Title: Towards improved proxies calibration for corals Paleoclimatic reconstructions: Case study of the impact of seawater acidification on coral and boring microflora, Application.
The excellence Labex of the Institut Pierre-Simon Laplace (L-IPSL) offers a 1.5 years postdoctoral position
Context: Global climate change and ocean acidification are one of the most pressing issues in Earth Sciences today. This is supported by the growing scientific evidence that changes in ocean chemistry due to anthropogenic input are already occurring and will continue in the next decades to centuries at a rate that will depend on future CO2 emissions. Temperature and carbonate chemistry of the oceans are critical parameters that not only control chemical and physical processes, but also a wide range of biogeochemical processes that are important for the development and survival of marine biota such as corals, the main framebuilders of coral reef ecosystems. These organisms are highly threatened by global change and ocean acidification and represents major eco-systemic resources which support the survival of 1/15 of the world population. Recent studies suggest that net reef dissolution will occur by 2100 as corals will calcify less and as the microboring flora, one of the main agents of carbonate dissolution, will be stimulated.
Geochemical proxies preserved in the carbonate skeleton of marine calcifying organisms such as corals provide a unique tool to reconstruct changes in seawater environmental parameters since the beginning of the industrial era. Many parameters however might impair high-resolution time-series like vital effects and environmental stressors, which can bias geochemical signatures in corals and therewith paleo-reconstructions. It is thus essential to identify the biogeochemical processes involved in the incorporation of trace elements and isotopic signatures at the early stage of the aragonitic skeleton formation in corals as well as possible diagenesis effects. For this purpose, interactions between corals, microborers, and their environment need to be better assessed.
Description of the work: The Post-Doc fellow will develop a mechanistic understanding of elemental and isotopic composition of coral skeleton – with special emphasis on Li/Mg, Sr/Ca and Î´11B – at different stages of coral life cycles. The recruited Post-Doc will subsequently study a coral core from the western equatorial Pacific Ocean covering environmental changes from pre-industrial (low atmospheric CO2) to post-industrial (high atmospheric CO2) eras. The project will also provide a comprehensive calibration of coralsâ€™ geochemical signatures which could be later extended to deep and cold water corals and other calcifiers such as foraminifera.
The recruited Post-doctorate fellow will participate to analytical development using LA-MC-ICP-MS Neptune.
Supervision team: The work will be conducted under the main supervision of D. Dissard and A. Tribollet (UMR LOCEAN) and in close cooperation with researchers/engineers from LSCE (E. Douville, D. Blamart and F. Thil). Other scientists from LOCEAN, LSCE and GEOPS laboratory will also be involved in this research project. The analyses will be undertaken at LOCEAN and LSCE. The candidate will share his time between the two laboratories involved.
Duration and salary: The post-doctorate will be recruited for 18 months starting in early 2015 with a gross monthly salary around 2500 euros, commensurate with experience. This includes social services and health insurance.
Contact for applications: Applications should include a CV, a statement of research interests and the names of at least two references including e-mail addresses and telephone numbers. Applications will be sent to Delphine Dissard and Aline Tribollet ( Delphine.Dissard@locean-ipsl.upmc.fr, Aline.Tribollet@locean-ipsl.upmc.fr).
Closing date: The search will remain open until February 20th 2015.