The oceans have played and still have a dominant role in the evolution of life, biogeochemical cycling, and climate. Marine organisms mediate many processes in the ocean, including carbon and nutrient cycling. Sediments deposited on the ocean floor form the most complete and accurate archive to study past climate change, under various natural states. The study of the past and present oceans and biota is thus of prime importance for elucidating response to rapid perturbations. The Biomarine Sciences (BMS) group of the University of Utrecht studies the oceans in all aspects, particularly focusing on present and past marginal marine ecosystems.
Currently, we are looking to fill two PhD positions within the Biomarine Sciences group.
2 PhD researchers: Biomarine Sciences (2 * 1.0 fte)
Project description
From Protist to Proxy: Dinoflagellates as signal carriers for climate and carbon cycling during past and present extreme climate transitions
Along with climate warming, anthropogenic CO2 is currently causing a significant increase in ocean acidity. The effects of ocean acidification on life and the marine carbon cycle are still poorly understood. Past analogues of rapid carbon injection and extreme climate change can aid in the identification of vulnerable groups and in improving projections of the consequences of this acidification. Unfortunately, despite recent progress, changes in surface ocean pH through the geological past are not well constrained due to the lack of well-calibrated proxies for the limited pH range involved.
Dinoflagellates are protists that comprise a vital component of the primary production in the oceans. Approximately 15% of the dinoflagellates exhibit a complex life cycle that includes the formation of an organic cyst. These cysts preserve well in sediments (their fossil record goes back ~230 million years), and have been widely applied in biostratigraphic and paleoenvironmental studies. Ongoing culturing experiments have indicated that differential incorporation of the stable 12C and 13C isotopes into dinoflagellates and their cysts is related to the CO2 concentration and pH, of seawater. Building on the culturing experiments, this project aims to develop and apply this relation as a new proxy for surface ocean carbon speciation.
PhD Project 1 (projected start: spring 2011): Calibrating a new proxy for marine carbon cycling using subrecent and glacial/interglacial organic dinoflagellate cyst geochemistry.
This project is designed to quantify the relation between ocean carbonate chemistry and dinocyst stable isotope geochemistry using late glacial and Holocene sedimentary sequences. The study will involve organic geochemical analyses, particularly d13C measurements, of several dinocyst species across the rise in atmospheric pCO2 of the last 150 years. Sediments cores with at least decadally resolved age models from several oceans will be used. Moreover, high-resolution records will be generated across the last deglaciation. Also dinoflagellate (cysts) from sediment traps will be analyzed. Results will be integrated in multi-proxy records to reliably reconstruct past paleo-seawater pCO2.
PhD Project 2 (projected start: summer 2011): Reconstructing marine carbon cycling during past Extreme Climate Transitions.
Single dinocyst species stable carbon isotope records across past episodes of rapid and massive carbon injection, such as the Paleocene-Eocene thermal maximum (~56 million years ago; Ma), Eocene Thermal Maximum 2 (~54 Ma) and the Middle Eocene Climatic Optimum (~40 Ma) will be generated. Moreover, episodes of CO2 drawdown, such as the Eocene-Oligocene transition (~34 Ma) will be subject of study. This work will lead to documentation of paleo-seawater pCO2 across these critical extreme climate transitions.
The total project also involves one technician and is a collaborative project of Biology and Earth Sciences at Utrecht University, The Netherlands, and the Alfred Wegener Institute in Bremerhaven, Germany. The European Research Council (ERC) under the European Community’s Seventh Framework Program funds the project, by a grant awarded to Dr. Appy Sluijs. The primary place of work is Utrecht.
Qualifications
We seek highly motivated candidates (MSc) with excellent communication skills with experience in Biogeology or Paleoceanography, particularly in organic geochemical, stable isotope, paleontological and ocean acidification research on the boundary between Biology, Earth Sciences and Paleoceanography. Candidates are expected to communicate easily in English, both verbally and in writing.
Terms of employment
The successful candidates will be offered a full-time PhD position for a period of four years. Conditions are based on the Collective Labour Agreement of the Dutch Universities. Salary starts with € 2,042.- gross per month in the first year and increases to € 2,612 gross in the fourth year op appointment. The salary is supplemented with a holiday bonus of 8% and an end-of-year bonus of 8,3% per year. In addition we offer: a pension scheme, a partially paid parental leave, flexible employment conditions. The research group will provide the candidate with necessary support on all aspects of the project.
More information on employment conditions is available on the website of Utrecht University: www.uu.nl/vacancies.
Further details
Additional information about the vacancy can be obtained from Dr. Appy Sluijs (A.Sluijs@uu.nl). As part of the selection procedure, the candidate is expected to give an outline of his/her research interests in a written report. A shortlist of candidates will be interviewed. You may also wish to visit the websites of:
Department of Biology
http://www.uu.nl/faculty/science/EN/organisation/depts/biology/Pages/default.aspx
Institute of Environmental Biology
http://www.uu.nl/faculty/science/EN/research/researchinstitutes/IOEB/Pages/default.aspx
Biomarine Sciences group
http://www.uu.nl/faculty/science/EN/organisation/depts/biology/research/chairs/BiomarineSciences/Pages/default.aspx
How to apply
Please include with your application, a letter of motivation, curriculum vitae and contact details of at least two references. Send your application before the 7th of February, 2011 to email: Science.PenO@uu.nl
Please mention vacancy number 66101 and if you are applying to project 1, 2 or both, and where you originally saw this advertisement.
