Postdoctoral scholar, Marine Chemistry & Geochemistry, Woods Hole Oceanographic Institution, 2005-2007

Ph.D., Oceanography (chemical), University of Connecticut, 2005

M.S., Biology, University of Wisconsin-La Crosse, 1999

B.S., Biology/Aquatic Sciences, University of Wisconsin-La Crosse, 1997

Diploma, Fairmont (Minnesota) High School, 1993

Fall Semester

• EES 1990 EES First-Year Seminar, 1 credit hr
• EES 4240/6240 Oceanography, 3 credit hrs
• EES 4010/6010 Quality Assurance of Environmental Analysis, 0.5 credit hr

Spring Semester

• EES 4590/6590 Aquatic Geochemistry, 3 credit hrs [Odd Years]
• EES 4510/6510 Scientific Communication, 3 credit hrs [Even Years]

Summer Semester

• EES 4600/6601 Limnology, 3 credit hrs

Methylmercury is the form of mercury (Hg) that bioaccumulates and biomagnifies in food webs, especially piscivorous fish, and represents the primary human health concern related to Hg in the environment.  Most fish consumed by humans are of marine origin. Unfortunately, little is known about the sources and cycling of methylmercury in marine systems. Our prior and ongoing research is focused on Hg and methylmercury cyling in coastal marine and open-ocean systems. This research has been supported mostly by the U.S. National Science Foundation, in part related to the U.S. GEOTRACES program. We have participated in the North Atlantic, equatorial South Pacific, and Arctic Ocean U.S. GEOTRACES sections, and received water and particles for Hg speciation analysis from the recent Pacific Ocean meridional section.

Other on-going research topics in Hammerschmidt's lab include investigations of, for example, 1) phosphorus and trace metal cycling and fluxes in Ohio rivers and lakes, 2) lead (Pb) in drinking water of southwest Ohio, 3) Hg speciation and fluxes in meltwater from Alaskan glaciers, 4) Hg cycling in Gulf of Mexico estuaries, 5) Hg methylation in seawater, and 6) methylmercury bioaccumulation in sharks and bathypelagic fishes. All of these research projects include collaboration with international experts. 

Other ongoing student projects:

• Lead in Dayton tap water
• Mercury in south Florida shark bio-reservoirs
• Mercury mobilization from soil as a result of land use changes
• Environmental factors affecting concentrations of methylmercury in fish of the Laurentian Great Lakes region
• Methylmercury bioaccumulation in mesopelagic fish of the northern Gulf of Mexico
• Mercury and trace metal distributions in sediment on the New England continental margin
• Selenium amelioration of methylmercury toxicity in freshwater fish

Dr. Hammerschmidt is currently advising research of multiple students (expected year of graduation):

• Emily L. Holliday, M.S. student (2021)
• Paul J. Fleischman, M.S. student (2021)
• Ashley N. Livingston, M.S. student (2021)
• Lindsay D. Starr, Ph.D. student (2021)
• Marissa Despins, M.S. student (2022)

 

