Vulnerability of Wetlands due to Projected Sea-Level Rise in the Coastal Plains of the South and Southeast United States

Coastal wetlands are vulnerable to accelerated sea-level rise, yet knowledge about their extent and distribution is often limited. We developed a land cover classification of wetlands in the coastal plains of the southern United States along the Gulf of Mexico (Texas, Louisiana, Mississippi, Alabama, and Florida) using 6161 very-high (2 m per pixel) resolution WorldView-2 and WorldView-3 satellite images from 2012 to 2015. Area extent estimations were obtained for the following vegetated classes: marsh, scrub, grass, forested upland, and forested wetland, located in elevation brackets between 0 and 10 m above sea level at 0.1 m intervals. Sea-level trends were estimated for each coastal state using tide gauge data collected over the period 1983–2021 and projected for 2100 using the trend estimated over that period. These trends were considered conservative, as sea level rise in the region accelerated between 2010 and 2021. Estimated losses in vegetation area due to sea level rise by 2100 are projected to be at least 12,587 km2, of which 3224 km2 would be coastal wetlands. Louisiana is expected to suffer the largest losses in vegetation (80%) and coastal wetlands (75%) by 2100. Such high-resolution coastal mapping products help to guide adaptation plans in the region, including planning for wetland conservation and coastal development

Stage and discharge prediction from documentary time-lapse imagery

Imagery from fixed, ground-based cameras is rich in qualitative and quantitative information that can improve stream discharge monitoring. For instance, time-lapse imagery may be valuable for filling data gaps when sensors fail and/or during lapses in funding for monitoring programs. In this study, we used a large image archive (>40,000 images from 2012 to 2019) from a fixed, ground-based camera that is part of a documentary watershed imaging project (https://plattebasintimelapse.com/). Scalar image features were extracted from daylight images taken at one-hour intervals. The image features were fused with United States Geological Survey stage and discharge data as response variables from the site. Predictions of stage and discharge for simulated year-long data gaps (2015, 2016, and 2017 water years) were generated from Multi-layer Perceptron, Random Forest Regression, and Support Vector Regression models. A Kalman filter was applied to the predictions to remove noise. Error metrics were calculated, including Nash-Sutcliffe Efficiency (NSE) and an alternative threshold-based performance metric that accounted for seasonal runoff. NSE for the year-long gap predictions ranged from 0.63 to 0.90 for discharge and 0.47 to 0.90 for stage, with greater errors in 2016 when stream discharge during the gap period greatly exceeded discharge during the training periods. Importantly, and in contrast to gap-filling methods that do not use imagery, the high discharge conditions in 2016 could be visually (qualitatively) verified from the image data. Half-year test sets were created for 2016 to include higher discharges in the training sets, thus improving model performance. While additional machine learning algorithms and tuning parameters for selected models should be tested further, this study demonstrates the potential value of ground-based time-lapse images for filling large gaps in hydrologic time series data. Cameras dedicated for hydrologic sensing, including nighttime imagery, could further improve results.The authors are grateful to the Platte Basin Timelapse project for providing the imagery used in this research. This research was supported by the U.S. Department of Agriculture—National Institute of Food and Agriculture NEB-21-177 (Hatch Project 1015698 to TG). Additional student support was provided by the University of Nebraska Research Council through a Grant-in-Aid grant funded through a gift from the John C. and Nettie V. David Memorial Trust Fund (to TG). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Interpreting biogeochemical processes through the relationship between total alkalinity and dissolved inorganic carbon: Theoretical basis and limitations

The marine carbonate system is influenced by anthropogenic CO2 uptake, biogeochemical processes, and physical changes that involve freshwater input and removal. Two frequently used parameters to quantify seawater carbonate system are total alkalinity (TA) and total dissolved inorganic carbon (DIC). To account for the physical changes, both TA and DIC are usually normalized to a reference salinity (i.e., nTA and nDIC), and then the relationship between nTA and nDIC is used to identify major biogeochemical processes that regulate the carbonate system, based on process-specific reaction stoichiometry. However, the theoretical basis of this interpretation has not been holistically examined. In this study, we validated this method under idealized conditions and discussed the associated assumptions and limitations. Furthermore, we applied this method to interpret field TA and DIC data from a lagoonal estuary in the northwestern Gulf of Mexico. Our results demonstrated that evaluating field data that encompass multiple stations and time periods could be problematic. In addition, various combinations of biogeochemical processes can lead to the same nTA–nDIC relationship, even though the relative importance of each individual process may vary significantly. Therefore, the stoichiometric relationship relying solely on TA and DIC data is not a definitive approach for uncovering dominant biogeochemical processes. Instead, measurements of process-specific parameters are necessary

Analysing micro- and nanoplastics with cutting-edge infrared spectroscopy techniques: A critical review

The 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.Funding for this research was provided by the Science Foundation Ireland (SFI)-Irish Research Council Pathway Programme Proposal ID 21/PATH-S/9290

