2022 Spring Student Research Symposium Oral Presentation Materials
Permanent URI for this collectionhttps://hdl.handle.net/1969.6/90412
Browse
Browsing 2022 Spring Student Research Symposium Oral Presentation Materials by Issue Date
Now showing 1 - 20 of 30
- Results Per Page
- Sort Options
Item A preliminary assessment and subsequent data evaluation of socioeconomic indicators of water quality(2022-04) Kramer, Mary; Yoskowitz, DavidUrban and agricultural runoff, changes to land use patterns and other anthropogenic sources of pollution affect water quality. Water quality is a key factor in ecosystem health. While physical and ecological models of pollution have been widely used to determine water quality, there is a significant gap in the use of socioeconomic metrics in these models. Numerous studies have explored the effects and/or trends of impaired water quality on socioeconomic factors. However, less information is available on the impact of socioeconomic factors on surface water quality. This study conducted a literature review of commonly assessed human activity and socioeconomic variables associated with water quality and assessed the availability of data to quantify these variables. The intent of this review is to apply available evidence-supported data to two case studies in the Texas Coastal Bend: Baffin Bay and San Antonio Bay. From the literature, commonly used socioeconomic metrics include land use/land change, community type, demographics, and population density. Possible point sources of pollution that relate to socioeconomic factors identified were wastewater treatment facilities, stormwater drainage, mining and oil extraction operations, and product manufacturing/ chemical production. Furthermore, this presentation will provide a preliminary assessment of data sources, data gaps, and recommendations.Item Comparison of growth rates of larval Atlantic croaker collected near Corpus Christi and Galveston(2022-04) Weigand, Angelina; Geist, Simon; McAskill, Shannan; Bromschwig, MichelleDuring their early life stages, larval fish are vulnerable to a variety of physical, biological, and environmental processes. The ability of larval fish to successfully capture prey items affects their body condition, growth rates, and ultimately survivorship. Previous studies on the larval diets of M. undulatus collected from October to November 2017 at two distinct locations Galveston, TX and Corpus Christi, TX showed significantly different diets at the two locations at the family level taxonomic resolution of prey items. The goal of this study was to determine if the M. undulatus between the two locations also have a difference in condition and growth rates that may be related to differences in diets and localized prey availability. Larvae for this study were collected approximately two to two and a half months following Hurricane Harvey, which may have changed the water quality which affects the growth of larval fish. Therefore, this study will also assess differences in environmental parameters between the two locations to determine the potential effects of the Hurricane. For that otoliths were extracted from larval M. undulatus and use otolith increment growth analyses to investigate the differences in their growth rates. The samples were divided into different categories including catch date, size class, and catch site. The two size classes that the study focuses on are 5.0-6.99 mm and 7.0-8.99 mm. By extracting, mounting, polishing, and measuring the otoliths from the collected samples, we are able to determine the growth rate and the age of the fish and expect to see differences between locations that may be caused by diet differences and water quality.Item Corals in crisis: How temperature and nutrient fluctuations affect physiological responses of corals and their microbiome in Kāne’ohe Bay, Hawai’i(2022-04) Ruben, Zoe; Pinnell, Lee; Abdulla, Hussain; Turner, Jeffrey; Bahr, KeishaCoral reefs are the foundation to the social, cultural, and economic life in Hawai i; however, these reefs have not escaped the conditions that have ravaged coral reefs worldwide. Along the east coast of O ahu lies Kāne ohe Bay, which serves as a living laboratory with distinct difference in environmental gradients due to variation in circulation and residency times. Landward, there is a distinct gradient of cesspool presence and therefore a gradient of potential effluent intrusion and nutrient loading to these reefs. Together, these provide a unique opportunity to explore the impact of water quality and ongoing ocean warming on coral health, susceptibility and tolerance. This research investigates how temperature and nutrients influence the coral holobiont across a spatial and temporal environmental gradient. Pairs of known bleached/non-bleached corals were collected at two sites within Kāne ohe Bay which encompass this spatial gradient in temperature