Texas A&M University – Corpus Christi
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Rodney James Mirabal's father
No full textA side view of Rodney James Mirabal's dad leaning on the back of his han
Bobby and Eddie Galvan preforming at Jazz Festival
No full textBobby and Eddie Galvan preforming at the Jazz Festival with a band on stag
Closer look of Rafael Galvan, Sr. as a Child
No full textUp Close look at the Skecthed Photograph of Rafael Galvan, Sr. as a Child wearing a ha
Autonomous UAVs navigation considering fixed/moving obstacles and no-fly-zones
No full textGeospatial Computer Science (GSCS) - Doctoral Student; Advisors: Dr. Jose Baca, Dr. Pablo RangelDrones Everywhere..!!!, Background - Drones Control, Single-Drone, Autopilot System: Drones fly autonomously through the programmed route, operator monitoring the drone during the flight time, no knowledge of other drones --> Hence most susceptible to collisions
An assessment of benthic condition in the Matagorda Bay System using a sediment quality triad approach
No full textA Thesis Submitted In Partial Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE in Marine Biology from Texas A&M University-Corpus Christi.The Matagorda Bay system is one of seven estuaries along the Texas coast. Once known to be an abundant and diverse ecosystem for marine organisms, however, there has been long-term decline in benthic abundance, biomass, and diversity in the Matagorda Bay System. One possible reason is contamination from municipal, agricultural, or industrial sources, which may be toxic to marine organisms. The purpose of this study was to examine sediment contamination to determine if pollution is a possible cause for ecosystem degradation. Degradation can be indicated by a decline in benthic integrity (i.e., diversity), decreased survival rates of organisms exposed to sediments, and sediment chemical contaminant concentrations over threshold limits. These methods form the Sediment Quality Triad (SQT), which is an interdisciplinary approach that includes contaminant concentrations as a measure of dose, a toxicity measure to assess biological effects, and benthic community diversity to indicate ecological effects. Twenty-four stations were sampled including historical, previously studied sites and sites suspected as having pollution induced degradation. The results revealed that there is contamination but only affecting localized areas in the estuary. The average means (ng/ g dry sediment) across all stations for DDT was 0.07, for PAH the average was 211.87, and for PCBs the average was 0.34. There were no contaminants above threshold limits for PCB, DDT and all but one PAH, but 46% of the stations had chemical detections over threshold limits for seven trace metals: arsenic, cadmium, mercury, copper, lead, nickel, silver, and dibenzo (a,h) anthracene. Mostly near river mouths, 16 of the 24 stations had moderate to high toxicity, and 17 out of the 24 stations had fair to low diversity. Toxicity was significantly correlated with diversity, whereas there were no correlations between sediment chemistry and toxicity or benthic metrics, signifying that there is no evidence that pollution is a problem estuary wide, rather it is localized. This indicates that this system is a multiple stressor system due to various natural influences (changes in temperature, dissolved oxygen, freshwater inflow, salinity) and contamination combined that are affecting benthic communities. With climate drastically changing and more industrialization increasing along the bay the benthic community will face constant declines and more salt or temperature tolerant species dominating. Therefore, focusing on the areas of concern with the most contamination and poor survival and diversity management plans (watershed and non-point sources) can be created to protect this regions ecosystem.Marine BiologyCollege of Scienc
Topic 4.5: Static and finals
No full textIn this module, you will learn about:
Static Class Attributes,
Static Methods,
Final Class Attribute
Linking shape to substance: Exploring morphometrics and geochemical records in eastern oyster shells from subtropical estuarine systems
No full textA thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Fisheries and MaricultureThis study aimed to investigate the resilience of eastern oysters (Crassostrea virginica) exposed to environmental stressors such as droughts and floods. The primary objectives were to assess the potential of geochemical records within oyster shells to discern past environmental variability and to evaluate the growth performance of these oysters in dynamic, subtropical estuarine systems subject to these major climactic events. Eastern oysters have been established as reliable bioindicators of water quality and records of their native habitats. Previous studies utilizing stable isotopes (?13C and ?18O) to track freshwater inflow patterns faced challenges due to multiple covarying factors. This study employed Ba/Ca ratios as an alternative proxy and examined their relationship with salinity. Notably, shell ?13C values demonstrated a remarkable match with estimated salinity values, highlighting the usefulness of this chemical proxy alone or in combination with ?18O for similar investigations. Despite their resilience, oyster growth performance can be adversely affected by environmental disturbances. Oysters from low, fluctuating salinity environments exhibited the greatest shell growth, followed by those inhabiting intermediate, then high, stable salinity environments. Which suggests that freshwater inflows following flood events positively influence estuarine functioning and oyster health, likely due to increased water turbidity, food availability, and reduced susceptibility to predation and disease. With projections of drier climates and variable precipitation patterns leading to more extreme temperature and salinity levels, eastern oysters may face greater growth limitations in the future. Therefore, understanding how environmental disturbances, including freshwater inflow dynamics, differentially impact oyster growth is crucial for the management and protection of this increasingly vulnerable keystone species.Fisheries and MaricultureCollege of Scienc
Identification of brush species and herbicide effect assessment in Southern Texas using an Unoccupied Aerial System (UAS)
No full textCultivation and grazing since the mid-nineteenth century in Texas has caused dramatic changes in grassland vegetation. Among these changes is the encroachment of native and introduced brush species. The distribution and quantity of brush can affect livestock production and water holding capacity of soil. Still, at the same time, brush can improve carbon sequestration and enhance agritourism and real estate value. The accurate identification of brush species and their distribution over large land tracts are important in developing brush management plans which may include herbicide application decisions. Near-real-time imaging and analyses of brush using an Unoccupied Aerial System (UAS) is a powerful tool to achieve such tasks. The use of multispectral imagery collected by a UAS to estimate the efficacy of herbicide treatment on noxious brush has not been evaluated previously. There has been no previous comparison of band combinations and pixel and object-based methods to determine the best methodology for discrimination and classification of noxious brush species with Random Forest (RF) classification. In this study, two rangelands in southern Texas with encroachment of huisache (Vachellia farnesianna [L.]Wight & Arn.) and honey mesquite (Prosopis glandulosa Torr. var. glandulosa) were studied. Two study sites were flown with an eBee X fixed-wing to collect UAS images with four bands (Green, Red, Red-Edge, and Near-infrared) and ground truth data points pre- and post-herbicide application to study the herbicide effect on brush. Post-herbicide data were collected one year after herbicide application. Pixel-based and object-based RF classifications were used to identify brush in orthomosaic images generated from UAS images. The classification had an overall accuracy in the range 83–96%, and object-based classification had better results than pixel-based classification since object-based classification had the highest overall accuracy in both sites at 96%. The UAS image was useful for assessing herbicide efficacy by calculating canopy change after herbicide treatment. Different effects of herbicides and application rates on brush defoliation were measured by comparing canopy change in herbicide treatment zones. UAS-derived multispectral imagery can be used to identify brush species in rangelands and aid in objectively assessing the herbicide effect on brush encroachment.This graduate research study was funded by the Department of Soil & Crop Sciences at Texas A&M University, College Station, TX, USA