Project: Unraveling the Ecological and Evolutionary Drivers of Marine Giant Virus Community Dynamics

NSF Award Abstract:
Viruses are key players in modulating marine biogeochemical processes and populations of numerous microorganisms. Nucleocytoplasmic Large DNA Viruses (NCLDVs), commonly known as 'giant viruses', have garnered increased attention given their remarkable diversity and functions in the ocean. NCLDVs infect microbial eukaryotes (protists) with diverse life-strategies, highlighting their multifaceted role within the marine ecosystem. Despite significant advances in cataloging NCLDV diversity, the ecological drivers and evolutionary mechanisms shaping their community dynamics remain poorly understood. This study is elucidating the ecological and evolutionary determinants of marine NCLDV community structure through a comprehensive, year-long time-series analysis at a model coastal site, Quantuck Bay, NY. The investigators are assessing the importance of a range of environmental as well as intrinsic factors in shaping the diversity, function, and evolution of DCLDVs. To achieve this goal, samples are being collected over a year-long period to map out the genetic diversity and metabolic capacities of NCLDVs. In addition, using high-temporal resolution sampling over a three-month period, the project is evaluating how NCLDV ecological strategies map into the observed composition of marine microbes. Concurrently, the project evaluating how other environmental factors like nutrients and temperature shape the abundance and activity of the NCLDVs. Finally, the project is exploring the association of these giant viruses with diverse hosts. This research is providing critical insights into the ecological roles of NCLDVs in marine systems and their potential responses to environmental changes. This study is not only enhancing our understanding of giant virus ecology but also is providing valuable educational and training opportunities. The data and methods generated are being integrated into an undergraduate course on marine virus ecology and are being used to train undergraduate students in open science practices and standards. Furthermore, an effort is being made to increase diversity in marine science by recruiting students from underrepresented backgrounds and engaging with the public through annual outreach programs.

Giant viruses in the ocean are gaining scientific attention due to their enormous size and complex genomes encoding metabolic functions previously known to be only present in living organisms. These viruses, which infect a wide variety of marine organisms known as protists, play significant roles in shaping marine food webs and biogeochemical cycles. Despite their importance, very little is known about the factors that drive the ecology of these viral communities in the ocean. This research is exploring the ecological and evolutionary factors influencing the community dynamics of giant viruses in a coastal ecosystem in Quantuck Bay, New York. A detailed, year-long study is being conducted that combines advanced genomic and transcriptomic techniques to uncover the diversity and metabolic functions of these viruses along with their ecological strategies and host associations. Understanding the roles of giant viruses in marine ecosystems is crucial, especially as climate change continues to alter oceanic conditions. This research is providing crucial knowledge on how these viruses interact with their environment and hosts - information that is critical to predicting their impacts on marine food webs and biogeochemical cycles.

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.