron spatial resolution. Subsequently, there is atomic force microscopy-based infrared (AFM-IR) spectroscopy, which has made it feasible to analyse MNPs at the nanoscale level. The most advanced IR instruments identified in articles covered in this review were compared. Comparison metrics encompass substrates/filters, data quality, spatial resolution, data acquisition speed, data processing and cost. The limitations of these IR instruments were identified, and recommendations to address these limitations were proposed. The findings of this review offer valuable guidance to MNP researchers in selecting suitable instrumentation for their research experiments, thereby facilitating advancements in research aimed at enhancing our understanding of the environmental and human health risks associated with MNPs.Item Analysis of the vcgC gene in Vibrio vulnificus isolates from the Texas Coastal Bend region of the Gulf of Mexico(2023-05-12) Buck, Gregory W; Brumfield, LarReshia I; Giagnocavo, Stephanie Dudics; Perkins, Danielle S; Tortosa, Alvaro Ortola; Okuyemi, Tolulope B; Carbaugh, Joshua S; Planas Costas, Githzette M; Ramirez, Gabriel DVibrio vulnificus is a gram-negative, halophilic bacterium normally found in temperate marine and estuarine waters. The organism may enter wounds in the skin and cause sepsis or necrotizing fasciitis; the latter condition has a 50-60% mortality rate and may result in death or disfigurement within 4-6 days. Persons exposed to coastal flood waters during hurricanes may be at risk for this organism. The virulence-correlated gene, vcgC, is specific for clinical isolates of V. vulnificus, but the function of this locus remains unknown. This study used Polymerase Chain Reaction (PCR) and novel primers for vcgC not previously described to specifically identify V. vulnificus isolates from the Texas Coastal Bend region that may result in serious infections. Of the 28 isolates, four isolates could not be revived multiple times; crude lysates of the remaining 24 Vibrio vulnificus cultures were analyzed by PCR, and 19 were found to have amplicons of 428bp for vcgC. This study confirms the presence of the vcgC gene in V. vulnificus isolates from the Texas Coastal Bend region of the Gulf of Mexico.Item Anemonefish Genomics(2022) Salamin, Nicolas; Schunter, Celia; Monroe, Alison; Ryu, Taewoo; Ravasi, TimothyAnemonefish consists of 30 species and are likely the most recognizable fishes to the public due to their unique colour patterns, easy captive breeding, and the animation film Finding Nemo. They are also important species to biologists owing to their symbiotic relationship with anemones as well as sequential hermaphroditism and hence serve as emerging model organisms in ecology, evolution, and development. The latest advancements in high-throughput sequencing technologies and bioinformatic analysis have facilitated studies in anemonefish research. In this chapter, we first show the recent genomics studies that unveil the genomic architecture and underlying evolutionary processes in anemonefish. We also cover how state-of-the-art transcriptomic and proteomic techniques have been utilized to capture and uncover the fundamental molecular mechanisms driving dynamic changes in biological processes throughout development and under various environmental changes.Item Anthropogenic effects on the marine environment adjacent to Palmer Station, Antarctica(Cambridge, 2021-12-07) Palmer, Terence A.; Klein, Andrew; Sweet, Stephen; Montagna, Paul; Hyde, Larry; Wade, Terry; Pollack, Jennifer BeseresLocalized contamination from research-related activities and its effects on macrofauna communities in the marine environment were investigated at Palmer Station, a medium-sized Antarctic research station. Relatively low concentrations of polycyclic aromatic hydrocarbons (PAHs; 32–302 ng g-1) and total petroleum hydrocarbons (TPHs; 0.9–8.9 μg g-1) were detected in sediments adjacent to the sewage outfall and pier, where most human activities were expected to have occurred, and at even lower concentrations at two seemingly reference areas (PAHs 6–30 ng g-1, TPHs 0.03–5.1 μg g-1). Elevated concentrations of PAHs in one sample taken in one reference area (816 ng g-1) and polychlorinated biphenyls (353 ng g-1) and dichloro-diphenyl-trichloroethane (3.2 and 25.3 ng g-1) in two samples taken adjacent to the sewage outfall indicate spatial heterogeneity of localized sediment contamination. Limpet (Nacella concinna) tissues collected adjacent to Palmer Station had high concentrations of PAHs, copper, lead, zinc and several other metals relative to outlying islands. Sediment and limpet tissue contaminant concentrations have decreased since the early 1990s following the Bahía Paraíso spill. Natural sediment characteristics affected macrofaunal community composition more than contamination adjacent to Palmer Station, presumably because of the low overall contamination levels.Item The art of otolith chemistry: Interpreting patterns by integrating perspectives(CSIRO Publishing, 2019-01-21) Walther, BenjaminThe ability to obtain high-resolution chemical profiles across otoliths has expanded with technological advancements that prompted an explosion of data from