and nutrient influence. Corals were then subjected to experimental treatments (Control, Nutrient, Heated, Heated + Nutrient) for one month. Measurements of bleaching were collected at the beginning, middle, and end of the experiment and coral subsamples were collected at the beginning and end of the experiment for subsequent metagenomics analysis. I hypothesize that (A) coral subjected to a combined increase in temperature and nutrients will experience higher levels of bleaching and lower levels of survivorship, (B) historically non-bleached phenotypes will show higher levels of survivorship than their historically bleached counterparts, and (C) there will be an observed shift in microbial community composition across corals due to these stressors. If validated, these findings will support that coral bleaching susceptibility is manifested throughout the coral holobiont and the physiological response to stressors such as temperature and nutrient loading can be better understood and potentially mitigated, therefore supporting reef resiliency and restoration in the face of climate change.Item Large and fine-scale genetic structure of king snake eels (ophichthus rex) throughout the gulf of Mexico(2022-04) Chavez, Aline Trejo; O’Leary, Shannon; Cotton, Charles; Murwawski, Steve; Portnoy, David S.The king snake eel (Ophichthus rex), is a large, long-lived demersal predator and their distribution is limited to the Gulf of Mexico (GoM). King snake eels, like other ophichthids are data deficient, little is known about the O. rex biology. Eels were sampled throughout GoM (2011-17); eel tissues were prepared for sequencing using new molecular techniques resulting in robust ddRADseq SNP libraries. Genetic differentiation was estimated and new multidisciplinary approaches were used to explore large and fine-scale patterns of observed genetic connectivity. Previous studies of genetic connectivity in the Gulf of Mexico, have been limited to a few commercially important species and have been spatially limited to northern GoM (US). This study is unique, as it encompasses the entire species distribution and utilizes Gulf-wide fisheries-independent survey data (GoMRI 2011-2017). In this study we present evidence of large-scale population structure as reported in previous GoM connectivity studies and discuss potential drivers of fine-scale differentiation patterns within and among populations. Finally, this study explores potential implications for other fisheries- affected species and increases overall understanding of the underlying biology that drives observed patterns of genetic connectivity.Item Abundance of bottlenose dolphins (tursiops truncatus) in Texas coastal bend(2022-04) Wilkins, Allison; Orbach, Dara N.Bottlenose dolphins (Tursiops truncatus) are the only species of marine mammal residing in the Texas Coastal Bend and have been specifically identified as imperiled by the National Oceanic and Atmospheric Administration. It has been almost 40 years since research has been published on the local population of bottlenose dolphins. In recent decades, the Texas Coastal Bend has substantially expanded in industrial growth and the Port of Corpus Christi is the third largest port in crude oil exportation in the U.S.A. The Corpus Christi Shipping Channel is also undergoing continual dredging to widen and deepen the channel to attract more commercial and industrial developments. With increasing and rapid changes and associated threats, it is important to monitor the local population of bottlenose dolphins and quantify how they are impacted by anthropogenic disturbance to inform policymakers for conservation mitigation. The population abundance of dolphins inhabiting the Texas Coastal Bend was determined by counting the number of animals based on unique markings. Photographs were captured of the individually distinctive dorsal fins of dolphins from a research vessel during 45 survey days since 2018. Photographs were subjected to quality control checks, cropped, matched by a minimum of two researchers, and scored based on quality. Preliminary results show that the current population of bottlenose dolphins consists of over 1,300 individuals, indicating a substantial population growth from the 593 dolphins reported in 1983. Findings from this study and additional photo- identification surveys will provide insights on the stability of the population that can be used as baseline data for conservation, including if dolphins are year-round residents and frequently inhabit areas of high vessel traffic.Item Tracking bottlenose dolphin movement and behavior in the Corpus Christi ship channel(2022-04) Mills, Eliza; Orbach, Dara N.Port Corpus Christi and Port Aransas, Texas, have undergone considerable infrastructure and oil exportation growth over the past 40 years. As humans continue to transform and exploit these coastal marine habitats, understanding