Award: OCE-1416665

Microbes are the most abundant organisms on the planet, and are responsible for much of the oxygen we breath as well as the health and productivity of the oceans. Global change is predicted to alter microbial composition, activity and function in the coastal ocean, through changes in environmental parameters, weather patterns, and ocean physics, among other factors. In this project, we examined the impacts of ocean acidification and temperature on microbes using a combination of field observations (coastal time series), mesocosm manipulations and work with model systems in the lab. Across studies, one of the main observations was that even small temperature changes (~ 3C) alter the community composition of microbes , biogeochemical rates and (meta)transcriptomes. Similarly, our field observations in our nearshore time series the Pivers Island Coastal Observatory (PICO; Beaufort, NC) and on research cruises from the coast out to open ocean conditions have found that bacteria, phytoplankton, fungi and labyrinthulomycetes communities changes are all associated with temperature, suggesting temperature is a critical environmental factor for diverse microbial groups. Notably, increasing ocean acidity (-0.3 pH units) did not dramatically alter microbial communities or their metatranscriptomes, suggesting that short term changes in acidity do not exert the same strong influence as temperature in our system. One of the major goals of our research was to compare microbial sensitivity to environmental changes between our nearshore study site (PICO), which has large annual and even daily fluctuations in environmental parameters and a site offshore at the continental shelf break which is a more constant environment. Our experiments suggest that offshore microbial communities may be more sensitive to warming, even when the temperature does not exceed the annual temperature range at that site. As much of the microbial global climate research occurs on coastal microbes, we should consider that these studies may underestimate the responses of the smallest residents of the oceans. In addition to scientific products including meeting presentations, publications and seminars, this project supported and trained numerous graduate students, undergraduate students, postdoctoral associates and technicians. Both labs presented interactive ocean acidification and marine microbiology outreach to several hundred members of the public annually at the Duke Marine Lab Open House. Additionally, a number of the graduate students on this project worked with local school teachers to co-develop classroom teaching modules focused on marine microbiology, through the graduate-student led Scientific Research Education Network. Several team members including Hunt have led local Girl Scout chapters to provide science outreach and mentoring to young women. Last Modified: 05/12/2020 Submitted by: Zackary I Johnson