PhD, MSc (Washington)
Tel +64 3 479 7907
Location Science II, 5c4
Email christina.mcgraw@otago.ac.nz
For more information about the McGraw Research Group
https://blogs.otago.ac.nz/christinamcgraw/
Professional background
2017 – present, Senior Lecturer, University of Otago
2015 – 2016, Lecturer, University of New England, Australia
2013 – 2016, Visiting Lecturer and Biogeochemical Sensor Developer, Institute for Marine and Antarctic Studies, Australia
2011 – 2013, Assistant Professor of Environmental Analytical Chemistry, Clark University, USA
2006 – 2010, Postdoctoral Fellow, University of Otago
2005 – 2006, Postdoctoral Fellow, Dublin City University
1999 – 2004, Ph.D. (Analytical Chemistry) and M.Sc., University of Washington, USA
1999 – BSc (Chemistry), University of Alaska, USA
Research interests
With broad interests in analytical and marine chemistry, my research revolves around the design of field-deployable instrumentation for marine ecosystems.
Christina is also a member of the Coastal People: Southern Skies collaboration that connects communities with world-leading, cross-discipline research to rebuild coastal ecosystems.
Coastal People: Southern Skies
Current research projects include:
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 into the atmosphere. This decreases both seawater pH and carbonate concentration, significantly altering the chemistry of the world's oceans. Our group is developing new laboratory instruments and field-deployable sensors to measure fine-scale changes in carbonate chemistry and to study the impact of global climate change on the world’s oceans.
Deployable environmental sensors
To understand fine-scale spatial and temporal changes, solid-contact fabrication techniques have been used to produce a range of low-cost, disposable ion-selective sensors, including carbonate, pH, lead, cadmium, nitrate, and reference electrodes.
Materials and methods for ion-selective electrodes
New methods for ion-selective electrode (ISE) construction are being used to reduce ion fluxes across the sensor’s membrane, leading to 100-to-1000-fold improvements in detection limit. This work is complemented by new Bayesian models of the sensor’s response, which further improves the accuracy and precision of the measurement.
Publications
Hong, C. Y., Fletcher, D., Zeng, J., McGraw, C. M., Cornwall, C. E., Cummings, V. J., … Dillingham, P. W. (2023). Efficient analysis of split-plot experimental designs using model averaging. Journal of Quality Technology. Advance online publication. doi: 10.1080/00224065.2022.2147108
Dixon-Anderson, I. S., McGraw, C. M., & Smith, A. M. (2022). Variable [Mg2+] in seawater forces mineralogy change in Spirobranchus cariniferus calcification. Marine Chemistry. Advance online publication. doi: 10.1016/j.marchem.2022.104111
Britton, D., Schmid, M., Mundy, C., Noisette, F., Havenhand, J., Paine, E., McGraw, C., … Hurd, C. (2021). Contrasting responses of two keystone seaweeds to ocean global change in southeastern Australia. Phycologia, 60(Suppl. 1), (pp. 101). doi: 10.1080/00318884.2021.1922050
Muetzel, L. K., Dillon, W. D. N., Currie, K., & McGraw, C. M. (2021). NZOA monitoring program unaffected by [Ca2+]-salinity variability. Proceedings of the 14th Annual New Zealand Ocean Acidification Conference: Ocean Acidification in a Decade of Ocean Science. (pp. 26). Retrieved from http://nzoac.nz/conferences
Cowley, G. T., McGraw, C. M., & Hoffmann, L. J. (2021). Environmental science in civic society and policy: Outreach for a better world today. Proceedings of the 14th Annual New Zealand Ocean Acidification Conference: Ocean Acidification in a Decade of Ocean Science. (pp. 25). Retrieved from http://nzoac.nz/conferences
Hong, C. Y., Fletcher, D., Zeng, J., McGraw, C. M., Cornwall, C. E., Cummings, V. J., … Dillingham, P. W. (2023). Efficient analysis of split-plot experimental designs using model averaging. Journal of Quality Technology. Advance online publication. doi: 10.1080/00224065.2022.2147108
Journal - Research Article