dolphin and vessel interactions in the area is vital to improve conservation and management practices. As dolphins increased diving intervals and avoidance behavior in the presence of vessels, protecting marine mammals in areas of high vessel activity is urgent. To test the hypothesis that the movement patterns and behaviors of free-swimming bottlenose dolphins (Tursiops truncatus) are altered by vessel presence and size near Port Aransas, a shore-based digital theodolite is being used. Dolphin behavioral state and movement are analyzed in response to vessel activity. Distance between dolphin positions and habitat features are being calculated in ArcGIS Pro. Large vessels may elicit social and travel behavioral states as dolphins rode on the bows of most large tankers and cargo carriers. Dolphins mill and forage along channel banks and near the ferry crossing, suggesting that physical structures of concrete seawalls and mixing currents from vessel activity are utilized by dolphins to capture prey. In the morning and afternoon, dolphins oriented along the channel perimeter against the current flow with no positional changes in movement, indicating that tides may influence this population’s movement and behavior patterns. Understanding behavioral associations with diverse microhabitats in the Port Aransas area is crucial to conserve critical environments utilized by dolphins.Item Physiological stress and health of dolphins in the Texas coastal bend(2022-04) Guinn, Makayla A.; Orbach, Dara N.Common bottlenose dolphins (Tursiops truncatus) are an important bioindicator species of ecosystem welfare and sustainability and generate critical economic capital annually through ecotourism in the Texas Coastal Bend (TCB). The TCB stock of dolphins has specifically been identified as imperiled by the National Oceanic and Atmospheric Administration due to the number of anthropogenic and natural disturbances they encounter, and proactive monitoring of TCB dolphins is a current management priority. Recent economic growth has supported large-scale coastal infrastructure initiatives, including the imminent construction of desalination plants within the TCB. Because common bottlenose dolphins are highly vulnerable to salinity changes, which can lead to infectious disease and mortality, it is critical to determine baseline health and stress levels before the construction of desalination plants in order to monitor physiological changes post- construction and to inform policymakers of environmental impact. In this study, we will assess physiological stress and health conditions in TCB bottlenose dolphins using a novel approach system. A drone will be flown over dolphins to measure the prevalence and severity of skin lesions, which are an indicator of compromised epidermal integrity, for the first time from an aerial perspective. Blubber samples will be collected from the same dolphins using a remote biopsy technique to measure stress hormone levels; this study will be the first to validate aldosterone in the blubber of bottlenose dolphins. The baseline health and stress data collected will be used to directly measure bottlenose dolphin susceptibility to environmental disturbances and will assist in the preservation of marine life in the TCB.Item Fingerprinting circulating tumor cell with characteristic membrane viscoelasticity by atomic force microscopy(2022-04) Lopez, Kimberly; Tamuno, Sophia; Brzezinski, Molly; Martin, Leisha; Xu, Wei; Sheng, JianAtomic Force Microscopy (AFM) is a powerful tool that can resolve nanoscale cell surface features (e.g. re- ceptors, channels) as well as perform the mechanical characterization of living cells and tissues. Anecdotal observations suggest that metastasized tumor cells bear their phenotypical “telltale” signatures in their mem- brane characteristics, i.e prostate cancer cells are often stiffer and more elastic than breast cancer. In this talk, we present a new methodology allowing us to quantify mechanical properties of cells through force- deformation relations (F-D curves) by nano-indentation, as well as develop a novel mathematical framework to quantify cell membranes’ viscoelasticity by performing Ting’s integral over F-D measurements to differen- tiate cancer phenotypes. We have developed a custom-made flow cell that enables simultaneous microscopic observation and AFM experimentation. Three cell lines, prostate cancer (PC3), breast carcinoma (T47D), and lung a-carcinoma (A549), are used for this kernel study. Cells are split once reaching a confluence of 70% and a 10% dilution of cells are plated on 12 mm diameter wafer. After 24-hour growth, the plated slides are transferred to in-house flow cell containing the corresponding culture medium. With an integrated LED illuminator sealed within a polydimethylsiloxane matrix underneath the wafer, simultaneous observation of live cells can be achieved