diverse taxa in coastal, marine and freshwater systems worldwide. The questions pursued by most otolith chemists fall broadly into six categories: identifying origins, tracking migration, reconstructing environments, quantifying growth or physiology, validating ages and assessing diets. Advances in instrumentation have widened the periodic table of otolith elements, and two-dimensional mapping has further illuminated spatial heterogeneity across these complex structures. Although environmental drivers of observed elemental signatures in otoliths are often assumed to be paramount, multiple intrinsic and extrinsic factors can disrupt simple relationships between an element and a single environmental parameter. An otolith chemical profile is not a direct photograph of an environment, but rather an impressionistic image filtered through the multifaceted experiences of the fish itself. A ‘signal-to-noise’ approach that assesses the relative magnitudes of variation from intrinsic and extrinsic factors on chemical profiles may be a promising way to resolve the factor of interest against the ‘noise’ of others. A robust appreciation of environmental drivers, physiological regulation and calcification dynamics that affect the ability to effectively interpret otolith chemical patterns is necessary to drive the field forward.Item Assembling covalent organic framework membranes via phase switching for ultrafast molecular transport(2022-06-07) Khan, Niaz Ali; Zhang, Runnan; Wang, Xiaoyao; Cao, Li; Azad, Dr Chandra Sourabh; Fan, Chunyang; Yuan, Jinqiu; Long, Mengying; Wu, Hong; Olson, Mark; Jiang, ZhongyiFabrication of covalent organic framework (COF) membranes for molecular transport has excited highly pragmatic interest as a low energy and cost-effective route for molecular separations. However, currently, most COF membranes are assembled via a one-step pro cedure in liquid phase(s) by concurrent polymerization and crystallization, which are often accompanied by a loosely packed and less ordered structure. Herein, we propose a two-step procedure via a phase switching strategy, which decouples the polymerization process and the crystallization process to assemble compact and highly crystalline COF membranes. In the pre-assembly step, the mixed monomer solution is casted into a pristine membrane in the liquid phase, along with the completion of polymerization process. In the assembly step, the pristine membrane is transformed into a COF membrane in the vapour phase of solvent and catalyst, along with the completion of crystallization process. Owing to the compact and highly crystalline structure, the resultant COF membranes exhibit an unprecedented per meance (water ≈ 403 L m−2 bar−1 h−1 and acetonitrile ≈ 519 L m−2 bar−1 h−1 ). Our two-step procedure via phase switching strategy can open up a new avenue to the fabrication of advanced organic crystalline microporous membranes.Item Assess nonpoint source nitrogen contribution to the Texas Coastal Zone from septic systems(2022-09-30) McMullan, Esme; Zhang, Lin; Bonaiti, GabrieleThe goal of this project was to quantify and compare the amount of nitrogen (NH4 +, NO3 - , and NO2 - ) released into water bodies near Corpus Christi, Texas from wastewater treatment plants and septic systems in the surrounding communities. Sample collection began in November 2019 and carried on until September 2021, although it was interrupted during the height of the pandemic in spring of 2020. The sampling occurred at five different wastewater treatment plants ([WWTPs], Oso, Kingsville, Rockport, Portland, and Whitecap) as well as seven different septic systems in Corpus Christi (Oso), Kingsville, Portland, and Rockport near the WWTPs so that the nitrogen loading of these two different sources of treated effluent could be meaningfully compared. Effluents from WWTPs and on-site septic systems are sources of the nutrients responsible for aquatic nutrient pollution, releasing nitrate (NO3 - ), nitrite (NO2 - ), and ammonium (NH4 +) into local bodies of water, which could lead to eutrophication and hypoxia. Two different sources of effluent were sampled during this study: wastewater treatment plants (WWTP) and septic systems. Both WWTPs and septic systems separate solid waste from liquid wastewater, treat the wastewater, then discharge this cleaned effluent back into the natural environment; however, WWTPs serve a much larger area than septic systems, which collect and treat wastewater from a single home. Each WWTP and septic system may have different methods of treating wastewater and removing excess nutrients, if they are required to. This study detected significant levels of NO3 - , NO2 - , and NH4 + in bodies of water that served as reservoirs for effluents released by the septic systems and WWTPs. This suggests that further N removal processes would be needed if lower nitrogen concentrations in treated effluents were desired. Rockport WWTP is the only WWTP studied in this project that has a dedicated N removal process, which incorporates an anoxic tank and discharged the less N per day than other WWTPs studied in this project. The N released by Rockport WWTP was about 50% of the estimated N loading from combined onsite