Current Notable Positions
- Co-Editor-In-Chief of the not-for-profit international scientific open access journal Biogeosciences (Copernicus Publishing)
- Member of the H.C. Urey Award Committee (European Association of Geochemistry)
- Director of UCLA’s Marine Center at the Institute for the Environment and Sustainability
- Member of the Board of Directors of the Southern California Marine Institute
My Research Background and Interests
I find it sometimes hard to define my research area, because of my broad background and interests. I received my diploma in biological oceanography, physical oceanography, and zoology from the University of Kiel in Germany. In my diploma thesis I studied the community structure and energy budget of deep-sea scavengers, including fish, crabs, and amphipods.
It was not really until my PhD thesis that I developed great interest in marine microbiology and biogeochemical processes. At the Max Planck Institute for Marine Microbiology I studied the anaerobic oxidation of methane (AOM) in sediments and graduated with a PhD in Biogeochemistry. It was an exciting time to do research on AOM (and still is), because my advisor Antje Boetius had just discovered the organisms that are responsible for this process in the year I started my PhD.
Methane has since then been one of my pet subjects and I am very broadly interested in all metabolic processes that are involved in the production and consumption of methane. Methane is an interesting molecule – it is the end product of organic matter degradation, the simplest organic compound, an energy source for microbes and humans, and a strong greenhouse gas.
Since a couple of years my new research has focused on marine oxygen minimum zones and coastal hypoxia. Scientists agree that the oceans are losing oxygen due to warming and eutrophication, but we are still far from understanding how these low oxygen environments function. My research aims at deciphering biogeochemical cycles in oxygen minimum zones (including nitrogen, iron and sulfur cycling) and to provide a baseline for predictions of future developments under climate change.
Aside from these two major research areas my group has studied a broad range of marine geomicrobiological processes, including petroleum degradation, plastic alteration, biogeochemial processes at whale falls, deep-biosphere metabolisms, and microbial precipitation and alteration of carbonates.
In general one could say that my research aims at answering the following ecological core questions:
– Which organisms live in an ecosystem and what are they doing?
– What are the physical and geochemical characteristics that makes an environment attractive for certain organisms?
– What impact do organisms have on their ecosystem?
– How could changes in the ecosystem affect its organisms?
In my lab we use a couple of standard methods to explore marine ecosystems and geomicrobiological processes:
(1) quantification of microbial turnover rates (e.g. methanogenesis, methane oxidation, sulfate reduction, nitrogen fixation) with radiotracer incubations and in-vitro experiments
(2) geochemical porewater analyses (titration, ion chromatography, spectrophotometry)
(3) high-resolution measurements of geochemical profiles with micro-electrodes
(4) gas chromatography
(5) molecular methods (CARD-FISH and epifluorescence microscopy)
We collaborate with many other labs to expand our methodology, depending on the research questions we ask.
I consider myself lucky that my research requires field work, which has taken me around the world on many research vessels. I spend over two years on the ocean, been in submersibles to dive into the deep sea and saw environments with my own eyes that few have seen before. The ocean is a fascinating place and there is still so much to discover.
UCLA Marine Center
Since May 2016 I am the Director of the Marine Center at UCLA’s Institute of the Environment and Sustainability (IoES). I made it my goal to bring together marine sciences and facilitate exchange between different marine disciplines on campus. The Marine Center has dedicated its research to understand the breadth of human impacts on the oceans.