Student Theses and Dissertations

• Lisa M. Romas, M.S., 2010. Functional identification of microorganisms that transform mercury in marine sediments. (Now, employed at NJ DEP)
• Melissa D. Tabatchnick, M.S., 2010.  Mercury speciation in temperate tree foliage. (Now, student in physical therapy school in RI)
• Avani P. Naik, M.S., 2010. Trace metal fluxes in southwest Ohio watersheds. (Now, environmental consultant in PA)
• Katlin L. Bowman, B.S., 2010. Decomposition of methylmercury in seawater. (Now, postdoc at Univ. California Santa Cruz)
• Robbie L. Weller, B.S., 2011. Methylmercury in zooplankton on the continental margin of the northwest Atlantic Ocean.  (Now, veterinarian in OH)
• Matthew J. Konkler, M.S., 2011. Methylmercury in mosquitoes: Impact of a large coal-fired power station in central Ohio. (Now, research assistant at Oregon State Univ.)
• Astrea Taylor, M.S., 2012.  Fluxes of phosphorus to Grand Lake St. Mary’s. (Now, at Ohio EPA)
• Jaclyn E. Klaus, B.S., 2012. Functional identification of mercury transforming microorganisms in freshwater sediments. (Now, Michigan DNR)
• Deepthi Nalluri, B.S., 2013. Methylmercury in dried shark fins and shark fin soup from American restaurants. (Currently, M.D. student at Boonshoft School of Medicine)
• Daniel L. Marsh, M.S., 2013. Trace metals in sediments on the continental margin of the northwest Atlantic Ocean. (Now, Corp. account manager for ChemTreat)
• Kelsey M. Danner, M.S., 2013. Copper and nickel partitioning with nanoscale goethite. (Now, Ph.D. student at Ohio State)
• Rebecca L. Gamby, M.S., 2014. Effect of deforestation and cultivation on mercury in soil. (Now, high school science teacher in OH)
• Jaclyn E. Klaus, M.S., 2014. Net methylmercury production in two contrasting stream sediments and association accumulation and toxicity to periphyton. (now, nursing student)
• Sarah E. Harvey, M.S., 2014. Stability of methylmercury in water. (Now, at Ohio EPA)
• Katlin Bowman, Ph.D., 2014.  Mercury distributions and cycling in the North Atlantic and eastern tropical South Pacific Oceans. (Postdoc at UC Santa Cruz)
• Heather B. Perusini, M.S., 2016. Temporal variation of mercury in effluent from two municipal wastewater treatment plants in southwest Ohio.
• Katelynn L. Alcorn, B.S., 2016.  Methylmercury accumulation in meso- and bathypelagic fish of the northern Gulf of Mexico. (Now, M.D. student at Boonshoft School of Medicine)
• Kelly M. Muterspaw, B.S., 2017. Methylmercury accumulation in meso- and bathypelagic fish of the northern Gulf of Mexico. (Now, M.D. student at Boonshoft School of Medicine)
• Rachel A. Walker, M.S., 2017. Methylmercury accumulation in spotted salamanders of southern Ohio. (Now, QC officer at Volvo paint division, Blacksburg, VA)
• Dane C. Boring, M.S., 2017. Effect of land use on mercury in topsoils. (Now, Kansas Department of Health & Environment)
• Kortney R. Mullen, M.S., 2017. Benthic phosphorus fluxes in the Lower Great Miami River. (Now, Suez Water Technologies)
• Kayla M. Haman, M.S., 2018. Lead in tap water from the City of Dayton, Ohio (Now, Civil & Environmental Consultants, Inc., OH)
• Alison M. Agather, Ph.D., 2018. Distribution of mercury species in the western Arctic Ocean (Now, program coordinator NOAA Weather Program Office)
• Baylee Stark, M.S., 2019. Lead in tap water of public schools near Dayton, Ohio (Now, Ohio EPA Air)

Hammerschmidt's WSU student coauthors are in bold text:

84. Charette, M. A., L. E. Kipp, L. Jensen, J. S. Dabrowski, L. M. Whitmore, J. Fitzsimmons, T. Molodtsova, A. Ulfsbo, E. Jones, R. M. Bundy, S. M. Vivancos, K. Pahnke, S. John, Y. Xiang, M. Hatta, M. V. Petrova, L.-E. Heimbürger-Boavida, D. Bauch, R. Newton, A. Pasqualini, A. M. Agather, R. F. Anderson, P. S. Andersson, R. M. W. Amon, R. Benner, K. L. Bowman, L. Edwards, S. Gdaniec, A. G. González, M. Granskog, B. Haley, C. R. Hammerschmidt, D. A. Hansell, P. Hendersen, K. Kaiser, P. J. Lam, C. H. Lamborg, M. Levier, X. Li, A. R. Margolin, C. Measures, F. J. Millero, W. S. Moore, R. Paffrath, H. Panquette, B. Rabe, H. Reader, R. Rember, M. Roy-Barman, M. R. van der Loeff, M. Saito, U. Schauer, P. Schlosser, R. Sherrell, A. Shiller, H. Slagter, J. E. Sonke, C. Stedmon, R. J. Woosley, O. Valk, R. Zhang (2020) The transpolar drift as a source of riverine and shelf-derived trace elements to the Central Arctic Ocean. Journal of Geophysical Research-Oceans 125, e2019JC015920

83.Mullen, K. R., C. R. Hammerschmidt, M. Ekberg, M. J. McCarthy, S. E. Newell, A. M. Agather (2020) External sources inhibit benthic phosphorus fluxes in the Lower Great Miami River, southwest Ohio. Environmental Toxicology & Chemistry 39, 1517–1525.

82.Gustin, M. S., M. Bank, K. Bishop, K. Bowman, B. Branfireun, J. Chetelat, C. Eckley, C. Hammerschmidt, C. Lamborg, S. Lyman, A. M. Cortiazas, J. Sommar, M. Tsui, T. Zhang. (2020) Mercury biogeochemical cycling: A synthesis of recent scientific advances. Science of the Total Environment 737, 139619.

