Claire P. Till
My research focuses on measuring trace concentrations of metals in the marine environment and investigating how these trace metals impact or provide insights into biological, chemical and physical systems. Many trace metals are key micronutrients for phytoplankton; others (at sufficient concentration) are toxic; others are “tracers” that allow us to follow chemical and physical processes in the ocean.
Analyzing metals at trace concentrations is an analytical challenge: samples are both hard to measure and easy to contaminate. In my lab we employ analytical techniques to concentrate the metals of interest before instrumental analysis. To avoid contamination, we work carefully under filtered air to minimize the possibility of even a dust particle getting into our samples.
Much of our work has focused on iron and the lesser known element scandium. See examples of our research on scandium and iron in the ocean here:
a talk I gave at the Exploratorium in San Francisco as part of their series "Everything Matters: Tales from the Periodic Table" in 2017: https://www.youtube.com/watch?v=WwFu07njTGk
a talk as part of Cal Poly Humboldt's Sponsored Programs Foundation McCrone Awards Ceremony in 2021: https://youtu.be/dKQwj9x_0b4?t=2023
Also check out this fun and interesting article on scandium: https://www.nature.com/articles/nchem.2090.
Current and Past Funded Projects
Cottrell Scholar Award, Scandium and Iron: Parallels in Chemical Reactivity, and Reducing the Opportunity Gap in the Cal Poly Humboldt Chemistry Department and Beyond, 2020-2024
National Science Foundation, Collaborative Research: U.S. GEOTRACES PMT: Dissolved trace metal distributions and size partitioning (Fe, Mn, Zn, Cu, Cd, Ni, Pb, & Sc), 2017-2021
Specialty Area
Analytical Chemistry, Chemical Oceanography, Biogeochemical Cycling of Trace Metals
Education
Ph.D. Ocean Science (2016), University of California Santa Cruz, Santa Cruz, California
B.S. Chemistry (2011), Bates College, Lewiston, Maine
Courses Taught
General Chemistry (CHEM 109, CHEM 110)
Quantitative Analysis (CHEM 341)
Instrumental Analysis (CHEM 441)
Earth System Chemistry (CHE 370)
Publications
Cal Poly Humboldt undergraduate student authors indicated with *.
26. Lin, Y.Y., O. Torano, L.Whitehouse, E. Pierce, C.P. Till, M. Hurst, R. Freiberger*, T. Mellett, M.T. Maldonado, J. Guo, M. Sutton, D. Zeitz*, and A. Marchetti (2024) Variability in the phytoplankton response to upwelling across an iron limitation mosaic within the California current system, Limnology and Oceanography, 1-14, doi:10.1002/lno.12534.
25. *Moore, J and C.P. Till (2023) Approaches to Assessing Nutrient Coupling in Open Ocean Datasets, IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt, 7(2). Available at: https://digitalcommons.humboldt.edu/ideafest/vol7/iss1/2/
24. Abdala, Z.M., S. Clayton, S.V. Einarsson, K. Powell, C.P. Till, T.H. Coale and P.D. Chappell (2022) Examining ecological succession of diatoms in California Current System cyclonic mesoscale eddies, Limnology and Oceanography, 1-17, doi:10.1002/lno.12224.
23. *Miller, K.E., C.J. Strait*, J.I. Begorre*, B.L. Mitchell* and C.P. Till (2022) Concentration of Heavy Metals in Three Distinct Algae Families from Humboldt County, California, IdeaFest: Interdisciplinary Journal of Creative Works and Research from Cal Poly Humboldt, 6(6). Available at: https://digitalcommons.humboldt.edu/ideafest/vol6/iss1/6
22. Marsay, C.M., W.M. Landing, D. Umstead, C.P. Till, R. Freiberger*, J.N. Fitzsimmons, N.T. Lanning, A.M. Shiller, M. Hatta, R. Chmiel, M. Saito and C.S. Buck (2022) Does sea-spray aerosol contribute significantly to aerosol trace element loading? A case study from the U.S. GEOTRACES Pacific Meridional Transect (GP15), Global Biogeochemical Cycles, doi:10.1029/2022GB007416.
