Award: OCE-1333633

Coastal ecosystems carry tremendous economic value, control fluxes of organic carbon on a global scale, and are increasingly vulnerable to climate change and environmental degradation in general. Our research investigated the origins and transformations of riverine and estuarine soluble organic matter, which is the base of the microbial foodweb and captures significant changes in the landscape through compositional changes. We sought to understand the controls on any potential detrimental impacts to these systems, including changes in nutrient runoff as it relates to primary production, changes in hydrologic management, changes in plant succession on the landscape that can result from climate change or fire, as well as changes in overall hydrology related to climate change. The approaches relied on experimental work to develop and calibrate specific biomolecules and to capture microbial and photoxidation degradation pathways, and on field work to capture biochemical conditions along a salinity gradient in the San Francisco Bay Estuary in three seasons. The molecular work was further extended to include novel analytical and automated mass spectral data-processing tools recently developed in the medical field for tracking small metabolites. The unique combination of molecular tracers, optical measurements, and high-resolution mass spectroscopy allow for rare intercalibration of all these techniques on a single study. In addition to research, this project provided a highly collaborative research, training and learning environment for undergraduates, graduate students, and postdoctoral fellows at the University of California, Davis, Texas A&M Galveston, and Florida State University. Given the economic impact of coastal ecosystems to the Texas economy and recreational fisheries, results from this research was integrated into teaching materials and presented to local audiences. Last Modified: 12/21/2018 Submitted by: Karl Kaiser