Congratulations to Max Packebusch on receiving the 2026 NSF Graduate Research Fellowship Program (GRFP) award in Geosciences/Geochemistry. The fellowship will provide three years of support for Max during his PhD studies.

Cheers to you, Max!

Big congratulations to Emily Klonicki-Ference, who defended her PhD thesis successfully on July 14, 2025. The topic of Emily’s thesis is ‘Microbial Regulation of Methane and Redox Dynamics in the Water Column: From a Proterozoic Ocean Analog to Modern Marine Seeps’.

Well done, Dr. Emily Klonicki-Ference! 🙂

Our group recently received a couple of awards and other good reasons to celebrate:

PhD student Emily Klonicki received the Outstanding Student Presentation Award for her oral presentation at AGU 2024.

Master student George Vetushko received two awards to conduct research in salt marshes: (1) The Mildred E. Mathias Graduate Student Research Grant from the California Institute for Biodiversity, and (2) the Bloom-Hays Ecological Research Grant from Sea & Sage Audubon.

Our undergraduate students Yuzona Kodo and Sofie Sundberg received the EPSS Undergraduate Research Award made possible by the Deane Oberste-Lehn Scholarship to support their undergraduate research.

I myself was honored with a Corresponding Membership at the Göttingen Academy of Sciences, Germany’s oldest scientific academy, established in 1751 (more here), and a nomination for the 2025 Faculty Excellence in Graduate Student Mentoring Award.

Cheers to everyone! 🙂

This winter, Maxwell (Max) Packebush joined our group to complete his PhD in the EPSS Geochemistry Program.

Max earned his BS in molecular biology and microbiology from the University of Wyoming. While working under Dr. Thomas Boothby at UWyo, he published research on intrinsically disordered proteins from an extremotolerant organism in Scientific Reports. Following graduation, he completed a year-long post-baccalaureate position at NASA Ames Research Center, where he worked under the mentorship of Dr. Mark Ditzler. During this time, his research focused on investigating the role of amyloid formation in the early evolution of enzymes.

For his graduate studies in our group, Max will be involved in research on extremophiles.

Welcome to UCLA, Max!

Big congratulations to Jiarui Liu, who defended his PhD thesis successfully on November 8th, 2024. The topic of Jiarui’s thesis is ‘The Biogeochemistry of Methane Cycling and its Clumped Isotope Effects’.

After his graduation, Jiarui will start his Postdoctoral Fellowship in Marine Microbial Ecology, awarded by the Simons Foundation, in collaboration with UC Santa Barbara (Dr. Dave Valentine).

Well done, Dr. Jiarui Liu! 🙂

This fall, Rhegan Thomason joins our group to complete her PhD in the EPSS Geochemistry Program.

Rhegan received her Bachelor of Science in Biological Sciences from the University of Texas at El Paso. Her research interests focus on marine microbial ecosystems, biogeochemical cycles, and how environmental changes impact marine life. Recently, she worked as an NSF C-CoMP Bridge-to-PhD Fellow at Woods Hole Oceanographic Institute, using ecosystem models to study how physical and biogeochemical factors influence heterotrophic marine bacteria. She has also researched the effects of ocean acidification and eutrophication on shellfish in Massachusetts estuaries.

For her graduate studies in our group, Rhegan will be involved in reasearch on the marine microbial methane cycle.

Welcome to UCLA, Rhegan!

In May and June of 2024, my research group embarked on an NSF-funded expedition to explore methane seeps in the Aleutian Trench off Alaska. Our mission was to investigate the role of methane-derived carbon in deep-sea ecosystems as part of the ongoing ‘Methanosphere’ project. This expedition, the second of the project, was led by Dr. Lisa Levin from Scripps Institution of Oceanography, with Co-PIs Dr. Victoria Orphan (Caltech), Dr. Shana Goffredi (Occidental College), and myself.

We targeted methane seeps located at depths between 2000 and 5000 meters off the Aleutian Islands, and thanks to the newly enhanced deep-dive capacity of the Alvin submersible, which now reaches 6500 meters (up from its previous limit of 4500 meters), we were able to push the boundaries of exploration. Our team had the privilege of being the first scientific group to utilize Alvin’s expanded capabilities for research, allowing us to delve deeper into these remote and poorly understood environments.

During our 2024 expedition, we explored three key sites: EDGE, SHUMAGIN, and SANAK. The EDGE and SHUMAGIN sites hold a special place in deep-sea exploration, as they were first discovered 30 years ago by Dr. Erwin Suess’s group from GEOMAR in Germany. These were the deepest locations we visited, with water depths ranging from 4700 to 5000 meters.

