I am fascinated by the jigsaw of complex interactions between the evolution of organisms, ocean chemistry, atmospheric composition and Earth’s climate. The extraction of chemical signatures from fossil shells of marine micro-organisms as a tool for constraining past ocean conditions and their influence on climate is fundamental to my research. Yet frustration with the complexities of disentangling the “inorganic” geochemical signal from the overprint of the biomineralising processes has triggered me to seek innovative alternative approaches to constraining past climates and environments. Increasingly I am probing the geological past from the biology of modern day organisms. This ambition broadens into probing biological innovation and environmental change over Earth history since the feedback between the two is inescapable. All modern day organisms have experienced a long evolutionary pathway to arrive at their present incarnation and this history has been accrued to some extent within the genome and physiology of modern day organisms. Indeed such evolutionary history influences the tolerance of different algae to ocean acidification for example, or the trace metal nutrient requirements of different groups of algae across the tree of life. So my approach is to read the geological history of both climate and the chemical environment from signals of adaptation within genes, which plays out in the evolving affinity and kinetics of the expressed enzymes, or isotopic signals of adaptation within biologically relevant molecules.
I lead the OceanBUG research group and my quest for a new proxy based on biological understanding of the signal is reflected in our current projects which include:
Species-specific coccolithophore response to ocean acidification
Lifting the CAP on coccolithophore calcification: characterising acidic polysaccharides which mould the calcite liths of coccolithophores as probes of the past carbon environment
Squelching into the fine mud: dissecting the fine fractions of sediments to read the physiological controls on the isotopes of both coccoliths and diatoms
Characterisation of modern and ancient algal Rubisco with implications for carbon isotopes and acquisition
I spoke about aspects of my work as part of the Royal Society’s Science Stories series:
View Selected Publications
Recent publications include:
1. Hoogakker, Babette A.A., Elderfield, Henry, Schmiedl, Gerard, McCave, I. Nick, Rickaby, R. E.M., Lower glacial North-east Atlantic bottom water oxygen content, Nature Geoscience, 8 (1) 40-43, 2015.
2. Zhou, X.,, Z. Lu, R. E. M. Rickaby, E. W. Domack, J. S. Wellner, H. A. Kennedy, Ikaite abundance controlled by porewater phosphorus level: potential links to dusk and productivity, Journal of Geology, 123 269-281. 2015.
3. Omta, A.W., Kooi, B.W., van Voorn, G.A.K., Rickaby, R.E.M., Follows, M.J., Inherent characteristics of sawtooth cycles can explain different glacial periodicities, Climate Dynamics, 2015.
4. Rickaby, R. E. M., Goldilocks and the three inorganic equilibria: how Earth’s chemistry and life co-evolve to be nearly in tune, Phil. Trans. Roy. Soc. A, 373 (2037) 2015.
5. Heureux, A. M., and Rickaby, R. E. M. Refining our estimate of atmospheric CO2 across the Eocene-Oligocene climatic transition, Accepted EPSL.
6. X. Zhou, E. Thomas, R. E.M. Rickaby, A.M.E. Winguth and Z. Lu, I/Ca evidence for upper ocean deoxygenation during the Paleocene-Eocene Thermal Maximum (PETM), Paleoceanography 1 OCT 2014; DOI: 10.1002/2014PA002702
7. Krueger-Hadfield et al., “Genotyping an Emiliania huxleyi (Prymnesiophyceae) bloom event in the North Sea reveals evidence of asexual reproduction “Genotyping an Emiliania huxleyi (Prymnesiophyceae) bloom event in the North Sea reveals evidence of asexual reproduction, Biogeosciences, 11, 5215-5234, 2014
8. Hermoso, M., T. J. Horner, F. Minoletti, R. E. M. Rickaby, Constraints on the vital effect in coccolithophore and dinoflagellate calcite by oxygen isotopic modification of seawater GCA, 141, 612-627, 2014.
9. Winter A., J. Henderiks, L. Beaufort, R. E. M. Rickaby, C. W. Brown, Poleward expansion of the coccolithophore Emiliania huxleyi, Journal of Plankton Research, 36, 316-325, 2014
10. Stevenson, E. I., M. Hermoso R. E. M. Rickaby, J. J. Tyler, I. J. Parkinson, F. Mokadem, and K. W. Burton, Controls on Stable strontium isotope fractionation in coccolithophores with implications for the marine Sr cycle, Geochim. Et Cosmochim. Acta, 128, 225-235, 2014
11. Trueman, C. N.; Rickaby, R. E. M.; Shephard, S., Thermal, trophic and metabolic life histories of inaccessible fishes revealed from stable- isotope analyses: a case study using orange roughy Hoplostethus atlanticus, J. Fish Biology, 83, 1613-1636, 2013
12. Horner, T. J., R. B. Y. Lee, G. M. Henderson, R. E. M. Rickaby, Reply to Morel, 2013
13. Horner, T. J., R. B. Y. Lee, G. M. Henderson, R. E. M. Rickaby, Unavoidable uptake and homeostasis drives the oceanic cadmium cycle, PNAS, 110, 2500-2505, 2013
14. C. V. Ullmann, F. Böhm, R. E. M. Rickaby, U. Wiechert, C. Korte, The Giant Pacific Oyster (Crassostrea gigas) as a modern analog for fossil ostreoids: Isotopic (Ca, O, C) and elemental (Mg/Ca, Sr/Ca, Mn/Ca) proxies, Geochemistry, Geophysics, Geosystems 14 (10), 4109-4120, 2013
15. Egan, K., R. E. M. Rickaby, K. R. Hendry, A. N. Halliday, Opening the gateways for diatoms primes Earth for Antarctic glaciation, Earth and Planet. Sci. Letts., 375, 34-43, 2013
16. Omta, A-W., G. A. K. Van Voorn, R. E. M. Rickaby, M. J Follows, On the potential role of marine calcifiers in glacial-interglacial dynamics, Global Biogeochemical Cycles, 27, 692-704, 2013
17. Young, J. N., Bruggeman, J., Rickaby, R. E. M., J. Erez, M. H. Conte, Evidence for changes in carbon isotopic fractionation by phytoplankton between 1960 and 2010, Global Biogeochemical Cycles, 27, 505-515, 2013
18. Johnson VR, Brownlee, C, Rickaby REM, Graziano M, Milazzo M & Hall-Spencer, JM Responses of marine benthic microalgae to elevated CO2. Marine Biology, 160, 1813-1824, 2013
19. Lee, R., Rickaby, R. E. M., A. J. Smith, Cloning, expression and (functional) characterisation of the Thalassiosira Weissflogii d-Carbonic Anhydrase, Journal of Phycology, 49, 170-177, 2013
20. Egan, K., Rickaby, R. E. M., M. J. Leng, K. R. Hendry, M. Hermoso, H. J. Sloane, H. Bostock, and A. N. Halliday, Diatom Silicon Isotopes as a Proxy for Silicic Acid Utilisation: Southern Ocean Core Top Calibration, Geochim., Cosmochim. Acta, doi.org/10.1016/j.gca.2012.08.002, 2012
21. R. J. P. Williams and R. E. M. Rickaby, A chemical Account of Evolution, Chemistry World.
And I even co-wrote a book:
Williams, R. J. P., and Rickaby R. E. M., Evolution’s Destiny: Co-evolving Chemistry of the Environment and Life