Diffusive transport and coral calcification: A comparative study of branching and plating morphologies under ocean acidification

Corals are sessile animals that are subject to their environment and have various colony morphologies that influence their diffusive boundary layer, a thin layer of fluid surrounding the coral surface. Boundary layer dynamics are crucial for corals to acquire nutrients from the environment, supporting essential functions like calcification. However, we lack knowledge regarding individual and species-specific responses to changes in water column conditions and how these changes can affect boundary layer dynamics and, consequently, calcification. Therefore, the purpose of this study is to incorporate engineering concepts to investigate drivers and connections between the physical and chemical controls on coral calcification in current and future predicted ocean acidification (OA) conditions. The Hawaiian rice coral, Montipora capitata, is a polymorphic coral with multiple growth forms, including branching, plating, and encrusting. Six branching and plating M. capitata colonies were collected, and three of each morphology were exposed to two different water chemistry conditions for two weeks. Microsensor profiles were conducted to measure boundary layer thickness and water chemistry changes, and a flume was designed and constructed to control water flow. The findings show that the plating morphology has a thicker boundary layer than the branching morphology at the site of primary photosynthesis. Moreover, at the site of primary photosynthesis, a significant difference in surface oxygen (O2) concentrations was observed between the two morphologies in ambient conditions, implying increased O2 efflux rates and coral productivity from a branching morphology.Life SciencesCollege of Scienc

Mapping oyster habitat quality in Matagorda Bay through remote sensing-derived water quality datasets

Evaluating oyster habitat quality is gaining importance as populations face drastic global declines. Oyster Habitat Suitability Index (HSI) models evaluate habitat quality. Environmental and water quality indicators (WQIs) generate these oyster HSIs. In this study, we extracted WQIs from remote sensing data from 2014 to 2023 (Chapter II), then utilized these WQIs alongside other physical variables to produce five oyster HSI models for Matagorda Bay (Chapter III). These oyster HSIs generated used salinity, turbidity, temperature, depth, and water velocity to depict habitat quality. Remote sensing datasets offer a unique opportunity to observe spatial and temporal trends in WQIs, such as chlorophyll-a, salinity, and turbidity, across various aquatic ecosystems. In this study, we used available in-situ WQI measurements (chlorophyll-a: 17, salinity: 478, and turbidity: 173) along with Landsat-8 surface reflectance data to examine the capability of empirical and machine learning (ML) models in retrieving these indicators over Matagorda Bay, Texas, between 2014 and 2023. Models with greatest performance were applied to generate datasets for each WQI from 2018 to 2023. Five oyster HSI models were then generated over Matagorda Bay on both monthly and annual scales from 2018 to 2023. Each model utilized five physical parameters (e.g., model inputs), including salinity, turbidity, water temperature, depth, and water velocity. The developed approach provides a reference context, a structured framework, and valuable insights for utilizing empirical and ML models and Landsat-8 data to retrieve WQIs over aquatic ecosystems. Additionally, oyster HSI models generated from this study suggests locations of optimal, moderate, and unsuitable habitat based on long-term water quality in Matagorda Bay.Physical and Environmental SciencesCollege of Scienc

Spatial distribution and movement of Atlantic tarpon (Megalops atlanticus) in the northern Gulf of Mexico

Atlantic tarpon (Megalops atlanticus) are capable of long-distance migrations (hundreds of kilometers) but also exhibit resident behaviors in estuarine and coastal habitats. The aim of this study was to characterize the spatial distribution of juvenile tarpon and identify migration pathways of adult tarpon in the northern Gulf of Mexico. Spatial distribution of juvenile tarpon was investigated using gillnet data collected by Texas Parks and Wildlife Department (TPWD) over the past four decades. Generalized additive models (GAMs) indicated that salinity and water temperature played a significant role in tarpon presence, with tarpon occurrences peaking in the fall and increasing over the past four decades in this region. Adult tarpon caught off Texas (n = 40) and Louisiana (n = 4) were tagged with acoustic transmitters to characterize spatial and temporal trends in their movements and migrations. Of the 44 acoustic transmitters deployed, 18 of the individuals were detected (n = 16 west of the Mississippi River Delta and n = 2 east of the Mississippi River Delta). Tarpon tagged west of the Mississippi River Delta off Texas migrated south in the fall and winter into areas of south Texas and potentially into Mexico, while individuals tagged east of the delta migrated into Florida during the same time period, suggesting the presence of two unique migratory contingents or subpopulations in this region. An improved understanding of the habitat requirements and migratory patterns of tarpon inhabiting the Gulf of Mexico is critically needed by resource managers to assess the vulnerability of each contingent to fishing pressure, and this information will guide multi-state and multi-national conservation efforts to rebuild and sustain tarpon populations

Detection of astrophysical neutrinos at prospective locations of dark matter detectors