by an integrated upright microscope. Indentation measurements are conducted with a “wet” AFM. Gold coated probes (k=0.03N/m) are used to allow measurement on soft cell membrane. Differing from past studies, we probe the membrane with large indentation. Standard Linear Solid model are fitted over measurements to obtain viscoelasticity parameters. Preliminary results show distinctive hys- teresis between loading and unloading of the membrane. It is also found that multi-power law model is more suitable for cancer characterization. Model parameters of three phenotypes show clear distinction and great potential to develop membrane viscoelasticity as a biomarker for cancer cell diagnostics and characterization.Item A coral’s true colors: Understanding color hues to assess coral health and welfare(2022-04) Herrera, Gabriella; Good, Alexandra M.; Hirota, Alexander; Razal, Catherine; Gaertner, Nicole; Sefcik, Justin; Gilbert, Jesse; Bahr, Keisha D.Coral reefs are one of the most biodiverse and productive ecosystems on Earth and various methods are utilized to monitor and assess coral health. But there is not a standardized method for quantifying coral health for corals held in captivity in zoos and aquariums. Therefore, a health assessment card using coral color to non-invasively monitor coral health was developed with the Texas State Aquarium (TSA). To quantify coral health, individual corals of each species were photographed in a controlled environment to develop color profiles. Simultaneously, nondestructive measurements of “health” were assessed using Pulse- Amplitude Modulation Fluorometry. These photosynthetic efficiency measurements determine how efficiently the symbiotic algae provides energy to the coral host. This project successfully corresponded photosynthetic efficiency to coral color to develop a Coral Health Assessment Card for all species at TSA. By implementing a standardized assessment of coral health, TSA can effectively and rapidly assess the health of their corals improving overall coral wellness. Consequently, the results of this work support TSA’s mission to support wildlife conservation by promoting education and conservation of coastal and marine ecosystems through their interactive exhibits.Item An innovative approach to improving artificial insemination success(2022-04) Rich, Jacquline; Cowart, Jonathan; Orbach, DaraArtificial insemination is an important tool for conservation of endangered species and is highly reliant on access to high-quality sperm. Unfortunately, artificial insemination has had mixed success in different species, which may be due to collection and insemination of poor-quality sperm. Therefore, development of a novel technique to promote ejaculation of high-quality sperm is necessary to improve the success of future conservation efforts through artificial insemination. The purpose of this study is to develop an innovative tool that will function to improve the quality of sperm at the time of collection from animals in managed care. This biomimetic artificial vagina (BAV) is the first artificial vagina designed to mimic the natural shape and elasticity of biological tissue. Our BAV is designed to collect ejaculates from common bottlenose dolphins (Tursiops truncatus), which exhibit complex genital morphologies that have coevolved between the sexes. We hypothesize that the morphology of the vagina may play a role in stimulating the penis during ejaculation and will result in the production of higher quality ejaculates compared to traditional manual collection techniques. BAVs are created by coating vaginal molds made from post-mortem female dolphins with a soft, skin-like silicone. Ten adult male common bottlenose dolphins housed at aquaria around Florida and Texas are currently being trained to ejaculate into the BAV. We will assess sperm quality through examining the morphology and movement patterns of the sperm using computer-assisted sperm analysis software. The integrity of the sperm will be assessed using basic histochemical and microscopy techniques. We will compare the properties of the sperm collected using the BAV with sperm collected using traditional collection techniques to determine the impact of collection method on sperm quality. Our research has wide applications to conservation of terrestrial and marine endangered species through improving artificial insemination success.Item Use of multilinear regression for prediction of PH and aragonite saturation in the northwest Gulf of Mexico(2022-04) Jundt, EvaLynn; Hu, Xinping; Barbero, LeticiaThe Gulf of Mexico (GOM) is home to large shellfish populations, and the northernmost tropical coral reefs in the contiguous US. Despite this, the progression of Ocean Acidification (OA) in the GOM is still poorly understood as historical carbonate chemistry measurements are scarce. Based on carbonate chemistry and hydrographic data collected