Award: OCE-1654232

The project "CAREER: The Impact of Hydrologic State on CO2 Flux and Acidification in Subtropical Estuaries" led by Dr. Xinping Hu at Texas A&M University-Corpus Christi was carried out from May 1, 2017 to April 30, 2023, which included an one year non-cost extension. This project aimed to unravel hydrologic control on CO2 flux and acidification, examine multidecadal trends of estuarine CO2 partial pressure using historical data collected by a state agency, and explore the effect of climate change on estuarine carbon cycle. On the educational front, this project targeted the creation of a new course on estuarine and ocean acidification and collaboration with a Hispanic dominated public school on aquatic science education. Both sets of objectives were successfully achieved. Peer-reviewed journal publications funded by this project advanced the understanding of carbon cycling and ocean acidification in estuaries along a climate gradient in the northwestern Gulf of Mexico. In addition, these results not only filled a critical knowledge gap in global estuarine carbon budget estimates, but also shed light on the biogeochemical responses of estuaries due to climate change and human activities. This project involved field-intensive sampling on board small vessels, lab-based experiments and chemical analysis, statistical analyses of both historical and newly collected data, and mass balance modeling. A total of 12 peer-reviewed journal articles and one peer-reviewed book chapter were published, and 50% of these journal articles are trainee-led. Two of these articles were also featured on the websites of Ocean Carbon and Biogeochemistry and North American Carbon Programs. In addition, three Ph.D. dissertations and one MS thesis were produced fully or partially supported by this project. The educational activities brought awareness of ocean acidification to students of various levels, from sixth grade to graduate school, as well as the general public, as both the PI and his students were invited to present at local community workshops to discuss ocean acidification. The PI participated in educational activities at a local high school and a middle school on aquatic science and ocean acidification education. Throughout the project except during the COVID-19 caused disruptions, five undergraduate and four high school interns, seven of whom from underrepresented background, joined the PI?s lab to conduct summer research. These student interns continued pursuing STEM related studies and career paths. During the project period, the PI requested supplemental funding from the NSF program ?Non-Academic Research Internships for Graduate Students (INTERN)? and a graduate student took advantage of this opportunity to participate in an internship at a non-governmental organization. This CAREER award had significant impact on the PI?s career by supporting both his research and teaching endeavors. The award helped refine his approach to mentorship, as evidenced by the recognition of an Outstanding PhD Mentor Award; it also allowed him to be innovative in his teaching methods. The pedagogical improvements were reflected by high student evaluation scores over the past a few years. The PI was also awarded tenure during the project period. In summary, this project was successful in meeting the originally outlined research and educational objectives, and it had meaningful impact on the trainees from the PI?s high school interns to his Ph.D. graduates. The results from the research add important pieces to solving the puzzle of estuarine and coastal carbon cycle, and the education programs fostered an environment of learning, curiosity, and collegiality. Training students, particularly those from underrepresented backgrounds, was an important component of this project, and this project helped contribute to increased diversity in STEM. Last Modified: 06/04/2023 Submitted by: Xinping Hu