81. Perusini, H. B., C. R. Hammerschmidt (2020) Temporal variation of mercury in effluent from two municipal wastewater treatment plants in southwest Ohio. Environmental Toxicology & Chemistry 39, 1027-1031.

80. Bowman, K. L., E. R. Collins, A. M. Agather, C. H. Lamborg, C. R. Hammerschmidt, D. Kaul, C. Dupont, C. Christensen, D. G. Elias (2020) Distribution of mercury-cycling genes in the Arctic and Equatorial Pacific Oceans and their relationship to mercury speciation. Limnology & Oceanography 65, S310-S320.

79. Nogaro, G., A. J. Burgin, A.Taylor, C. R. Hammerschmidt (2019) Alum treatment did not improve water quality in hypereutrophic Grand Lake St. Mary's, Ohio. In Internal Phosphorus Loading in Lakes: Causes, Case Studies, and Management (A. D. Steinman, B. M. Spears, eds.).

78. Costello, D. M., A. M. Harrison, C. R. Hammerschmidt, R. M. Mendonca, G. A. Burton, Jr. (2019) Hitting reset on sediment toxicity: sediment homogenization alters the toxicity of metal-amended sediments. Environmental Toxicology & Chemistry 38, 1995-2007.

77. Agather, A. M., K. L. Bowman, C. H. Lamborh, C. R. Hammerschmidt (2019) Distribution of mercury species in the Western Arctic Ocean (U.S. GEOTRACES GN01). Marine Chemistry 216, 103686.

76. Schlitzer, R. et al. (2018) The GEOTRACES Intermediate Data Product 2017. Chemical Geology 493, 210-223.

75. Fitzgerald, W. F., D. R. Engstrom, C. R. Hammerschmidt, C H. Lamborg, P. H. Balcom, A. S. Lima-Braun, M. H. Bothner, C. M. Reddy (2018) Global and local sources of mercury deposition in coastal New England reconstructed from a multiproxy, high-resolution, estuarine sediment record. Environmental Science & Technlogy 52, 7614–7620.

74. Slone, L. A., M. J. McCarthy, J. A. Myers, C. R. Hammerschmidt, S. E. Newell (2018) River sedimment nitrogen removal and recycling within an agricultural Midwestern USA watershed. Freshwater Science 37, 1–12.

73. Blum, P. W., A. E. Hershey, M. T.-K. Tsui, C. R. Hammerschmidt, A. M. Agather (2017) Methylmercury and methane production potentials in North Carolina Piedmont stream sediments. Biogeochemistry 137, 181–195.

72. Matulik, A. G., D. W. Kersetter, N Hammerschlag, T. Divoll, C. R. Hammerschmidt, D. C. Evers (2017) Bioaccumulation and biomagnification of mercury and methylmercury in four sympatric coastal sharks in a protected subtropical lagoon. Marine Pollution Bulletin 116, 357–364.

71. Mason, R. P., C. R. Hammerschmidt, C. H. Lamborg, K. L. Bowman, G. J. Swarr, R. U. Shelley (2017) The air-sea exchange of mercury in the low latitude Pacific and Atlantic Oceans. Deep-Sea Research I 122, 17–28.

70. Lamborg, C. H., C. R. Hammerschmidt, K. L. Bowman (2016) An examination of the role of particles in oceanic mercury cycling. Philosophical Transactions of the Royal Society A doi: 10.1098/rsta.2015.0297.

69. Bowman, K. L., C. R. Hammerschmidt, C. H. Lamborg, G. J. Swarr, A. M. Agather (2016) Distribution of mercury species across a zonal section of the eastern tropical South Pacific Ocean (U.S. GEOTRACES GP16). Marine Chemistry 186, 156-166.

68. Swarr, G. J., T. Kading, C. H. Lamborg, C. R. Hammerschmidt, K. L. Bowman (2016) Dissolved low-molecular weight thiol concentrations from the U.S. GEOTRACES North Atlantic Ocean zonal transect. Deep-Sea Research I 116, 77-87.

67. Costello, D. M., C. R. Hammerschmidt, G. A. Burton (2016) Nickel partitioning and toxicity in sediment during aging: Variation in toxicity related to stability of metal partitioning. Environmental Science & Technology 50, 11337-11345.

66. Gustin, M. S., D. C. Evers, M. S. Bank, C. R. Hammerschmidt, A. Pierce, N. Basu, J. Blum, P. Bustamante, C. Chen, C. T. Driscoll, M. Horvat, D. Jaffe, J. Pacyna, N. Pirrone, M. Selin. (2016) Importance of integration and implementation of emerging and future research into the Minamata Convention.  Environmental Science & Technology 50, 2767–2770.