We study the prospects for detection of solar, atmospheric neutrino, and diffuse supernova neutrino background (DSNB) fluxes at future large-scale dark matter detectors through both electron and nuclear recoils. We specifically examine how the detection prospects change for several prospective detector locations [Sanford Underground Research Facility (SURF), SNOlab, Gran Sasso, China Jinping Underground Laboratory (CJPL), and Kamioka] and improve upon the statistical methodologies used in previous studies. Because of its ability to measure lower neutrino energies than other locations, we find that the best prospects for the atmospheric neutrino flux are at the SURF location, while the prospects are weakest at CJPL because it is restricted to higher neutrino energies. On the contrary, the prospects for the DSNB are best at CJPL, due largely to the reduced atmospheric neutrino background at this location. Including full detector resolution and efficiency models, the CNO component of the solar flux is detectable via the electron recoil channel with exposures of ∼103 ton-yr for all locations. These results highlight the benefits for employing two detector locations, one at high and one at low latitude

No humans here: Exploration in the digital age

No Humans Here connects a lineage between landscape painters of the Hudson River School and Impressionists with 3D landscape renderings from artists of the early digital age at the turn of the millennium – work that conveyed an era of unbound creativity before dwindling as populated by more and more people over time. This transition diluted elements of exploration and curiosity through actions of curation, control, and exploitation - to the point that what once was, no longer remains. The initial magic, mystery and creativity of those early explorers and inhabitants in this digital age are now merely artifacts. As global exploration began to reach its limits by the mid 20th century, the advent of digital space opened new lands to cultivate and explore. Artists of the 90’s began using modeling programs, beginning with natural landscapes and architecture as a launchpad for creativity, akin to previous eras of landscape art – with particular comparisons to the Hudson River School. These early digital worlds were void of human inhabitants due to the practical nature of digital space itself – that humans do not exist directly within, rather we (currently) interact externally – or their presence is only alluded to because of technical limitations. Unlike early American landscape paintings, users of this new medium were unconstrained by romanticized realism or religious fervor, rather, they were unbound by the vastness of their own imaginations, and fantasy and science fiction literary influences of the 20th century such as J.R.R Tolkien (1892-1973) and William Gibson (b. 1948). Additionally, the use of light, color, and visual-distortion brushstrokes of Impressionist landscape painting parallels the pixelated, low-resolution imagery of the early digital age. As of this writing, humans do not physically exist within digital space but use it as a gateway for mental projection. Digital space exists outside of time itself – records of its early history still live on online, untouched and without decay, while also constantly evolving through the present. No Humans here pays homages to the creativity of early 90's digital landscapes through nostalgia and reimagining, while also questioning hope, loss, and entropy of our digital futures.Art & DesignCollege of Liberal Art

Evaluating habitat provision by restored intertidal and subtidal oyster reefs in St. Charles Bay, Texas

Estuarine habitats, such as Crassostrea virginica oyster reefs, are critical to the resilience of coastal environments and provide many ecosystem services. To address declining oyster populations, oyster reef restoration has become a widespread management strategy to recover and restore lost ecosystem functions and biodiversity. While traditional restoration practices in Texas have focused on subtidal oyster reefs to ameliorate harvest impacts, there is growing interest in restoring intertidal reefs to maximize habitat benefits. This study evaluates the development of oyster populations and epifaunal communities on concurrently restored intertidal and subtidal oyster reefs in St. Charles Bay, TX, USA. In May 2022, 2.4 ha of oyster reef complex were restored in intertidal (0.5 m depth) and subtidal (1.5 m depth) areas using recycled oyster shells. Epifaunal and oyster dynamics were measured on the restored reefs and nearby natural reference reefs for 12 months (epifauna) and 18 months (oysters) following restoration. Results indicate distinct timelines for oyster population and epifaunal community development: restored subtidal reefs progressed faster, reaching peak oyster densities of 2203 ind. m-2 and similar epifaunal community composition to natural reference within 6 months post- restoration. In contrast, intertidal reefs reached peak oyster densities of 390 ind. m-2 at 12 months post- restoration with dissimilar epifaunal community compositions compared to natural reefs. Spat recruitment to restored intertidal and restored subtidal reefs occurred immediately following restoration, and oysters grew rapidly during the first 3 months, averaging 0.97- 0.95 mm d-1. Submarket size oysters (25- 75 mm) were observed on both restored intertidal and restored subtidal reefs just 1 month after restoration, and market size oysters (≥ 76 mm) occurred on the restored subtidal reefs within 6 months. Large quantities of drift algae were deposited on the restored intertidal reefs in August 2022 and persisted for 4- 6 months, which may have affected oyster and epifaunal recruitment and growth. On restored subtidal reefs, epifaunal densities, biomass, diversity, and community composition became similar to natural reference reefs within 6 months following restoration. On restored intertidal reefs, although epifauna diversity became similar to natural reefs within 12 months, epifaunal community composition remained distinct throughout the 18-month study period. The findings of this study offer important insights into key differences in restored intertidal and subtidal oyster reef development, making it possible to evaluate the ecological tradeoffs of restoration approaches and inform future restoration efforts.Physical and Environmental SciencesCollege of Scienc