21. Maniscalco, M.A., M.A. Brzezinski, R.H. Lampe, N.R. Cohen, H.M. McNair, K.A. Ellis, M. Brown, C.P. Till, B.S. Twining, K.W. Bruland, A. Marchetti and K. Thamatrakoln (2022), Diminished carbon and nitrate assimilation drive changes in diatom elemental stoichiometry independent of silicification in an iron-limited assemblage, ISME Communications, 2, 57, doi:10.1038/s43705-022-00136-1.
20. Kranzler, C.F., M.A. Brzezinski, N.R. Cohen, R.H. Lampe, M. Maniscalco, C.P. Till, J. Mack, J.R. Latham, K.W. Bruland, B.S. Twining, A. Marchetti and K. Thamatrakoln (2021), Impaired viral infection and reduced mortality of diatoms in iron-limited oceanic regions, Nature Geoscience, 14, 231-237, doi:10.1038/s41561-021-00711-6.
19. Boyle, E.A., C. Zurbrick, J.-M. Lee, R. Till, C.P. Till, J. Zhang, A.R. Flegal (2020), Lead and lead isotopes in the U.S. GEOTRACES East Pacific zonal transect (GEOTRACES GP16), Marine Chemistry, 227, doi:10.1016/j.marchem.2020.103892.
18. Ruacho, A., R.M. Bundy, C.P. Till, S. Roshan, J. Wu and K.A. Barbeau (2020), Organic dissolved copper speciation across the U.S. GEOTRACES Equatorial Pacific Zonal Transect GP16, Marine Chemistry, 225, doi:10.1016/j.marchem.2020.103841.
17. Kadko, D., A. Aguilar-Islas, C.S. Buck, J.N. Fitzsimmons, W.M. Landing, A. Shiller, C.P. Till, K.W. Bruland, E.A. Boyle and R.F. Anderson (2020), Sources, fluxes and residence times of trace elements measured during the U.S. GEOTRACES East Pacific Zonal Transect, Marine Chemistry, 222, doi:10.1016/j.marchem.2020.103781.
16. Sprowles, A., K. Goldenberg, P.D. Goley, S. Ladwig, F. Shaughnessy, K.J. Malloy, C.R. Baldy, M.M. Mola, J.R. Smith, M.A. Hemphill-Haley, M.J. Michalak, C.P. Till, A.P. O’Dowd, G. Black, P.L. Siering, E. Cashman, A.M.F. Tomescu, M.P. Hurst, B. Mazzag, S. Manor, D.R. Oliver, J.R. Dunk, J. Abel, M.S. Gunther, A. Buchheister, R. Saunders, J. Floss, E. Sullivan, S. Ben-Zvi, and M.D. Johnson (2019), Place-Based Learning Communities on a Rural Campus: Turning Challenges into Assets, Learning Communities Research and Practice, 7(1), Article 6.
15. Till C.P., J.R. Solomon*, N.R. Cohen, R.H. Lampe, A. Marchetti, T.H. Coale, and K.W. Bruland (2019), The iron limitation mosaic in the California Current System: factors governing Fe availability, Limnology and Oceanography, 64(1), 109-123, doi:10.1002/lno.11022.
14. Boiteau, R.M., C.P. Till, T.H. Coale, J.N. Fitzsimmons, K.W. Bruland, D.J. Repeta (2019), Patterns of iron and siderophore distributions across the California Current System, Limnology and Oceanography, 64(1), 376-389, doi:10.1002/lno.11046.
13. Lampe, R.H., E. L. Mann, N. R. Cohen, C.P. Till, K. Thamatrakoln, M. A. Brzezinski, K.W. Bruland, B.S. Twining, and A. Marchetti (2018), Different iron storage strategies among bloom-forming diatoms, Proceedings of the National Academy of Sciences, doi:10.1073/pnas.1805243115.
12. Lampe R.H., N.R. Cohen, K.A. Ellis, K.W. Bruland, M.T. Maldonado, T.D. Peterson, C.P. Till, M.A. Brzezinski, S. Bargu, K. Thamatrakoln, F.I. Kuzminov, B.S. Twining, and A. Marchetti (2018), Divergent gene expression among phytoplankton taxa in response to upwelling, Environmental Microbiology, 20(8), 3069-3082, doi:10.1111/1462-2920.14361.