Dixon-Anderson, I. S., McGraw, C. M., & Smith, A. M. (2022). Variable [Mg2+] in seawater forces mineralogy change in Spirobranchus cariniferus calcification. Marine Chemistry. Advance online publication. doi: 10.1016/j.marchem.2022.104111
Journal - Research Article
Chen, W.-H., Dillon, W. D. N., Armstrong, E. A., Moratti, S. C., & McGraw, C. M. (2021). Self-referencing optical fiber pH sensor for marine microenvironments. Talanta, 225, 121969. doi: 10.1016/j.talanta.2020.121969
Journal - Research Article
Alsaedi, B. S. O., McGraw, C. M., Schaerf, T. M., & Dillingham, P. W. (2020). Multivariate limit of detection for non-linear sensor arrays. Chemometrics & Intelligent Laboratory Systems, 201, 104016. doi: 10.1016/j.chemolab.2020.104016
Journal - Research Article
Britton, D., Schmid, M., Noisette, F., Havenhand, J. N., Paine, E. R., McGraw, C. M., … Hurd, C. L. (2020). Adjustments in fatty acid composition is a mechanism that can explain resilience to marine heatwaves and future ocean conditions in the habitat-forming seaweed Phyllospora comosa (Labillardiere) C.Agardh. Global Change Biology, 26, 3512-3524. doi: 10.1111/gcb.15052
Journal - Research Article
Dillingham, P. W., Alsaedi, B. S. O., Granados-Focil, S., Radu, A., & McGraw, C. M. (2020). Establishing meaningful limits of detection for ion-selective electrodes and other nonlinear sensors. ACS Sensors, 5, 250-257. doi: 10.1021/acssensors.9b02133
Journal - Research Article
Dillon, W. D. N., Dillingham, P. W., Currie, K. I., & McGraw, C. M. (2020). Inclusion of uncertainty in the calcium-salinity relationship improves estimates of ocean acidification monitoring data quality. Marine Chemistry, 226, 103872. doi: 10.1016/j.marchem.2020.103872
Journal - Research Article
Ellwood, M. J., Boyd, P. W., Cornwall, C. E., Croot, P., Currie, K. I., Frew, R. D., … Law, C., … McGraw, C. M., … Stirling, C., & Zitoun, R. (2020). Keith Hunter's legacy to marine science in New Zealand. Marine & Freshwater Research, 71(3), i-iii. doi: 10.1071/MFv71n3_ED
Journal - Research Article
Britton, D., Mundy, C. N., McGraw, C. M., Revill, A. T., & Hurd, C. L. (2019). Responses of seaweeds that use CO2 as their sole inorganic carbon source to ocean acidification: Differential effects of fluctuating pH but little benefit of CO2 enrichment. ICES Journal of Marine Science, 76(6), 1860-1870. doi: 10.1093/icesjms/fsz070
Journal - Research Article
Dillingham, P. W., Alsaedi, B. S. O., Radu, A., & McGraw, C. M. (2019). Semi-automated data analysis for ion-selective electrodes and arrays using the R package ISEtools. Sensors, 19(4544). doi: 10.3390/s19204544
Journal - Research Article
van der Loos, L. M., Schmid, M., Leal, P. P., McGraw, C. M., Britton, D., Revill, A. T., … Hurd, C. L. (2019). Responses of macroalgae to CO2 enrichment cannot be inferred solely from their inorganic carbon uptake strategy. Ecology & Evolution, 9(1), 125-140. doi: 10.1002/ece3.4679
Journal - Research Article
Reidenbach, L. B., Fernandez, P. A., Leal, P. P., Noisette, F., McGraw, C. M., Revill, A. T., Hurd, C. L., & Kübler, J. E. (2017). Growth, ammonium metabolism, and photosynthetic properties of Ulva australis (Chlorophyta) under decreasing pH and ammonium enrichment. PLoS ONE, 12(11), e0188389. doi: 10.1371/journal.pone.0188389
Journal - Research Article
Boyd, P. W., Dillingham, P. W., McGraw, C. M., Armstrong, E. A., Cornwall, C. E., Feng, Y.-y., Hurd, C. L., Gault-Ringold, M., Roleda, M. Y., … Nunn, B. L. (2016). Physiological responses of a Southern Ocean diatom to complex future ocean conditions. Nature Climate Change, 6, 207-213. doi: 10.1038/NCLIMATE2811
Journal - Research Article
Mendecki, L., Fayose, T., Stockmal, K. A., Wei, J., Granados-Focil, S., McGraw, C. M., & Radu, A. (2015). Robust and ultrasensitive polymer membrane-based carbonate-selective electrodes. Analytical Chemistry, 87(15), 7515-7518. doi: 10.1021/acs.analchem.5b01756
Journal - Research Article
Roleda, M. Y., Cornwall, C. E., Feng, Y., McGraw, C. M., Smith, A. M., & Hurd, C. L. (2015). 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. doi: 10.1371/journal.pone.0140394
Journal - Research Article
