since Sept. 2008	Head of the Max Planck Research Group for Marine Geochemistry at the Carl von Ossietzky University (Oldenburg, Germany)
2003-2008	Assistant Professor Florida State University, Department of Oceanography, Tallahassee (USA)
2000-2003	Research Associate Alfred Wegener Institute for Polar and Marine Research, Bremerhaven (Germany)
1996-1999	Doctoral Fellow Center for Tropical Marine Ecology at the University of Bremen (Germany)
1989-1990	Employee, Environmental Protection Office (Ravensburg, Germany)

Academic Awards and Honors

since 2009	Courtesy Professor at Florida State University (FSU)
since 2007	Courtesy Professor at Florida Agricultural and Mechanical University (FAMU)
2001 - 2003	Research Fellow of the German Research Foundation (DFG) at the School of Oceanography (University of Washington)
2001	DIALOG IV fellow (Dissertations Initiative for the Advancement of Limnology and Oceanography)
2000	Wilhelmshaven-Award for Marine Research 2000
1990-1995	Scholarship of Studienstiftung des Deutschen Volkes