David Fischer

Scientific papers
Niemann, H., Fischer, D., Graffe, D., Knittel, K., Montiel, A., Heilmayer, O., Nöthen, K., Pape, T., Kasten, S., Bohrmann, G., Boetius, A. and Gutt, J. (2009). Biogeochemistry of a low-activity cold seep in the Larsen B area, western Weddell Sea, Antarctica. Biogeosciences 6, 2383-2395.

Pape T., Feseker T., Kasten S., Fischer D., Bohrmann G. (2011) Distribution and abundance of gas hydrates in surface deposits of the Håkon Mosby Mud Volcano, SW Barents Sea. Geochemistry, Geophysics, Geosystems (G3). 12, Q09009. doi:10.1029/2011GC003575

Bogus, K. A., Zonneveld, K. A. F., Fischer, D., Kasten, S., Bohrmann, G., and Versteegh, G. J. M.: The effect of meter-scale lateral oxygen gradients at the sediment-water interface on selected organic matter based alteration, productivity and temperature proxies, Biogeosciences, 9, 1553-1570, doi:10.5194/bg-9-1553-2012, 2012.



Talks
Niemann, H., Fischer, D., Graffe, D., Knittel, K., Montiel, A., Heilmayer, O., Pfeifer, K., Pape, T., Kasten, S., Bohrmann, G., Boetius, A., Gutt, J. (2008) A low-activity cold seep in the Larsen B area, western Weddell Sea, Antarctica. Geophysical Research Abstracts, 10, EGU 2008, Vienna, Austria

Fischer, D. (2009, invited) Durch kalte Quellen (cold seeps) beeinflusste marine Environments – von der Antarktis bis in die Arabische See. Geographische Gesellschaft Bremen/Wittheit zu Bremen (in german), Bremen, Germany

Fischer, D., H. Sahling, K. Nöthen, G. Bohrmann, H. N. Schulz, M. Zabel and S. Kasten (2010) Biogeochemical and transport processes at cold seeps of the Makran accretionary prism. Annual MARUM retreat, Farge, Germany

Fischer, D., Sahling, H., Nöthen, K., Bohrmann, G., Schulz-Vogt ,H. N., Zabel, M. & Kasten, S. (2010) Biogeochemical and transport processes at cold seeps of the Makran accrteionary prism off Pakistan.
Conference on Gas in Marine Sediments, Listvyanka, Russia

Pop Ristova, P., Wenzhöfer, F., Zabel, M., Fischer, D., Kasten, S., Boetius, A. (2010) In situ biogeochemistry of methane, sulfur and oxygen in different chemosynthetic habitats at the giant pockmark - REGAB
Conference on Gas in Marine Sediments, Listvyanka, Russia



Posters
Fischer, D., Niemann, H., Montiel, A., Heilmayer, O., Pfeifer, K., Kasten, S., Bohrmann, G., Boetius, A. und Gutt, J. (2007) A low-activity cold seep in the Larsen B area, western Weddell Sea, Antarctica. Geologische Vereinigung, Conference 2007 Bremen

Fischer, D., Sahling, H., Bohrmann, G., Zabel, M. and Kasten S. (2009) Geochemical zonation and characteristics of cold seeps along the Makran accretionary wedge off Pakistan. EGU 2009, Vienna, Austria

• marine biogeochemistry
• cold seeps
• authigenic minerals
• gas hydrates

The formation of authigenic minerals at sites of hydrocarbon seepage (cold seeps) is in the focus of recent research. In this context mineralization represents a sink for the involved elements and hence carbonate formation (Aragonite, Dolomite, Mg-Calcite) and accordingly the removal of Carbon from the short C-cycle are in focus. However, the exact mechanisms of carbonate precipitation in cold seep environments are still subject to discussion. And yet less is known about the precipitation of other minerals, as e.g. barites or iron sulfides. This is where the present PhD-project steps in with a number of questions:
1. Which minerals of the aforementioned groups precipitate under which cold seep-conditions and why?
2. How do macro- and microfauna influence the mineral formation?
3. Do biomarkers remain in the record that hint on involved organisms (fauna, bacteria, archea)?
4. What is the potential stability of authigenic minerals over time?
5. And how large is their potential as tracers for past (palaeo-) cold seeps?
6. Do authigenic minerals store information about cold seep intensity and seeping fluid composition?