Cornwall, C. E., Boyd, P. W., McGraw, C. M., Hepburn, C. D., Pilditch, C. A., Morris, J. N., Smith, A. M., & Hurd, C. L. (2014). Diffusion boundary layers ameliorate the negative effects of ocean acidification on the temperate coralline macroalga Arthrocardia corymbosa. PLoS ONE, 9(5), e97235. doi: 10.1371/journal.pone.0097235
Journal - Research Article
James, R. K., Hepburn, C. D., Cornwall, C. E., McGraw, C. M., & Hurd, C. L. (2014). Growth response of an early successional assemblage of coralline algae and benthic diatoms to ocean acidification. Marine Biology, 161(7), 1687-1696. doi: 10.1007/s00227-014-2453-3
Journal - Research Article
Cornwall, C. E., Hepburn, C. D., McGraw, C. M., Currie, K. I., Pilditch, C. A., Hunter, K. A., Boyd, P. W., & Hurd, C. L. (2013). Diurnal fluctuations in seawater pH influence the response of a calcifying macroalga to ocean acidification. Proceedings of the Royal Society B, 280, 20132201. doi: 10.1098/rspb.2013.2201
Journal - Research Article
Hoffmann, L. J., Breitbarth, E., McGraw, C. M., Law, C. S., Currie, K. I., & Hunter, K. A. (2013). A trace-metal clean, pH-controlled incubator system for ocean acidification incubation studies. Limnology & Oceanography: Methods, 11, 53-61. doi: 10.4319/lom.2013.11.53
Journal - Research Article
Jones, K. N., Currie, K. I., McGraw, C. M., & Hunter, K. A. (2013). The effect of coastal processes on phytoplankton biomass and primary production within the near-shore Subtropical Frontal Zone. Estuarine, Coastal & Shelf Science, 124, 44-55. doi: 10.1016/j.ecss.2013.03.003
Journal - Research Article
Radu, A., Radu, T., McGraw, C., Dillingham, P., Anastasova-Ivanova, S., & Diamond, D. (2013). Ion selective electrodes in environmental analysis. Journal of the Serbian Chemical Society, 78, 1729-1761. doi: 10.2298/JSC130829098R
Journal - Research Article
Cornwall, C. E., Hepburn, C. D., Pritchard, D., Currie, K. I., McGraw, C. M., Hunter, K. A., & Hurd, C. L. (2012). Carbon-use strategies in macroalgae: Differential responses to lowered pH and implications for ocean acidification. Journal of Phycology, 48(1), 137-144. doi: 10.1111/j.1529-8817.2011.01085.x
Journal - Research Article
Dillingham, P. W., Radu, T., Diamond, D., Radu, A., & McGraw, C. M. (2012). Bayesian methods for ion selective electrodes. Electroanalysis, 24(2), 316-324. doi: 10.1002/elan.201100510
Journal - Research Article
Law, C. S., Breitbarth, E., Hoffmann, L. J., McGraw, C. M., Langlois, R. J., LaRoche, J., … Safi, K. A. (2012). No stimulation of nitrogen fixation by non-filamentous diazotrophs under elevated CO2 in the South Pacific. Global Change Biology, 18(10), 3004-3014. doi: 10.1111/j.1365-2486.2012.02777.x
Journal - Research Article
Roleda, M. Y., Morris, J. N., McGraw, C. M., & Hurd, C. L. (2012). 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. doi: 10.1111/j.1365-2486.2011.02594.x
Journal - Research Article
Cummings, V., Hewitt, J., Van Rooyen, A., . . ., Gomez, A., McGraw, C., & Metcalf, V. (2011). Ocean acidification at high latitudes: Potential effects on functioning of the Antarctic bivalve Laternula elliptica. PLoS ONE, 6(1), e16069. doi: 10.1371/journal.pone.0016069
Journal - Research Article
Hurd, C. L., Cornwall, C. E., Currie, K., Hepburn, C. D., McGraw, C. M., Hunter, K. A., & Boyd, P. W. (2011). Metabolically induced pH fluctuations by some coastal calcifiers exceed projected 22nd century ocean acidification: A mechanism for differential susceptibility? Global Change Biology, 17, 3254-3262. doi: 10.1111/j.1365-2486.2011.02473.x
Journal - Research Article
McGraw, C. M., Cornwall, C. E., Reid, M. R., Currie, K. I., Hepburn, C. D., Boyd, P., Hurd, C. L., & Hunter, K. A. (2010). An automated pH-controlled culture system for laboratory-based ocean acidification experiments. Limnology & Oceanography: Methods, 8, 686-694. doi: 10.4319/lom.2010.8.686
Journal - Research Article
Cleary, J. J., Slater, C., McGraw, C., & Diamond, D. (2008). An autonomous microfluidic sensor for phosphate: On-site analysis of treated wastewater. IEEE Sensors Journal, 8(5), 508-515.