65. Fetters, K. J., D. M. Costello, C. R. Hammerschmidt, G. A. Burton (2016)  Toxicological effects of short-term resuspension of metal contaminated freshwater and marine sediments. Environmental Toxicology and Chemistry 35, 676-686.

64. Klaus, J. E., C. R. Hammerschmidt, D. M. Costello, G. A. Burton Jr. (2016) Net methylmercury production in two contrasting stream sediments and associated accumulation and toxicity to periphyton. Environmental Toxicology & Chemistry 35, 1759-1765.

63. Custer, K. W., C. R. Hammerschmidt, G. A. Burton, (2016) Nickel toxicity to benthic organisms: The role of dissolved organic carbon, suspended solids, and route of exposure. Environmental Pollution 208, 309–317.

62, Evans, D. W., M. Cohen, C. Hammerschmidt, W. Landing, D. Rumbold, J. Simons, S. Wolfe (2015) White paper on Gulf of Mexico mercury fate and transport: applying scientific research to reduce the risk of mercury in Gulf of Mexico seafood. NOAA Technical Memorandum NOS NCCOS 192, 54 pp. 

61. Buck, C. S., C. R. Hammerschmidt, K. L. Bowman, G. A. Gill, W. M. Landing (2015)  Flux of total and methyl mercury to the northern Gulf of Mexico from U.S. estuaries. Environmental Science & Technology 49, 13992–13999.

60. Gamby, R. L., C. R. Hammerschmidt, D. M. Costello, C. H. Lamborg, J. R. Runkle (2015)  Deforestation and cultivation mobilize mercury from topsoil. Science of the Total Environment 532, 467–473. 

59. Costello, D. M., C. R. Hammerschmidt, G. A. Burton (2015) Copper sediment toxicity and partitioning during oxidation in a flow-through flume. Environmental Science & Technology 49, 6926–6933.

58. Walters, D. M., D. F. Raikow, C. R. Hammerschmidt, M. G. Mehling, A. Kovatch, J. T. Oris (2015)  Primary productivity reduces methylmercury bioaccumulation and trophic transfer in experimental stream food webs.  Environmental Science & Technology 49, 7762–7769.

57. Danner, K. M., C. R. Hammerschmidt, D. M. Costello, G. A. Burton (2015) Copper and nickel partitioning with nanoscale goethite under variable aquatic conditions.  Environmental Toxicology & Chemistry 34, 1705–1710.

56. Bowman, K. L., C. R. Hammerschmidt, C. H. Lamborg, G. S. Swarr. (2015)  Mercury in the North Atlantic Ocean: The U.S. GEOTRACES zonal and meridional sections. Deep-Sea Research II 116, 251–261. 

55. Hammerschmidt, C. R., M. S. Gustin, J. Bennett. (2014) Mercury biogeochemical cycling and processes: implications for human and ecosystem health. Science of the Total Environment 496, 635.

54. Nalluri, D., Z. Baumann, D. L. Abercrombie, D. D. Chapman, C. R. Hammerschmidt, N. S. Fisher (2014) Methylmercury in dried shark fins and shark fin soup from American restaurants. Science of the Total Environment 469, 644–648.  

53. Lamborg, C. H., C. R. Hammerschmidt, K. L. Bowman, G. S. Swarr, K. M. Munson, D. C. Ohnemus, P. J. Lam, L-E. Heimbürger, M. J. A. Rijkenberg, M. A. Saito (2014) A global ocean inventory of anthropogenic mercury based on water column measurements. Nature 512, 65–68.

52. Fitzgerald, W. F., C. R. Hammerschmidt, D. R. Engstrom, P. H. Balcom, C. H. Lamborg, C.-M. Tseng (2014)  Mercury in the Alaskan Arctic.  In Alaska’s Changing Arctic: Ecological Consequences for Tundra, Streams and Lakes, J. E. Hobbie and G. W. Kling (Eds.), Oxford University Press, New York. pp. 287–302.

51. Lamborg, C. H., K. L. Bowman, C. R. Hammerschmidt, C. C. Gilmour, K. Munson, N. Selin, C.-M. Tseng (2014)  Mercury in the anthropocene ocean. Oceanography 27, 76–87. 

50. Barst, B. D., C. R. Hammerschmidt, M. M. Chumchal, D. C. G. Muir, J. D. Smith, A. P. Roberts, T. R. Rainwater, P. E. Drevnick (2013) Determination of mercury speciation in fish tissue with a direct mercury analyzer.  Environmental Toxicology & Chemistry 32, 1237–1241. 

