Understanding the impact of recent ocean acidification on bio-calcification

Pallavi Anand, Phil Sexton, Jelle Bijma (Alfred Wegner Institute, Germany) and Maureen Conte (Bermuda Institute of Ocean Sciences, USA)

  • Field work to collect subtropical Atlantic seafloor surface sediment samples via an internship at Bermuda
  • Training in state-of-the-art micropaleontological and geochemical techniques
  • Reconstruct historical changes in ocean carbonate chemistry caused by recent ocean acidification

Our industrial and agricultural activities have increased atmospheric carbon dioxide (CO2) concentrations from approximately 280 to 387 parts per million (ppm) over the last 200 years. However, over the last two decades, only half of the CO2 released by anthropogenic activities has remained in the atmosphere because significant amounts have been absorbed by the oceans [1] causing a rise in upper Ocean Acidification. The rise in the surface ocean acidity is predicted to cause a reduction in the concentration of carbonate ion in seawater, which is the basic building block of marine calcifiers such as foraminifers. This project will determine recent changes in ocean carbonate ion concentrations by analysing trace element ratios (B/Ca) in planktonic foraminiferal calcite [2], foraminiferal species abundance and shell parameters (mass and size) from sediment trap time series (1984-2008) and sea floor surface sediment samples (available from preindustrial archive and additional sample collection during the project). The project will address the following: The extent to which recent ocean acidification has affected shell calcification of surface dwelling planktonic foraminifera will be addressed by comparing foraminifer trace element and shell mass/size measurements with species abundance, measured seawater carbonate chemistry and calcification temperature (oxygen isotopes and Mg/Ca) data. Quantifying changes in seawater [CO3 2-] due to recent ocean acidification will be achieved by analysing foraminifer B/Ca as a proxy of surface water carbonate ion concentration [2] from seasonally resolved sediment trap samples. Foraminiferal B/Ca will be calibrated against instrumental carbonate system parameters available from nearby locations. In addition, seafloor surface sediment samples will provide a pre-industrial baseline dataset.

The successful candidate will join an active research group specialising in micropaleontology and geochemistry at The Open University where they will receive full training in relevant analytical techniques, as well as in oral and written presentation skills. The successful candidate will benefit from an international team of supervisors, training through an internship at Bermuda and specialist training in trace element geochemistry at collaborating institutes University of Cambridge, UK and Alfred Wegener Institute, Germany. In addition, this project will form a critical part of a number of inter-related international Ocean Acidification programmes including UK Ocean Acidification Research Programme (UKOARP), European Project on OCean Acidification (EPOCA) and Biological Impact of Ocean ACIDification (BIOACID).

The Department has a thriving postgraduate community and the postgraduate training programme provides a full range of courses covering: research techniques, scientific methods, information technology, communication and interpersonal skills, which are tailored to the needs of each student.

If you would like to apply or have any queries about this project please contact the first named supervisor either by email to pallavi.anand@open.ac.uk or by writing to the address above enclosing a full academic CV and the names and addresses of three academic referees.

[1] IPCC Climate Change2007: Imapcts, adaptation and vulnerability, http://www.ipcc-wg2.org (2007) [2] J. Yu, H. Elderfield, B. Hönisch, Paleoceanography, 22, doi:10.1029/2006PA001347 (2007a).

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