During this two year Postdoctoral Fellowship at the University of Hawaii, the PI will focus her research on understanding how microbes impact the distribution of iron and sulfur in the He'eia Fish Pond. Fish ponds have been an important part of the Hawaiian coastal system for hundreds of years, and this research will provide insights into microbial-mediated chemical cycles in Hawaiian estuaries. The results will be useful for Hawaiian coastal management and fisheries management. The PI will also serve as a mentor and role model for University of Hawaii undergraduates and organize a science outreach program for students at Kamehameha schools. The investment in this Postdoctoral Fellowship will advance the career of the PI who has strong background in microbial research, a field that is of increasing importance in oceanography.
Microbes account for more than 90% of biomass in the ocean, produce ~50% of the oxygen on Earth, and play crucial roles in mediating the biogeochemical cycling of elements such as carbon, nitrogen, oxygen, iron, phosphorus and sulfur. However we have a limited understanding of the specific biogeochemical processes that occur within the ocean, the kinetics of these processes, the taxonomy and physiology of the organisms responsible, the complex syntrophic interactions amongst community members, and the extent to which microbes influence the cycling of bioactive elements. Heeia Fishpond is a tidally-influenced, shallow Hawaiian coastal estuarine system where excessive primary productivity and respiration of phototrophic organisms generate striking diel variations in dissolved oxygen concentrations, and lead to substantial vertical migration of redox transition zones in both the sediment and water column. The PI will couple fine-scale redox measurements and bioenergetic modeling with molecular microbiology and direct measurements of metabolic rates to: (1) constrain the extent and distribution of chemotrophic energy metabolisms within the fishpond, (2) calculate the microbial impact on the speciation and distribution of iron and sulfur, and (3) characterize the diversity and distribution of active benthic microbial communities within the fishpond that regularly occur over the diel cycle.