Journal - Research Article
McGraw, C. M., Khalil, G., & Callis, J. B. (2008). Comparison of time and frequency domain methods for luminescence lifetime measurements. Journal of Physical Chemistry C, 112(21), 8079-8084.
Journal - Research Article
McGraw, C. M., Radu, T., Radu, A., & Diamond, D. (2008). Evaluation of liquid- and solid-contact, Pb2+-selective polymer-membrane electrodes for soil analysis. Electroanalysis, 20(3), 340-346.
Journal - Research Article
McGraw, C. M., Stitzel, S. E., Cleary, J., Slater, C., & Diamond, D. (2007). Autonomous microfluidic system for phosphate detection. Talanta, 71(3), 1180-1185. doi: 10.1016/j.talanta.2006.06.011
Journal - Research Article
McGraw, C. M., Bell, J. H., Khalil, G., & Callis, J. B. (2006). Dynamic surface pressure measurements on a square cylinder with pressure sensitive paint. Experiments in Fluids, 40, 203-211. doi: 10.1007/s00348-005-0059-8
Journal - Research Article
Hurd, C. L., Beardall, J., Comeau, S., Cornwall, C. E., Havenhand, J. N., Munday, P. L., … McGraw, C. M. (2020). Ocean acidification as a multiple driver: How interactions between changing seawater carbonate parameters affect marine life. Marine & Freshwater Research, 71, 263-274. doi: 10.1071/MF19267
Journal - Research Other
Boyd, P. W., Collins, S., Dupont, S., Fabricius, K., Gattuso, J.-P., Havenhand, J., … McGraw, C. M., … Pörtner, H.-O. (2018). Experimental strategies to assess the biological ramifications of multiple drivers of global ocean change: A review. Global Change Biology, 24(6), 2239-2261. doi: 10.1111/gcb.14102
Journal - Research Other
Dillingham, P. W., Alsaedi, B. S. O., & McGraw, C. M. (2017). Characterising uncertainty in instrumental limits of detection when sensor response is non-linear. Proceedings of the IEEE Sensors Conference. (pp. 94-96). IEEE. doi: 10.1109/ICSENS.2017.8233898
Conference Contribution - Published proceedings: Full paper
Britton, D., Schmid, M., Mundy, C., Noisette, F., Havenhand, J., Paine, E., McGraw, C., … Hurd, C. (2021). Contrasting responses of two keystone seaweeds to ocean global change in southeastern Australia. Phycologia, 60(Suppl. 1), (pp. 101). doi: 10.1080/00318884.2021.1922050
Conference Contribution - Published proceedings: Abstract
Chen, W.-H., Dillon, W. D. N., Armstrong, E. A., Moratti, S. C., & McGraw, C. M. (2021). Optical fiber pH sensor for marine microenvironments. Proceedings of the 14th Annual New Zealand Ocean Acidification Conference: Ocean Acidification in a Decade of Ocean Science. (pp. 23). Retrieved from http://nzoac.nz/conferences
Conference Contribution - Published proceedings: Abstract
Christensen, T. J. E., Zitoun, R., Hoffmann, L. J., Dillon, W. D. N., Dillingham, P. W., & McGraw, C. M. (2021). Redefining Ksp for calcite and aragonite with lower uncertainty in artificial seawater. Proceedings of the 14th Annual New Zealand Ocean Acidification Conference: Ocean Acidification in a Decade of Ocean Science. (pp. 24). Retrieved from http://nzoac.nz/conferences
Conference Contribution - Published proceedings: Abstract
Cowley, G. T., McGraw, C. M., & Hoffmann, L. J. (2021). Environmental science in civic society and policy: Outreach for a better world today. Proceedings of the 14th Annual New Zealand Ocean Acidification Conference: Ocean Acidification in a Decade of Ocean Science. (pp. 25). Retrieved from http://nzoac.nz/conferences