11. Schlitzer, R., et al. (2018), The GEOTRACES Intermediate Data Product 2017, Chemical Geology, 493, 210-223, doi:10.1016/j.chemgeo.2018.05.040.
10. Coale, K.H., W.A. Heim, J. Negrey, P. Weiss-Penzias, D. Fernandez, A. Olson, H. Chiswell, A. Byington, A. Bonnema, S. Martenuk, A. Newman, C. Beebe, C.P. Till (2018), The distribution and speciation of mercury in the California current: Implications for mercury transport via fog to land, Deep-Sea Research Part II, 151, 77-88, doi:10.1016/j.dsr2.2018.05.012.
9. McNair, H.M., M.A. Brzezinski, C.P. Till, J.W. Krause (2018), Taxon-specific contributions to silica production in natural diatom assemblages, Limnology and Oceanography, 63, 1056-1075, doi:10.1002/lno.10754.
8. John, S.G., J. Helgoe, E. Townsend, T. Weber, T. DeVries, A. Tagliabue, K. Moore, P. Lam, C.M. Marsay, and C.P. Till (2018), Biogeochemical cycling of Fe and Fe stable isotopes in the Eastern Tropical South Pacific, Marine Chemistry, doi:10.1016/j.marchem.2017.06.003.
7. Mellett, T., M.T. Brown, P.D. Chappell, C. Duckham, J.N. Fitzsimmons, C.P. Till, R.M. Sherrell, M.T. Maldonado, K.N. Buck (2018), The biogeochemical cycling of iron, copper, nickel, cadmium, manganese, cobalt, lead, and scandium in a California Current experimental study, Limnology and Oceanography, 63, S425-S447, doi:10.1002/lno.10751.
6. Cohen, N.R., K.A. Ellis, R.H. Lampe, H. McNair, B.S. Twining, M.T. Maldonado, M.A. Brzezinski, F.I. Kuzminov, K. Thamatrakoln, C.P. Till, K.W. Bruland, W.G. Sunda, S. Bargu and A. Marchetti (2017) Diatom Transcriptional and Physiological Responses to Changes in Iron Bioavailability across Ocean Provinces, Frontiers in Marine Science, 4:360, doi:10.3389/fmars.2017.00360.
5. Hein, J.R., N. Konstantinova, M. Mikesell, K. Mizell, J.N. Fitzsimmons, P.J. Lam, L.T. Jensen, Y. Xiang, A. Gartman, G. Cherkashov, D.R. Hutchinson, C.P. Till (2017). Arctic deep water ferromanganese-oxide deposits reflect the unique characteristics of the Arctic Ocean, Geochemistry, Geophysics, Geosystems, 18, doi:10.1002/2017GC007186.
4. Till, C.P., R.U. Shelley, W.M. Landing, and K.W. Bruland (2017), Dissolved scandium, yttrium, and lanthanum in the surface waters of the North Atlantic: Potential use as an indicator of scavenging intensity, Journal of Geophysical Research: Oceans, 122, doi:10.1002/2017JC012696.
3. Heller, M.I., P.J. Lam, J.W. Moffett, C.P. Till, J.-M. Lee, B.M. Toner, and M.A. Marcus (2017), Accumulation of Fe oxyhydroxides in the Peruvian oxygen deficient zone implies non-oxygen dependent Fe oxidation, Geochimica et Cosmochimica Acta, 211, 174-193, doi:10.1016/j.gca.2017.05.019.
2. Boiteau, R.M., C.P. Till, A. Ruacho, R.M. Bundy, N.J. Hawco, A.M. McKenna, K.A. Barbeau, K.W. Bruland, M.A. Saito, and D.J. Repeta (2016), Structural Characterization of Natural Nickel and Copper Binding Ligands along the US GEOTRACES Eastern Pacific Zonal Transect, Frontiers in Marine Science, 3, 243, doi:10.3389/fmars.2016.00243.
1. Parker, C.E., M.T. Brown, and K.W. Bruland (2016), Scandium in the open ocean: A comparison with other group 3 trivalent metals, Geophysical Research Letters, 43, 2758–2764, doi:10.1002/2016GL067827.
