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.
End of June 2023, our group set ‘sail’ to participate in two back-to-back marine research expeditions onboard the research vessel Atlantis (AT50_11 and _12), which hosts the famous deep-sea submersible Alvin. The total length of the two expeditions, which were supported by the National Science Foundation and organized by the Woods Hole Oceanographic Institution, was over 5 weeks and took us to two different types of marine environments off the coast of southern California.
The first expedition (AT50_11) focused on microbial processes in the oxygen minimum zone of the Santa Barbara Basin. High productivity of plankton in the surface water and weak ventilation of the deep basin water triggers a strong decline of oxygen when bacteria feed on decaying planktonic biomass. The degradation of the organic material at the seafloor initiates a complex set of microbial and chemical processes, including the development of massive sulfur bacteria mats, which feed on hydrogen sulfide produced in the sediment. While most of these processes are natural, we are also interested to understand potential intensification and alteration of the processes related to human impacts such as climate change. For our research, we descended to the seafloor (maximum depth around 590 m) with the submersible Alvin for the deployment of chambers to measure fluxes of chemicals (such as oxygen, nitrate, sulfide) into and out of the sediment. Further analytical support was provided by the cute autonomous underwater vehicle (AUV) Sentry, which completed several pre-programmed dives through the Santa Barbara Basin without a pilot to measure oxygen distribution and to monitor seafloor coverage of the sulfur bacteria mats. This NSF-funded expedition was a collaboration with the UC Santa Barbara (Dr. David Valentine), the Alfred Wegener Institute in Germany (Dr. Felix Janssen), and the Mt. San Antonio College (Dr. Tania Anders)
The second expedition (AT50_12) aimed at cold seeps that release fossil methane from the seafloor. Cold seeps are found at many locations off the coast of southern California (Malibu, Santa Monica, Redondo Beach, Palos Verdes, San Pedro, Del Mar) and seepage is often facilitated through migration of methane along tectonic fault systems. The methane serves as an energy and carbon source for many organisms and creates special cold seep communities. The seep ecosystem usually starts with microbes, who feed on the methane and provide biomass for other organisms higher up in the food chain. The overall aim of the project was to understand the connectivity between methane and organisms and the importance of cold seeps for the overall health of the deep-sea ecosystem. On our dives to the up to 1000 m deep methane seeps, we collected seep rocks (carbonates made from methane-derived carbon) and sediments to study methane-eating microbes and animals associated with this ecosystem. This NSF-funded expedition was a collaboration with the Scripps Institute of Oceanography (Dr. Lisa Levin), the Occidental College (Dr. Shana Goffredi) and Caltech (Dr. Victoria Orphan).
Diving with a deep-sea submersible such as Alvin is a dream come true for many marine scientists. It is not unlike boarding a spaceship – only few people in the world get a chance to experience it. Before boarding the submersible, scientists receive a safety training and must obey several safety rules, such as only wearing flame-resistant clothes and leaving any non-tested electronics such as cellphones behind. All Alvin pilots are Navy-trained and the solid titan sphere that holds the humans is approved for dives up to 6,500 m (21,325 feet). Once on board (usually two scientists and one pilot), everyone gets busy quickly to make sure samples requested are taken and documented with video cameras. The usual 6-8 hours in the sub fly by quickly. For the hungry ones, lunch boxes with sandwiches and chocolate are provided – so is a ‘toilet’ in the form of a plastic bottle. If people get asked what their most memorable moment in the submersible was, many mention the bioluminescence (glow) of organisms in the darkness of the deep sea. Once returned to the surface, those who experienced their first Alvin dive are welcomed back by the science crew with a bucket of ice-cold water, a joyful ceremony known as the ‘Alvin baptism’.
Next year, in late spring 2024, our group will get closer to Alvin’s dive limit when we will explore methane seeps off Kodiak Island (Alaska) at depths up to 5,500 m. Data gained during this future expedition will be compared to data from the shallower southern Californian seeps to study shifts in the relevance of methane for the ecosystems relative to water depth.
Watch also the ‘Women of the Deep’ video produced by Lisa Levin’s group on YouTube.