from 2007, 2017, and 2021, we derived multilinear regression models built upon relationships between commonly measured hydrographic properties (salinity, temperature, pressure, depth, or oxygen) and aragonite saturation state (Ωaragonite) and pH. The resulting models robustly predict Ωaragonite with R2>0.92, RMSE<0.07 and pH with R2>0.66, RMSE<0.30 for four different scenarios including different subsets of the data based on area and depth.Item Characterizing a live shear-resistant (SR-) biofilm and its interaction with substrates of varying energy landscapes by digital holographic microscope in eChip microcosm(2022-04) Yi, Wenjun; Jalali- Mousavi, Maryam; Sheng, JianRecent studies reveal that biofilm can develop under severe flow shear (e.g. >10,000 s-1) and eventually becomes resistant to shear erosion. Additional anecdotal evidence suggests clear correlation between biofilm structure and its underlying substrate energy landscapes. In this study, we are to investigate systematically the effects of these two environmental factors on formation of SR-biofilm. Here, we present experimental techniques that combine a long-term ecology-on-a-chip (eChip) milli-/micro-fluidic platform to grow a live SR-biofilm and a digital holographic microscope (DHM). The newly improved eChip platform not only provides long-term well controlled environments to a live SR-biofilm but also allow DHM to track thousands of individual bacteria as they interact with the substrate. New milli-fluidics also enables the interchange of substrates (bottom wall) containing different energy landscapes (e.g. alternating hydrophilic-hydrophobic patterns). Model bacteria include E.coli.(AW405), P. aeruginosa (PAO1) and its 12 mutants. Apart from homogeneous hydrophobic and hydrophilic substates, six patterned substrates (i.e. hydrophilic micro-patches, microscale squares and stars, of 20um, 50um, 100um over hydrophobic background) are used. Interactions of bacteria with these substrates are conducted under two shear flow rates (0 &10ul/min). During each experiment, bacteria will be cultured in eChip platform and flow over the patterned substrates for observation. Thousands of individual bacteria are tracked simultaneously in 3D over 20min at 14.5 frames per seconds at 20X and subsequently 3D trajectories, from which changes of cell motility (swimming speed, reorientation motility, and their translational/angular dispersions) as well as their attachment rates, will be obtained. In this talk, we will first present the novel microfluidic approach and robust digital holography technique (recording & analysis) in measuring microbial motilities/particle mobilities, then followed by a kernel study of P. aeruginosa in quiescent fluid interacting with substrates.Item Comparing diversity of estuarine-dependent nekton between Aransas Pass and Packery Channel inlets(2022-04) Kuntz, Joseph; Coffey, Daniel; Kaiser, Jeffrey; Williams, Jason; Stunz, GregoryTidal inlets play an essential role in estuarine-dependent nekton recruitment by providing access to nursery habitats (e.g., seagrass meadows) from spawning grounds in the Gulf of Mexico. The Corpus Christi Bay region includes Aransas Pass, a historically large inlet, and Packery Channel, a smaller natural tidal inlet permanently reopened in 2005. The purpose of this study was to (1) determine whether there is a seasonal difference in species diversity between the Aransas Pass (large) and Packery Channel (small) inlets and (2) determine if the distance from the inlet has an effect on species diversity. Shannon diversity indices were calculated from juvenile nekton (fish, shrimp, and crab) species collected using epibenthic sled tows from eight seagrass meadow sites near Aransas Pass and four sites near Packery Channel across three primary recruitment seasons (fall, winter, and spring). There was no significant difference in species diversity between the Aransas Pass and Packery Channel inlet, though there was a significant difference among seasons. Diversity was significantly higher during the winter and spring recruitment seasons at both inlets compared to the fall. In addition, distance (2-10 km) from the inlet had no significant effect on species diversity regardless of the season. These findings demonstrate that despite differences in size and age, Aransas Pass and Packery Channel support equally diverse nursery habitats across a range of distances for estuarine-dependent nekton species.Item NOx source apportionment in a coastal urban air shed using stable isotope techniques(2022-04) Shealy, Kaiya; Felix, J. DavidNOx (NO + NO2) emission decreases urban air quality and its subsequent deposition can be a significant source of excess nitrogen loading to coastal waters. Photochemical reactions between volatile organic com- pounds, and NOx in the atmosphere creates ozone (O3). Previous studies suggest that the City of Corpus Christi