Grant: Research Tools and Instruments

Marine ecosystems are becoming increasingly stressed by rising temperatures, ocean acidification and the decline in dissolved O2 in the ocean interior (ocean deoxygenation). These stressors will cause substantial global changes in the physical, chemical and biological environment, ultimately affecting the ocean's biogeochemical cycles and metabolism.******Optimal dissolved O2 concentrations are critical for the proper functioning of most marine ecosystems. Models predict a decline of 1-7% in the global ocean O2 inventory over the next century, and a spatial and temporal increase in O2 starved regions, the so-called O2 minimum zones (OMZs). These OMZs comprise 8% of the global ocean today, and have already expanded in various regions, mainly due to rising temperatures and increased waste run-off from our farms and cities. Indeed, some coastal areas experience extreme O2-starvation events regularly, producing “dead zones” that decimate marine fisheries and alter food web structures. ******To predict how further ocean deoxygenation will change ocean metabolism and alter nutrient and energy cycles, we need to understand the functioning and regulation of microbial metabolisms in O2-starved regions. Advanced omic technologies have allowed us to elucidate links between microbial functioning and environmental conditions, and have revolutionized our understanding of marine ecology and elemental cycling. However, global biogeochemical models still lack the rates of many fundamental processes that link marine microbes and their diverse metabolic potential (from omic' data) with oceanic biogeochemical gradients over space and time. ******Here we request infrastructure funding for developing and building an autonomous submersible profiling and incubation system to investigate in-situ microbial activity and function in O2-starved regions. This system is the first of its kind, and will allow us to a) collect samples for microbial omics studies, and for dissolved and particulate trace metal and nutrient analyses, and b) determine authentic metabolic rates at in-situ depths, with minimal perturbation and high temporal and spatial resolution.******This system will enable more accurate depictions of the structure and functioning of present and future OMZs ecosystems, as well as of the ramifications of ocean deoxygenation, including its effect on global warming (via the production and consumption of greenhouse gases such as carbon dioxide, methane and nitrous oxide), fisheries production and marine biodiversity. We will also provide training on state-of-the-art, standardized methodologies for sampling and processing of omic, physiological and biogeochemical samples for young oceanographers. This combined sampling approach?which includes physiology, omics, and biogeochemistry?is the holistic approach needed to identify community- or gene-based biomarkers to monitor and predict ecosystem function and biogeochemical cycles in a rapidly changing ocean.**