This fall, Dr. Kira Homola joins our group for two years to work with us on our NSF-funded methane seep project. Kira received the prestigious NSF postdoctoral research fellowship. In her project, she will assess how much of the carbon captured when rocks form at deep ocean methane seeps is released back into the water column over time due to biomediated corrosion.
Born in Hawaii, Kira grew up in the Salish Sea of Washington state where she fell in love with the ocean and natural world. In 2013, she completed two bachelors of science degrees from the University of Washington (UW), one in mechanical engineering and one in oceanography with a minor in climate science. During her three years at UW, she was able to spend four months at sea on oceanographic expeditions. She continued her studies at the University of Rhode Island with the lab groups of Dr. Art Spivack and Dr. Rebecca Robinson. In 2020, she completed her PhD in Oceanography on the fate of atmospheric carbon in ancient oceans and the temperature and pressure limits of microbial life using techniques including porewater geochemistry and thermodynamic modeling.
This summer our group conducted three different fieldwork activities. We had a lot of fun in the outdoors and collected tons of samples and data that will keep us busy for the next months.
Fieldwork Activity 1: Santa Barbara Basin with the R/V Shearwater
End of July, our group –in collaboration with the group of Dr. David Valentine (UCSB)– went out with the NOAA-operated vessel R/V Shearwater to the Santa Barbara Basin. We deployed a CTD and our miniaturized multicorer to collect data and samples from one of our deepest low-oxygen stations. The main focus of this NSF-funded project is to study the seasonality of sulfur bacteria mats in the Santa Barbara Basin and the underlying biogeochemical processes.
Fieldwork Activity 2: Carpinteria Salt Marsh Reserve
In early August our group visited the Carpinteria Salt Marsh Reserve, which is a UC reserve operated by UCSB, to study methane emission dynamics and collect sediment with a special hand corer. This NSF-funded project studies cryptic methane cycling in the salt marsh sediments, which is the relation between methanogenesis and anaerobic oxidation of methane.
Fieldwork Activity 3: Green Lake, Upstate New York
As part of the NASA ICAR project, and in collaboration with the group of Timothy Lyons (UCR), our group studied microbial processes in the water column and sediment of Green Lake in Upstate New York mid August. The lake is meromictic with a sharp chemocline around 18-20 m water depth. The conditions in the lake are reminiscent of biogeochemical processes in early-Earth oceans and we are interested in understanding the interplay between different microbial processes (mainly sulfate reduction, methanogenesis, and methane oxidation) and geochemistry. Samples were collected from row boats and a Pontoon boat. We had great support and collaborations with the Green Lake Educational Center, Dr. Christopher Junium from Syracuse University, and Dr. Michael McCormick from Hamilton College.
Congrats to De’Marcus Robinson on receiving the 2023 Sea Grant Knauss Fellowship! The Knauss Fellowship provides a unique educational and professional experience to graduate students who have an interest in ocean, coastal and Great Lakes resources and in the national policy decisions affecting those resources.
De’Marcus’s will join 86 finalists to be placed in federal government offices in Washington, D.C. beginning February 2023.
This Fall, Emily Klonicki is joining our group as a new graduate student in the Earth, Planetary, and Space Sciences Department.
Emily joins us from NASA’s Jet Propulsion Laboratory, where she was a planetary Protection and Systems engineer and participated in different missions including the Planetary Protection for Europa Clipper and Europa Lander and the Science Definition Team for the Europa Lander mission concept.
Emily will be working in our NSF Collaborative Research Grant: “Redefining the footprint of deep ocean methane seepage for benthic ecosystems“ and in the NASA project “Alternative Earths – How to Build and Sustain a Detectable Biosphere“. You can learn more about Emily on her personal page.
Check out our new manuscript on “Rapid sulfur cycling in sediments from the Peruvian oxygen minimum zone featuring simultaneous sulfate reduction and sulfide oxidation” by Tina Treude, Leila J. Hamdan, Sydnie Lemieux, Andrew W. Dale, and Stefan Sommer:
Check out our new manuscript entitled “Deciphering cryptic methane cycling: Coupling of methylotrophic methanogenesis and anaerobic oxidation of methane in hypersaline coastal wetland sediment” by Sebastian Krause & Tina Treude that was just accepted in Geochimica et Cosmochimica Acta: