Dr Christina McGraw

Adjunct Senior Lecturer - School of Science and Technology


I obtained my PhD in Analytical Chemistry in 2004 from the University of Washington (Seattle, Washington, USA) with Professor James B. Callis, where I developed thin-film microphones, wind tunnel models, oxygen-sensitive paints, and sensors to study insect flight.

My first post-doctoral position was at Ireland’s National Centre for Sensor Research, where I developed autonomous sensors for soil and freshwater monitoring. My second post-doctoral position was at the University of Otago (New Zealand), where I develop instrumentation to study the effects of climate change on the oceans. Before moving to Armidale in 2013, I was an Assistant Professor of Environmental Analytical chemistry at Clark University.


PhD (Analytical Chemistry) University of Washington, Seattle, Washington, USA

Teaching Areas

Research Interests

The effect of anthropogenic CO2 on our marine ecosystems

Since the industrial revolution, the oceans have absorbed about 1/3 of the anthropogenic CO2 released to the atmosphere. While this has reduced the effect of CO2 emissions on climate change, it is also changing the chemistry of the world's oceans.

When CO2 is absorbed by seawater it forms carbonic acid (H2CO3) which dissociates to H+ and bicarbonate (HCO3-). The H+ reacts with carbonate ions (CO32-), forming additional bicarbonate. The net reaction, referred to as ocean acidification, is to increase the concentration of H+ (decreasing the seawater pH) and to reduce the concentration of carbonate. Our group is developing new field-deployable sensors to measure fine-scale changes in carbonate chemistry and to study ocean acidification's impact on the structure of vulnerable calcifying organisms.


Selected Publications

P.W. Boyd, P.W. Dillingham, C.M. McGraw, E.A. Armstrong, C.E. Cornwall, Y-y Feng, C.L. Hurd, M. Gault-Ringold, M.Y. Roleda, E. Timmins-Schiffman, B.L. Nunn, Physiological responses of a Southern Ocean diatom to complex future ocean conditions, Nature Climate Change, doi:10.1038/nclimate2811 (2015)

M.Y. Roleda, C.E. Cornwall, Y. Feng, C.M. McGraw, A.M. Smith, C.L. Hurd, Effect of Ocean Acidification and pH Fluctuations on the Growth and Development of Coralline Algal Recruits, and an Associated Benthic Algal Assemblage, PloS ONE 10(10), e0140394 (2015)

L Mendecki, T Fayose, KA Stockmal, J Wei, S Granados-Focil, C.M. McGraw, A. Radu, Robust and ultrasensitive polymer membrane-based carbonate-selective electrodes, Analytical chemistry 87 (15), 7515-7518

C.E. Cornwall, P.W. Boyd, C.M. McGraw, C.D. Hepburn, C.A. Pilditch, J.N. Morris, A.M. Smith, C.L. Hurd, Diffusion Boundary Layers Ameliorate the Negative Effects of Ocean Acidification on the Temperate Coralline Macroalga Arthrocardia corymbosa, PLoS ONE, 9(5): e97235 (2014)

R.K. James, C.D. Hepburn, C.E. Cornwall, C.M. McGraw, C.L. Hurd, Growth response of an early successional assemblage of coralline algae and benthic diatoms to ocean acidification, Marine Biology, 1-10, doi: 10.1007/s00227-014-2453-3 (2014)

C.E. Cornwall, C.D. Hepburn, C.M. McGraw, C.I. Currie, C.A. Pilditch, K.A. Hunter, P.W. Boyd, C.L. Hurd, Diurnal fluctuations in seawater pH influence the response of a calcifying macroalga to ocean acidification, Proceedings of the Royal Society B, 280: 1772, (2013)

K. Baer Jones, K. Currie, C.M. McGraw, K. Hunter, Spatial and temporal variations in phytoplankton primary production and chl-a across the coastal Subtropical Frontal Zone, Estuarine, Coastal and Shelf Science, 124: 44-55 (2013)

C. Law, E. Breitbarth, L. Hoffmann, C. McGraw, R. Langlois, J. LaRoche, A. Marriner, K. Safi, No stimulation of nitrogen fixation by non-filamentous diazotrophs under elevated CO2 in the South Pacific, Global Change Biology, 18(10): 3004-3014 (2012)

M.Y. Roleda, J.N. Morris, C.M. McGraw, C.L. Hurd, Ocean acidification and seaweed reproduction: increased CO2 ameliorates the negative effect of lowered pH on meiospore germination in the giant kelp Macrocystis pyrifera (Laminariales, Phaeophyceae), Global Change Biology, 18(3): 854-864 (2012)

P.W. Dillingham, T. Radu, D. Diamond, A. Radu, C.M. McGraw, Bayesian Methods for Ion Selective Electrodes, Electroanalysis, 24(2): 316-324 (2012)

C. Cornwall, C.D. Hepburn, D. Pritchard, K. Currie, C.M. McGraw, K.A. Hunter, C.L. Hurd, Carbon-use strategies in macroalgae: differential responses low lowered pH and implications for ocean acidification, Journal of Phycology, 48(1): 137-144 (2012)