is in a NOx limited zone, so an increase in NOx would lead to an increase in O3. The first step to NOx emission mitigation is to quantify the contributions of NOx sources. This study uses stable isotope techniques to measure point and nonpoint NOx sources in order to quantify three main NOx sources in the Corpus Christi air shed: vehicular, biogenic, and industrial sources. Each of these sources have unique iso- topic compositions or “source signatures”, specifically 15N-NOx values, which are different for each source and allow the use of isotope mixing models to determine source contribution. NOx and NO2 passive air samplers will be deployed at three City of Corpus Christi NOx and ozone monitoring stations each month for one year and the nitrogen and oxygen isotopic composition ( 15N, 18O) of each sample will be measured. The 15N-NOx value in ambient air, and the 15N-NOx values of the NOx sources, will be applied to a Bayesian isotope mixing model to quantify source contributions. Limited preliminary data suggests that vehicular emissions is the main contribution, followed by industrial emissions, then biogenic. Results will help aid in the creation of an ozone action plan for the City of Corpus Christi.Item Corals thriving in dynamic environments may hold key insights into future coral reefs(2022-04) Epps, Ashleigh; Bruce, Morgan N.; Gates, Maryssa; Fifer, James; Davies, Sarah W; Bahr, KeishaThe coastal waters of Texas have dynamic environmental conditions and are heavily influenced by anthro- pogenic stressors, which are not conducive for corals. However, cryptic coral species (Astrangia poculata and Oculina diffusa) have been documented in this ecosystem, particularly within manmade channels on jetty rocks connecting the Gulf of Mexico and Corpus Christi Bay. This research explored the strategies that these corals utilize to survive with varying fluctuations in environmental conditions. Extensive in-water-field surveys were conducted in Packery Channel over one year to 1) identify observed corals 2) biologically char- acterize observed corals, 3) document environmental variability, 4) quantify zooplankton abundance, and 5) conduct coral tissue stable isotope analyses. Physical environmental data (e.g., turbidity, temperature, salinity, etc.) was measured weekly during each season (e.g., winter, spring, summer, and fall). Additionally, plankton abundance and diversity measurements were assessed within each season at the highest tide and the lowest tide of the full moon cycle. Corals were collected seasonally (total n=64). Results of this work revealed the species present are Astrangia poculata and Oculina diffusa and that these corals utilize both heterotrophy and autotrophy year-round to withstand extreme environmental conditions including large temperature (9.4-31.5°C) and turbidity (0-95.3 NTU) ranges. Stable isotope analyses suggest heterotrophy to be the dominant feeding mechanism year-round and autotrophy secondarily. Specifically, autotrophic contribution is more prominent during the summer and fall seasons than in the spring and winter seasons which correlates with the environmental data fluctuating the least in the summer and fall. Understanding the nutritional sources of corals in extreme environmental conditions could provide insights into potential phenotypic plasticity and adaptability to anthropogenic influence. Therefore, corals thriving in dynamic environments could provide researchers with the insight they need to understand coral adaptation amid rapidly changing environmental conditions.Item Sinking/suspended particles and zooplankton interactions in eastern tropical north pacific oxygen deficient zone revealed by δ15n-amino acids(2022-04) Lee, Charlotte; Mnich, Alanna; Catala, Fernando Contreras; García de León, Francisco Javier; Sánchez-Velasco, Laura; Baca, Jesus; McMullan, Esme; Mcallister, Marysa; Tran, Dat; Shaws, Catherine; Altabet, Mark; Zhang, LinPhotosynthesis by phytoplankton at the surface ocean fixes atmospheric carbon dioxide into organic matters that sink to the deep ocean in the form of particles. The composition and flux of particles could be affected by microbial degradation and consumption and repackaging by zooplankton. Within the oxygen deficient zones (ODZs), the zooplankton abundance is greatly reduced and oxygen is absent as electron acceptors for aerobic degradation of organic matters. Elevated biomass of zooplankton was found just below the lower ODZ boundary, presumably due to the higher availability of sinking particles for feeding. However, there is a lack of observations that could establish the link between sinking/suspended particles and zooplankton in the ODZs. A better understanding of sinking/suspended particles and zooplankton dynamics through ODZs is essential for evaluating the carbon export to the deep ocean, as ODZ is expected to expand due to the current warming climate. Sinking/suspended particles and zooplankton samples were collected at the eastern tropical north Pacific ODZ (14N, 104W) at various depths in December 2020. 