Details of Award
NERC Reference : NE/H015523/1
Developing a mechanistic understanding of stable isotopes in coccolithophores: a culture and field approach
Fellowship Award
- Fellow:
- Professor M Hermoso, University of Oxford, Earth Sciences
- Grant held at:
- University of Oxford, Earth Sciences
- Science Area:
- Terrestrial
- Marine
- Freshwater
- Earth
- Atmospheric
- Overall Classification:
- Marine
- ENRIs:
- Global Change
- Biodiversity
- Science Topics:
- Ocean - Atmosphere Interact.
- Sediment/Sedimentary Processes
- Palaeoenvironments
- Climate & Climate Change
- Abstract:
- The surface ocean is a foremost actor in the exchange between the deep oceanic reservoir of carbon and the atmosphere. The balance between the CO2 incomes from volcanism and the CO2 drawdown in the ocean and seafloor dictates the content in the atmospheric carbon dioxide, which has implication on the climate on Earth. Our knowledge on past climates mostly relies on the analyses of the evolution of the marine organisms that compose this 'biological pump' including the use of geochemical tools such as trace metals or stable isotopes recorded by their mineralized remains and preserved in the sedimentary archive. However, the manner in which the climate and the composition of seawater are recorded in the sediments is not completely faithful. The physiology of the actors of the biological pump, the oceanic plankton, is prone to substantively biase the geochemical record by a process termed 'vital effect' in the literature. The aim of the proposed work is to examine and quantify this distortion in order to be able to reconstruct climates more reliably. I have chosen to study the coccolithophores, unicellular photosynthetic marine algae living in the surface of the oceans, because they have an influential role on the exchange of CO2 between the atmosphere and the ocean, and are responsible for a large part of the carbon drawdown to the seafloor. These micro-organisms are easy to grow in the laboratory. So it is possible to reproduce in vitro some environmental changes in the seawater chemistry by modifying the composition of the culturing medium. By these experiments, I will seek the effect of the changes in the chemical composition of the biominerals and measure the intensity of the vital effect. This will enable identifying what causes them and developing a quantitative approach. Once such a calibration between extracellular parameters and the geochemistry of the mineralisation is obtained, I will test this outcomes pertaining the biogeochemistry of these organisms against the climatic variability of natural environment both geographically and temporally. To do so, I will study core tops and core sediments from the last glacial maximum from which I will separate various coccolith species (the calcareous remains of coccolithophores in the sediment). Taken together, these data will allow unlocking a part of the information contained in the geological record and derive actual variations of the chemistry of seawater in the past. These new constrains will also be relevant for predicting the response of the oceanic carbonate system to future climate changes because the behaviour of the surface ocean is a key parameter used for most climatic models.
- NERC Reference:
- NE/H015523/1
- Grant Stage:
- Completed
- Scheme:
- Postdoctoral Fellow (FEC)
- Grant Status:
- Closed
- Programme:
- Postdoctoral Fellowship
This fellowship award has a total value of £292,192
FDAB - Financial Details (Award breakdown by headings)
| DI - Other Costs | Indirect - Indirect Costs | DA - Estate Costs | DI - Staff | DI - T&S | DA - Other Directly Allocated |
|---|---|---|---|---|---|
| £26,606 | £119,387 | £32,028 | £103,350 | £7,700 | £3,120 |
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