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Bryan Niederbockstruck

Institution: University of Bremen
Office: MARUM C7
Phone: +49 421 218 - 65674
E-mail: bnie­der­bock­struck@marum.de
Other webpage(s): Bryan's MARUM web page

 

Bryan Niederbockstruck

PhD Project

Calcareous nannoplankton: Tiny size but heavy impact?

In the geological past, the climate has shown different faces with changes in temperature and atmospheric CO2-concentration. As a result, the Earth faced extreme glaciations but also ice-free conditions even at high latitudes around the poles. One of these hothouse worlds occurred during the early Eocene, when ocean’s deep-sea temperatures are assumed to be 12°C higher and the atmospheric CO2-concentration exceeded 1000 ppmv. As a link between the deep sea and the atmosphere, the upper ocean plays a crucial role when it comes to the carbon exchange.  Within the surface waters, coccolithophores are the most calcifying organism among all the phytoplankton. These single-celled algae are about one thousand times smaller than a millimeter. While changes of climate conditions affect the productivity of the coccolithophores, they can in turn also affect the climate. Their ability of carbon fixation via photosynthesis and the production of calcite plates influences the air-sea exchange of CO2, thus making them a part of shaping Earth’s climate. While the photosynthesis and the later sinking of their bodies into the deep ocean removes CO2, the production of calcite plates releases CO2 into the atmosphere, making it complex to understand the feedback mechanism to climate change.

Within my PhD project I am studying the response of coccolithophores under changing climate of the early Eocene. Therefore, I am investigating the assemblages during, prior and after high CO2-concentrations to understand how sensitive these organisms react to different conditions. I will also evaluate the potential of the coccolithophores as a net sink of CO2 by calculating the ratio of the particulate inorganic carbon and the particulate organic carbon in order to see if they amplify or oppose climate change. The material for this study is provided by sediment cores of IODP Expedition 378. The sediment cores were drilled on the southern Campbell Plateau off New Zealand. Multiple-drilling holes contain one of the most continuous record of the Paleogene and provides a unique and detailed archive of the Eocene’s climate in a high-latitude area.

Thesis Committee

Prof. Dr. Heiko Pälike MARUM - Center for Marine Environmental Sciences, University of Bremen
Dr. Ursula Röhl MARUM - Center for Marine Environmental Sciences, University of Bremen
Dr. Torsten Bickert MARUM - Center for Marine Environmental Sciences, University of Bremen
Dr. Heather L. Jones MARUM - Center for Marine Environmental Sciences, University of Bremen