septic systems located in the same county. This suggests that N removal technique employed by WWTP is effective in nitrogen reduction, and N removal techniques should be employed by both WWTPs and septic system to reduce anthropogenic N contribution to local bodies of water.Item Assessing the ducting phenomenon and its impact on GNSS radio occultation refractivity retrievals over the Northeast Pacific Ocean using radiosondes and global reanalysis(2023-07-24) Winning Jr., Thomas E.; Xie, Feiqin; Nelson, Kevin J.In this study, high-resolution radiosondes from the MAGIC field campaign and ERA5 global reanalysis data are used to assess the elevated ducting layer characteristics along the transect over the northeastern Pacific Ocean from Los Angeles, California to Honolulu, Hawaii. The height of the planetary boundary layer (PBLH) increases as the strength of the refractivity gradient and resultant ducting decrease from east to west across the analysis transect. The thickness of the ducting layer remains remarkably consistent (∼110 m) in the radiosonde data. On the other hand, the ERA5 generally resolves the ducting features well but underestimates the ducting height and strength especially over the trade cumulus region near Hawaii. A simple two-step end-to-end simulation is used to evaluate the impact of the elevated ducting layer on RO refractivity retrievals. A systematic negative refractivity bias (N-bias) below the ducting layer is observed throughout the transect, peaking approximately 70 meters below the PBL height (−5.42 %), and gradually decreasing towards the surface (−0.5 %). Further, the underestimation of the N-bias in the ERA5 data increases in magnitude westward and while the correlation of the N-bias with the minimum gradient and sharpness are all strong; there is no evidence of zonal dependence.Item An assessment of hydrogen sulfide intrusion in the seagrass Halodule wrightii(2022-09-28) Rubiano-Rincon, Sebastian; Larkin, PatrickHydrogen sulfide (H2S, “sulfide”) is a naturally occurring component of the marine sediment. Eutrophi cation of coastal waters, however, can lead to an excess of sulfide production that can prove toxic to seagrasses. We used stable sulfur isotope ratio (δ34S) measurements to assess sulfide intrusion in the seagrass Halodule wrightii, a semi-tropical species found throughout the Gulf of Mexico, Caribbean Sea, and both western and eastern Atlantic coasts. We found a gradient in δ34S values ( 5.58 0.54‰þ 13.58 0.30‰) from roots to leaves, in accordance with prior observations and those from other species. The results may also represent the first values reported for H. wrightii rhizome tissue. The presence of sulfide-derived sulfur in varying proportions (15–55%) among leaf, rhizome, and root tissues suggests H. wrightii is able to assimilate sedimentary H2S into non-toxic forms that constitute a significant portion of the plant’s total sulfur content.Item Assessment of parental beno[a]pyrene exposure-induced cross-generational neurotoxicity and changes in offspring sperm DNA methylome in medaka fish(2022-05-27) WAN, Teng, Miles; AU, Wai Ting Doris; MO, Jiezhang; Chen, Lianguo; Cheung, Kwok-Ming; KONG, Yuen Chong Richard; Seemann, FraukePrevious studies have revealed that DNA methylation changes could serve as potential genomic markers for environmental benzo[a]pyrene (BaP) exposure and intergenerational inheritance of various physiological impairments (e.g. obesity and reproductive pathologies). As a typical aromatic hydrocarbon pollutant, direct BaP exposure has been shown to induce neurotoxicity. To unravel the inheritance mechanisms of the BaP-induced bone phenotype in freshwater medaka, we conducted whole-genome bisulfte sequencing of F1 sperm and identifed 776 differentially methylated genes (DMGs). Ingenuity pathway analysis revealed that DMGs were signif cantly enriched in pathways associated with neuronal development and function. Therefore, it was hypothesized that parental BaP exposure (1 μg/l, 21 days) causes offspring neurotoxicity. Furthermore, the possibility for sperm methylation as an indicator for a neu rotoxic phenotype was investigated. The F0 adult brains and F1 larvae were analyzed for BaP-induced direct and inherited toxicity. Acetylcholinesterase activity was signifcantly reduced in the larvae, together with decreased swimming velocity. Molecular analysis revealed that the marker genes associated with neuron development and growth (alpha1-tubulin, mbp, syn2a, shh, and gap43) as well as brain development (dlx2, otx2, and krox-20) were universally downregulated in the F1 larvae (3 days post-hatching). While parental BaP exposure at an environmentally relevant concentration could induce neurotoxicity in the developing larvae, the brain function of the exposed F0 adults was unaffected. This indicates that developmental neurotoxicity in larvae may result from impaired neuronal devel opment and differentiation, causing delayed brain growth. The present study demonstrates that the possible adverse health effects of BaP in the environment are more extensive than currently understood. Thus, the possibility of multigenerational BaP toxicity should be included in environmental risk assessments.