Award: OCE-1658067

The vast ocean contains a diverse array of microorganisms that shape its chemistry. And despite its fluid nature, the ocean has structure in its physical, chemical, and biological properties. In this study, we investigated chemical and biochemical aspects of that structure in the Sargasso Sea, where chemical nutrients that can fuel microbial life are in such short supply that it induces competition for survival and appears to create chemical structure as a consequence. And because these processes change over large scales, 100s to 1000s of kilometers laterally, and very short scales over just a few meters or less vertically, we employed a novel robot to help us conduct this work. This robot, Clio, is a novel AUV we designed just for the purpose of studying processes like this. Clio is designed to facilitate ocean-basin and global-scale studies of ocean biochemistry, to move vertically through the water column with high precision, and specifically to return sensor data and samples from large swaths of the ocean ranging in depths from the surface to 6,000 m. This was Clio’s first operational field study. As part of this study, in June 2019, it completed its first large-scale ocean survey. In this study, we also used Clio to perform high-resolution observations with a narrow band of the upper ocean called the deep chlorophyll maximum, where microbial primary productivity and nutrient competition are most intense in places like the Sargasso Sea. Those samples were used to identify the biochemical structure within that zone, and Clio allowed us to observe these processes at resolutions that were not previously possible. This study investigated biochemical structure within the ocean at both fine and broad scales and also demonstrated a robotic oceanography approach for global-scale surveys of ocean biochemistry. This project provided many opportunities for graduate and postdoctoral students at the University of Texas Rio Grande Valley and our partner institutions to work with an exciting combination of ocean chemistry and robotics and participate in a process of technical innovation directed at advancing ocean science. This project also supported learning opportunities in graduate courses on environmental sensing and robotics through enhanced demonstrations and examples from real-world science applications and engineering, which is invaluable for communicating the process and principles to our students. Last Modified: 08/10/2022 Submitted by: John A Breier