Award: ICER-2033934

Microbes serve as the key drivers of ecology and biogeochemical cycling in the ocean, providing essential ecosystem services, including primary production (photosynthesis) and organic matter turnover, that sustains all marine organisms. This project used a range of experimental and analytical techniques to examine factors structuring microbial communities and ecosystem variables.  Using data from our long-term time series at a coastal site at Beaufort Inlet, North Carolina, we observed annual cycles, long term trends in specific environmental variables and quantified how long environmental factors took to return to baseline following hurricanes Florence (2018) and Dorian (2019), which ranged up to ~50 days. Examining the impact of hurricanes on marine biomes is important because hurricanes are multi-factor disturbances that introduce both foreign freshwater and terrestrial microbes into a stable system while altering salinity, nutrients, and organic matter in the coastal ocean. We combined this field work with experimental manipulations of bacterial concentration (encounter rate) and increased organic matter from a diatom (single-celled algae) that blooms following hurricanes; interestingly, the treatments where we manipulated encounter rate and reduced competition (diluting microbes in filtered water from the same location) resulted in more widespread changes in the microbial community.  We also used a number of modeling approaches to better delineate water parcels that peel off from the Gulf Stream (eddies) and identified their boundaries using differences in the microbiome, examine spatial patterns across the coastal ocean and transition between observational and experimental studies.  By integrating multiple aspects of microbiome research, this work deepens current understanding of the coastal ocean microbiome system and its functionality. This project also developed new testable hypothesis to guide future research, specifically into the importance of terrestrial organic matter deposition into the coastal ocean during large storm events as well as transferable modeling approaches that can be applied broadly to other microbiology research topics outside of environmental science.

Broader impacts of the work include advanced training for undergraduate, graduate, and postdoctoral students, as well as translating research results into products for K-12 students and the public. This project supported the dissertations of two PhD students as well as the training of many undergraduate independent research projects.  We disseminated results to the broader public by working with local scouting troops to engage in hands-on science experiments (extraction of DNA) as well as engaging the broader public in demonstrations at lab “open house” events where we communicated our science efforts to several hundred local residents at a time.  As these events occurred in a rural county far from major research institutions (Duke Marine Laboratory), they reach communities that are have less access to university-based educational resources.

Last Modified: 12/03/2025
Modified by: Dana E Hunt