Project: CAREER: Carbon, nitrogen, and oxygen biogeochemistry at the scale of a sinking marine particle

CAREER: Carbon, nitrogen, and oxygen biogeochemistry at the scale of a sinking marine particle

Sinking particles transport carbon from surface waters to the deep ocean. As particles sink, microorganisms transfer nutrients to and from the surrounding water. Microorganisms also use organic matter associated with particles as a source of energy. Together, the metabolism of microbes and physical processes control whether carbon is consumed or preserved in the ocean. Yet, the processes that occur at microscopic scales on particles remain poorly understood. This research will study the biogeochemical, physical, and ecological processes that influence sinking particles in the ocean. The project will train undergraduate and graduate students and a postdoctoral researcher. The project aims to broaden participation in ocean sciences by developing a new hands-on laboratory course at the college level. The lead scientist will collaborate with teachers and develop ocean chemistry learning modules for use in standard high school courses.

The principal investigator and his team will utilize a custom laboratory model system and in-situ metagenomics to reveal which organisms colonize marine particles and how, which successional metabolic patterns emerge, and the consequences that these microscale properties have for the water column. Specifically, the competitive advantage that bacteria with chemotaxis, motility, and denitrification abilities have for colonizing marine particles will be explored through a combination of precision microfluidic experiments in the laboratory and bioinformatics analysis of samples collected from the eastern tropical Pacific Ocean. The work will further investigate the effects that pore networks have for promoting particle colonization by changing the physical flows and resolving the dynamic chemical landscape within a particle. Results from these experiments will be used to translate the mechanisms of life at the microscale to global ocean biogeochemistry.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.