My research focus is on the microbial ecology of aquatic systems with emphases on viruses in the environment and their contributions to the ecology and evolution of eukaryotic and prokaryotic microorganisms and the ecology of human pathogenic vibrios in coastal waters.

Contact: grieg@hawaii.edu

Online CV

Department Profile

Nerissa earned her doctoral degree from the University of Technology Sydney. She has expertise in phytoplankton physiology and ecology. She is currently investigating grazing by protists on marine cyano- and heterotrophic bacteria using stable-isotope probing

Contact: fisherne@hawaii.edu

Department Profile

Dr. Schvarcz earned B.S. and M.S. degrees in Ecology and Evolutionary Biology from the University of Arizona, Tucson and a Ph.D. in Oceanography from the University of Hawaiʻi at Mānoa. His research focuses on the cultivation and characterization of marine eukaryotic phytoplankton and mixotrophs and the ecology and genomics of viruses that infect them. He currently works and resides in New Zealand, but remains affiliated with research on phytoplankton viruses here at UH.

Amanda earned a B.S. in Biological Sciences from the University of Pittsburgh. Her dissertation project is focused on marine viruses. She is trying to how differences in virion size influences the relative competitiveness of viruses in differing habitats.

Jess earned a B.S. degree in Marine Science from the University of South Carolina. Her current research project focuses on measuring the grazing rates of cultivated mixotrophic plankton on the most abundant bacteria in the ocean. 

 Julie joined the MarVEL team in Jan 2023 to work on genomic characterization of viruses that infect marine phytoplankton. She had prevously earned her doctoral degree from the Sorbonne University in France. Her dissertation research focused on the interactions between the marine picoalga Ostreococcus tauri and its giant viruses (genus Prasinovirus). 

Petra completed her doctoral degree in Oceanography at UH Manoa in 2025. Her graduate work focused on giant viruses of marine phytoplankton. Previously, Petra graduated from the University of Chicago with a B.Sc. in Geophysics.  As an undergraduate researcher she studied the impact of redox gradients on the structure of aquatic microbial communities (Marine Biological Laboratory, MA; Bermuda Institute of Ocean Sciences, Bermuda) and viral ecology in freshwater lakes (University of Chicago, IL). Petra joined the Steward lab as an NSF graduate research fellow in biological oceanography in the fall of 2018. SHe isnow a postdoctoral researcher at the University of Maryland's Horn Point Laboratory.

Adi completed his doctoral degree at UH Manoa in 2024. He previously completed his B.Sc. in Biochemistry and M.Sc in Marine Science at the University of the Philippines Manila and Diliman campus, respectively. Previously, he contributed to the development of an early predictive system for harmful algal blooms. He also applied -omics approaches to investigate the thermal resilience of corals and marine microbes in the Philippine archipelago. For his docoral work he investigated phytoplankton viruses. He is currenlty a post-doctoral researcher at Cornell University. You can visit his website for more information.