15N of phenylalanine ( 15NPhe) and glutamic acid ( 15NGlu), the canonical source and trophic amino acid, are analyzed to assess the N isotope baseline and trophic positions (TPGlu-Phe) of these samples. 15NPhe and 15NGlu of surface suspended particles were 3.50‰ and 10.57‰ respectively, yielding a TPGlu-Phe of 1.48 that indicates the input of both phytoplankton and zooplankton materials to the suspended particle pool. Little enrichment in 15N of Glu was found between the suspended particles collected from the surface and below the lower boundary of ODZ (~1‰). This suggests limited trophic processing of sinking particles through the ODZ before zooplankton disaggregates them into suspended particles below the ODZ, which is in agreement with the slower sinking flux attenuation rate previously observed in ODZs.Item Can a multi-metric bioassessment tool be used to assess faunal communities in tidal streams along the lower Texas coast?(2022-04) Neffinger, Lexie; Beseres Pollack, Jennifer; Palmer, Terry; Breaux, NatashaTidal streams are dynamic, transitional systems that provide key habitat to many ecologically and economically important species. Currently, the Texas Commission on Environmental Quality (TCEQ) monitors tidal streams in Texas using only physicochemical parameters and lacks a standardized biomonitoring protocol. To address this gap in management tools, a multi-metric index of biotic integrity (IBI) was created to assess the condition of tidal stream nekton and benthic macroinfauna assemblages along the lower Texas coast. By identifying biotic metrics that are differently sensitive to anthropogenic impairment, the IBI synthesizes complex biological data into a practical management tool. To create the IBI, 15 sites were classified as having high (reference) or low (test) anthropogenic impairment based on surrounding land-use land cover, watershed population density, and historical conventional parameter concentrations for each tidal stream. During 2020 and 2021, sites were sampled for nekton, via seine hauls, and benthic macroinfauna, via benthic cores. Water quality, conventional parameter, and habitat measurements were also assessed during these sampling periods. Results show distinction between reference and test communities based on multivariate analyses. IBI metrics were derived from historical IBI studies and community analyses based on their ability to discriminate between test and reference conditions. Selected metrics included abundance of certain nekton taxa, abundance and biomass of benthic macroinfauna taxa, measures of diversity, and faunal functional groups. Refinements to the IBI should consider further regionalization based on coastal climate zone, assessing multiple sites per stream along the upstream-downstream salinity gradient, and incorporating long- term monitoring data. Once validated, the tidal IBI will enhance the TCEQ’s monitoring and management program by providing a standardized protocol to evaluate the biological communities in tidal streams and identify areas most in need of management attention.Item Texas tortoise task force: Collaborative networks to increase surveillance of disease in tortoises(2022-04) Tleimat, Jacquelyn; McCracken, ShawnTexas tortoises are the only North American tortoise not receiving federal protection and due to life history traits of low fecundity and limited dispersal they are particularly susceptible to anthropogenically-mediated decline, such as the oil and gas exploration throughout their range. Not only do these disturbances fragment the habitat of the Texas tortoise and restrict their range, but they may also suppress immune function increasing their susceptibility to disease. Upper respiratory tract disease (URTD) has been detected in all desert tortoise species and may cause morbidity and mortality in infected individuals. However, there is limited data on the presence of URTD in Texas tortoises and whether anthropogenic stressors or biological factors influence disease dynamics, hindering development of informed management strategies and actions. Therefore, we propose to 1) test for presence of URTD casual agents across the range of the Texas tortoise in the U.S.A. and 2) assess whether tortoises are more susceptible to URTD based on biological characteristics and anthropogenic stressors. To ensure our survey efforts are as widely representative as possible, we have established a network of biologists and citizen scientists to aid in our efforts. We have created an outreach and communication system with protocols for submitting observation data and assistance with obtaining biological samples. We will collect blood samples from Texas tortoises and send plasma samples to test for both URTD causal