Using Corpus Linguistics to Investigate Approaches to Oyster Fishery Management Across Political Boundaries

Oysters are critical resources that filter water, generate habitat, and safeguard shorelines in coastal and marine ecosystems. Balancing conservation needs with sustainable oyster fisheries is essential for maintaining oyster health and stocks. In the U.S. Gulf of Mexico, oyster resources are managed by five states (Texas, Louisiana, Mississippi, Alabama, and Florida), each with unique approaches and priorities. This study analyzes the most current oyster management guidance document for each state using corpus linguistics techniques—including keyword and concordance analyses—to identify linguistic distinctions that reflect state-specific management priorities. Findings reveal that Florida’s document is the most distinctive, emphasizing oyster stressors and habitat. Louisiana’s document reflects its role as a major oyster producer. Mississippi’s document uniquely highlighted aquaculture as a strategy for recovering from environmental stressors. The theme of oyster restoration is robust in Alabama’s 2021 document but absent in Texas’s 1988 document, highlighting temporal differences in management priorities. In addition, common themes such as state-specific oyster stressors emerged among the distinctions. These results demonstrate how management priorities vary across political boundaries and provide insights for improving regional coordination. This approach offers a framework that can inform natural resource management strategies in other contexts and in other regions globally

Corals in ocean acidification and the role of calcium ion homeostasis to maintain calcification

Coral calcification is essential to provide the structural foundation for coral reefs and is integral in supporting marine biodiversity reliant on reef ecosystems. The drivers for calcification in corals are undoubtedly highly complex and require several perspectives to identify vulnerabilities in the context of environmental change. Specifically, ocean acidification (OA) resulting from the rise of anthropogenic carbon dioxide (CO2) emissions poses a potential threat to the physiological mechanisms that drive calcification in corals. Therefore, this report goes beyond environmental seawater chemistry to examine the physiological mechanism of calcium ion homeostasis. Calcium's role in calcification physiology is well established, but how calcium homeostasis could shift under acidification has little been considered a significant driver in reduced calcification. Calcium is potentially the most actively transported substrate in coral calcification, though in high chemical abundance in seawater, corals are likely utilizing the most energy to concentrate calcium at the site of calcification. We argue for increased consideration of the calcium ion in the context of OA when identifying sensitivities. The concepts proposed here are justified through a combination of results from novel RAMAN spectroscopy and molecular work that provides insight into shifts in calcium homeostasis when exposed to acidification. We speculate that future work incorporating methodologies considering calcium dynamics in OA could benefit by narrowing in on what physiological mechanisms are potentially vulnerable. It is imperative that we identify what drives lower calcification in corals under OA to inform efficient directives in identifying species sensitivities to future climate change

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

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

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

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

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

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