A particularly meaningful moment for our team was revisiting the former sampling sites of Dr. Suess’s group. In honor of his incredible contributions to marine science, we deployed a memorial rock for Dr. Suess, who sadly passed away on September 28, 2023. You can read a special article about the memorial rock deployment and his research legacy on the GEOMAR website.

In an unexpected twist, we found no massive outcropping carbonate structures at these deep sites, which suggests that carbonates may dissolve back into the ocean water below the carbonate compensation depth—a discovery that could add new insights into the carbon cycle in deep-sea environments.

The SANAK site, our shallowest at approximately 2000 meters, was a recent discovery by NOAA and stands out for its extensive carbonate structures and thriving tubeworm fields. As we began sampling, we were met with an unexpected phenomenon—a major marine snowstorm. This flurry of organic particles falling from the surface added a layer of complexity to our study, sparking questions about the seasonality of carbon supply to this seep ecosystem. The presence of such a substantial carbon flux during our visit could have important implications for understanding the temporal dynamics of food sources for deep-sea communities like the one at SANAK.

Everyone on board was filled with excitement and anticipation as we studied these unique deep-sea habitats. We are incredibly grateful for the unwavering support and expertise provided by the Alvin and Atlantis teams, without whom this research would not have been possible. Their dedication played a crucial role in making this expedition a success, and we deeply appreciate their contributions to advancing our understanding of these remarkable environments.

Departing from Kodiak Island aboard the RV Atlantis, with the pilot boat alongside on the left, we set off on our next scientific adventure.

Submersible Alvin is launched for a dive to the deep-sea methane seeps.

Inside Alvin during a dive. Happy divers 🙂

Methane seep communities (symbiotic frenulate worms and clams) at the SHUMAGIN seep at about 4880 m.

Marine snowstorm over a tubeworm field at the SANAK methane seep (2000 m).

Orange sulfur bacteria mat collected with an Alvin pushcore at the SANAK seep.

Subsampling of a sediment push core collected by Alvin.

Authigenic carbonate rock from the SANEK seep, formed through intense microbial activity associated with the anaerobic oxidation of methane (AOM) in the sediment. These rocks serve as habitats for a variety of organisms, both within and on the surface, highlighting the intricate relationship between microbial processes and deep-sea ecosystems.

Sawing of methane carbonate rocks for incubations and analyses.

Alkalinity titration of porewater collected from sediment cores.

Collection of water samples to study methane and microbial methane oxidation in the water column.

Foam cup before/after diving with Alvin: Crushed by the pressure at 2000 m.

UCLA Team with student trainee from the Alaska Native Science & Engineering Program (from left to right): Stefani Martinez (ANSEP), George Vetushko, Jiarui Liu, Dr. Kira Homola, Emily Klonicki, Dr. Tina Treude.

PIs with the Suess Memorial Rock (from left to right): Dr. Shana Goffredi, Dr. Victoria Orphan, Dr. Tina Treude, Dr. Lisa Levin (Chief Scientist).

Congrats to my master student George Vetushko, who received the NSF Graduate Research Fellowship, and my graduate student Jiarui Liu, who received the UCLA Dissertation Year Fellowship. You both Rock!

Big congratulations to my two graduate students DJ and De’Marcus, who both defended their thesis on April 29 and graduated end of spring. Both worked on biogeochemical processes related to the oxygen minimum zone in the Santa Barbara Basin.

Well done Dr. Yousavich and Dr. Robinson 🙂

This Fall, George Vetushko, (re)joins our group as graduate student to complete a master in EPSS. George received his Bachelor of Science in Astrobiology at UCLA. While at UCLA as an undergraduate student, George led an undergraduate team of students in modeling Southern Californian fugacious coastal lagoon environments from aerial data and in-field sampling supervised by Dr. Dave Jacobs (EEB). He further completed a research-oriented course in radar astronomy alongside Dr. Jean-Luc Margot (EPSS) parsing through potential technosignatures from SETI data and classifying patterns of radiointerference. In our group, George completed a senior undergraduate thesis on the coupling of anaerobic oxidation of methane to nitrate reduction in a Southern California wetland. George further supported our group as undergraduate researcher in the lab and onboard the RV Atlantis during our 2023 expedition to the Santa Barbara Basin.

For his graduate studies in our group, George plans to continue his work on climate-change related trends in the coupling of anaerobic oxidation of methane to nitrate reduction in coastal wetland environments.