Microscopic plants at the base of the marine food web known as phytoplankton take up CO2 from the

atmosphere through photosynthesis, contributing to the ocean's capacity to absorb and sequester

approximately a third of global CO2 emissions, providing a critical service regulating global climate. Nitrogen is

an essential nutrient for phytoplankton to grow and uptake CO2, but about half the ocean is deficient in

nitrogen. In those vast regions or 'ocean deserts', a diverse group of microbes can take nitrogen gas from the

atmosphere and convert it into nitrogen compounds that phytoplankton can use. Because of that, the overall

ability of the ocean to remove atmospheric CO2 depends on those nitrogen-fixing microbes. While scientists

have deciphered many environmental conditions that affect nitrogen-fixers, they still know very little about how

viruses influence their growth and ability to convert nitrogen. Through infection, viruses can kill microbes,

producing new virus particles and promoting the release of nutrients that become available as food to others.

In addition to causing death, infection alters the growth and behavior of the host microbes. In this project, the

research team will explore which and how viruses influence the process of nitrogen fixation in the Indian

Ocean, arguably the most understudied 'ocean desert'. Their ultimate goal is to better understand and allow

predictability of the ocean's productivity and ability to mitigate global climate change.