Award: OPP-1644155

The ice sheet over Antarctica, which comprises ninety percent of Earth's ice, influences global climate and buffers the effects of global warming. However, Antarctic environments and the organisms that live in them appear to be particularly sensitive to climatic changes. While most ecology studies in Antarctica focus on large animals and algae that live in coastal areas and the surrounding seas, relatively little is known about the microbes in those environments. Microbial life forms the base of the food web and drives globally important processes, and viruses are drivers of microbial diversity, productivity rates, and evolution. Hundreds of lakes along the Antarctic coastal fringe contain seawater trapped thousands of years ago and harbor active microbial communities. Isolation has led to distinct environmental characteristics that support different organisms within individual lakes. These "natural laboratories" allow the examination of microbial processes and interactions in Antarctica. This project investigated the viral communities and their interactions with their hosts in three lakes in the Vestfold Hills in Antarctica, each one deemed representative of many other lakes along the Antarctic coastal fringe. The study's results confirmed that viruses of eukaryotic microbes, such as microscopic algae, are abundant and diverse in those lakes. Microscopy algae get their energy primarily from photosynthesis using sunlight. In Antarctica, these algae are more abundant during the light summer months than in the dark months when alternative sources of energy are required. In contrast, the eukaryotic virus particles in the lakes, which depend on those algae as hosts, did not show wide inter-annual abundance fluctuations between the light and dark months. This result suggests that viral particles released into the water from infected microalgae persist in the environment for long periods and may re-infect new host populations during the summer months. The project provided scientific training in aquatic virology and computational biology for one full-time (Dr. Silvia Cretoiu) and one part-time (Dr. Anne Booker) female postdoctoral researcher. The project supported Dr. Cretoiu's participation at the 2018 Joint Genome Institute Annual Meeting and the 2020 Ocean Sciences Meeting, where she presented a poster entitled "Algae and associated viruses in a marine-derived Antarctic lake." Additionally, this project supported and trained summer intern Emily Haggett (a first-generation community college student). She was selected among a pool of Bigelow Laboratory interns to give a talk about her project at the 2019 Aquatic Sciences Meeting. Attendance at international conferences provides excellent career opportunities, especially for early-career scientists, to network and learn about the most recent and innovative worldwide advances in research. Dr. Martinez Martinez, the original lead scientist in this project, collaborated with local artist Justin Levesque and discussed the discoveries from this work with non-scientific audiences through outreach events at Bigelow Laboratory for Ocean Sciences. Last Modified: 12/11/2022 Submitted by: Benjamin S Twining