agents (Mycoplasma agasizzi and M. testudineum). We will further collect geographic variables, such as distances to oil/gas operations and distances to road, biological data (age, sex, size, any clinical URTD signs) to understand if certain anthropogenic stressors increase the prevalence of URTD. This knowledge will aid in relocation efforts of Texas tortoises in proximity to oil/gas operations and increase our understanding of disease prevalence in the species.Item Holistic investigation of a recurrent aureoumbra lagunensis brown tide bloom: Water quality parameters and microbial consortia(2022-04) Bachand, Paxton; Powers, Nicole; Haye, Kenneth C.; Pinnell, Lee; Tominack, Sarah; Turner, Jeffrey; Wetz, Michael S.Aureoumbra lagunensis forms persistent brown tide algal blooms that disrupt ecosystem processes through light attenuation, decreased oxygen availability, and reduced sediment stabilization. These disruptions have negative, cascading effects on the ecology and economy of coastal regions. Nearly four decades of research has explored the environmental and anthropogenic drivers of A. lagunensis blooms, yet previous research has not explored a bloom’s microbiome. Here, we present a holistic study wherein we characterized the water quality parameters and microbial consortia associated with a recurrent brown tide bloom, utilizing nearby non-bloom waters as comparison. Bloom waters were characterized by higher oxygen, pH, salinity, water temperature, chlorophyll a, and organic nitrogen and carbon concentrations. Variation in algal cell con- centrations were explained largely through dissolved organic nitrogen, organic carbon, and oxygen. Several bacterial taxa were significantly more abundant in bloom samples: Alphaproteobacteria (Rhodobacterales; 8.41%), Gammaproteobacteria (Chromatiaceae; 2.11% & Alcanivoracaceaewere; 1.73%), and Cyanobacte- ria (Nostocales; 4.50%). Alphaproteobacteria and Gammaproteobacteria have the potential to mediate B-vitamin acquisition and supply of sulfur compounds, respectively, in addition to the supply of reduced carbon and nitrogen compounds through cyanobacterial bloom co-dominance. Additionally, conditionally rare taxa that comprised nearly 15% of the bloom community (𝑃 ℎ𝑦𝑐𝑖𝑠𝑝ℎ𝑎𝑒𝑟𝑎𝑒(2.02) may mediate organic compound degradation, vitamin acquisition, and algal pathogenesis. Collectively, these results confirm and expand understanding of bloom drivers and demonstrate that A. lagunensis blooms are colonized by a unique microbial consortium that likely plays a significant role in bloom dynamics. Although a small percentage of the bloom’s community, these low abundance organisms can contribute disproportionate effects to the ecosystem and therefore play an important role in regulating bloom dynamics.Item Characterizing landing locations in the shore-based recreational shark fishery in Texas(2022-04) Zapata, Hannah; Banks, Kesley; Smith, Jensen; Streich, Matthew; Coffey, Daniel; Stunz, GregorySharks are vital predators that keep the ocean ecosystems balanced; yet the potential impacts of improper handling during recreational shark fishing can increase their vulnerability. Successful conservation includes the education and implementation of proper handling practices, which are known to greatly influence the survival of sharks after release. However, factors associated with handling practices in the shore-based recreational fishery, such as landing locations along the surf-beach gradient, have not been well studied. Texas has one of the largest shore-based shark fisheries in the United States and catch-and-photo release tournaments like Texas Shark Rodeo (TSR), provide a unique opportunity to collect long-term data on sharks landed in this fishery. The purpose of this study was to characterize landing locations of sharks in the recreational fishery to help inform mortality after release. From photos submitted by TSR by participating anglers, landing locations, which may serve as a surrogate metric for air exposure time, were classified into three different categories based on the sharks’ gill position in relation to the waterline: (1) shark landed on dry sand (no water near the gills); (2) shark landed in the surf zone (gills might be somewhat aerated with wave action); and (3) shark landed mostly in the water (gills mostly underwater and aerated). A total of 8,697 landed shark photos were submitted to TSR from 2014-2021, of which 36.2% were landed on dry sand, 60.5% were in the surf zone, and 3.3% were landed with gills remaining mostly underwater. The relatively high percentage of sharks landed on dry sand may increase shark mortality after release. These findings have important implications for conservation-oriented organizations like TSR, that encourage the best catch-and-release practices to maximize shark survival and highlight the need for accurate mortality estimates based on landing location.