Conference Contribution - Published proceedings: Abstract
Dillingham, P. W., Hong, C. Y., Cornwall, C. E., Fletcher, D., McGraw, C. M., & Zeng, J. (2021). Multi-driver experiments with different scales of replication. Proceedings of the 14th Annual New Zealand Ocean Acidification Conference: Ocean Acidification in a Decade of Ocean Science. (pp. 13). Retrieved from http://nzoac.nz/conferences
Conference Contribution - Published proceedings: Abstract
Dillon, W. D. N., Dillingham, P. W., Currie, K. I., & McGraw, C. M. (2021). The calcium-salinity relationship: An underappreciated detail in coastal ocean acidification monitoring and data quality. Proceedings of the 14th Annual New Zealand Ocean Acidification Conference: Ocean Acidification in a Decade of Ocean Science. (pp. 9). Retrieved from http://nzoac.nz/conferences
Conference Contribution - Published proceedings: Abstract
Dupont, S., Cornwall, C., & McGraw, C. (2021). Do you (really) know your multiple stressors? Proceedings of the 14th Annual New Zealand Ocean Acidification Conference: Ocean Acidification in a Decade of Ocean Science. (pp. 11). Retrieved from http://nzoac.nz/conferences
Conference Contribution - Published proceedings: Abstract
Muetzel, L. K., Dillon, W. D. N., Currie, K., & McGraw, C. M. (2021). NZOA monitoring program unaffected by [Ca2+]-salinity variability. Proceedings of the 14th Annual New Zealand Ocean Acidification Conference: Ocean Acidification in a Decade of Ocean Science. (pp. 26). Retrieved from http://nzoac.nz/conferences
Conference Contribution - Published proceedings: Abstract
Chen, D. W. H., & McGraw, C. (2019). Fibre optic pH microsensor for studying the impact of ocean acidification on the marine environment. Proceedings of the 12th New Zealand Ocean Acidification Workshop. (pp. 48). Retrieved from http://nzoac.nz
Conference Contribution - Published proceedings: Abstract
Dillon, W. D. N., Law, C. S., & McGraw, C. M. (2019). A deployable saturation state sensor towards global ocean monitoring. Proceedings of the 12th New Zealand Ocean Acidification Workshop. (pp. 29). Retrieved from http://nzoac.nz
Conference Contribution - Published proceedings: Abstract
Hashemi, S., Seah, N., Chen, D. W. H., Hermansson, A. L., Dillon, W., Currie, K., & McGraw, C. (2019). Refining low-cost carbonate ion selective electrodes for 2D profiling. Proceedings of the 12th New Zealand Ocean Acidification Workshop. (pp. 49). Retrieved from http://nzoac.nz
Conference Contribution - Published proceedings: Abstract
Law, C., Gall, M., Barr, N., McGraw, C., Dillon, W., Bianchi, M., … Farrington, G. (2019). Mitigating low pH for the mussel aquaculture industry. Proceedings of the 12th New Zealand Ocean Acidification Workshop. (pp. 26). Retrieved from http://nzoac.nz
Conference Contribution - Published proceedings: Abstract
Lunde Hermansson, A., Dillon, W., Smith, A. M., Dillingham, P., & McGraw, C. (2019). Solubility of natural carbonate samples. Proceedings of the 12th New Zealand Ocean Acidification Workshop. (pp. 43). Retrieved from http://nzoac.nz
Conference Contribution - Published proceedings: Abstract
Meyers, M., McGraw, C., Décima, M., & Hoffmann, L. (2019). Design and employment of a new portable CO2 system for ocean acidification experiments. Proceedings of the 12th New Zealand Ocean Acidification Workshop. (pp. 50). Retrieved from http://nzoac.nz
Conference Contribution - Published proceedings: Abstract