49. Blank, N., A. G. Hudson,  P. Vonlanthen, A. Hudson, O. Seehausen, C. R. Hammerschmidt, D. B. Senn  (2013) Speciation leads to divergent methylmercury accumulation in sympatric whitefish in Swiss lakes.  Aquatic Sciences 75, 261–273. 

48. Hammerschmidt, C. R., M. Finiguerra, R. L. Weller, W. F. Fitzgerald (2013) Methylmercury accumulation in plankton on the continental margin of the northwest Atlantic Ocean. Environmental Science & Technology 47, 3671–3677. 

47. Nogaro, G., A. J. Burgin, V. Schoepfer, M. J. Konkler, K. L. Bowman, C. R. Hammerschmidt  (2013) Aluminum sulfate (alum) application interactions with coupled metal and nutrient cycling in a hypereutrophic lake ecosystem. Environmental Pollution 176, 267–274. 

46. Nogaro, G., C. R. Hammerschmidt  (2013)  Influence of macrofauna on microbial production of methylmercury in sediments on the New England continental shelf.  Hydrobiologia 701, 289–299.

45. Driscoll, C. T., C. Y. Chen, C. R. Hammerschmidt, R. P. Mason, C. C. Gilmour, E. M. Sunderland, B. K. Greenfield, K. L. Buckman, C. H. Lamborg (2012) Nutrient supply and mercury dynamics in coastal ecosystems: a conceptual model. Environmental Research 119, 118–131. 

44. Mason, R. P., A. L. Choi, W. F. Fitzgerald, C. R. Hammerschmidt, C. H. Lamborg, E. M. Sunderland (2012) Mercury biogeochemical cycling in the ocean and policy implications.  Environmental Research 119, 101–117. 

43. Costello, D. M., G. A. Burton, C. R. Hammerschmidt, W. K. Taulbee  (2012)  Evaluating the performance of passive sampling devices (DGTs) for predicting nickel sediment toxicity.  Environmental Science & Technology 46, 10239–10246. 

42. Depew, D. C., N. Basu, N. M. Burgess, L. M. Campbell, E. W. Devlin, P. E. Drevnick, C. R. Hammerschmidt, C. A. Murphy, M. B. Sandheinrich, J. G. Wiener (2012) Toxicity of dietary methylmercury to fish: derivation of ecologically meaningful threshold concentrations. Environmental Toxicology & Chemistry 31, 1536–1547.

41. Konkler, M. J., C. R. Hammerschmidt (2012) Methylmercury in mosquitoes: Impact of a large coal-fired power plant in central Ohio. Environmental Toxicology & Chemistry 31, 1657–1661. 

40. Hammerschmidt, C. R., K. L. Bowman  (2012)  Vertical methylmercury distribution in the subtropical North Pacific.  Marine Chemistry  132–133, 77–82. http://www.sciencedirect.com/science/article/pii/S0304420312000242

39. Lamborg, C. H., C. R. Hammerschmidt, G. A. Gill, R. P. Mason , S. Guchuki (2012)  An intercomparison of methods and protocol development for Hg speciation in open ocean seawater suitable for use on GEOTRACES cruises. Limnology & Oceanography: Methods 10, 90–100.

38. Tabatchnick, M. D., G. Nogaro, C. R. Hammerschmidt  (2012)  Potential sources of methylmercury in tree foliage. Environmental Pollution 160, 82–87.

37. Hammerschmidt, C. R.  (2011) Mercury and carbon dioxide emissions: uncoupling a toxic relationship. Environmental Toxicology & Chemistry 30, 2640−2646.

36. Hammerschmidt, C. R., K. L. Bowman, M. D. Tabatchnick, C. H. Lamborg (2011) Storage bottle material and cleaning for determination of total mercury in seawater. Limnology & Oceanography: Methods  9, 426–431. 

35. Naik, A. P., C. R. Hammerschmidt  (2011)  Mercury and trace metal partitioning and fluxes in suburban southwest Ohio watersheds.  Water Research  45, 5151–5160. 

34. Costello, D. M., G. A. Burton, Jr., C. R. Hammerschmidt, E. Rogevich, C. Schlekat (2011) Nickel phase partitioning and toxicity in field-deployed sediments.  Environmental Science & Technology  45, 5798–5805.

33. Brumbaugh, W. G., C. R. Hammerschmidt, L. Zanella, E. Rogevich, G. Salata, R. Bolek  (2011)  Inter-laboratory comparison of measurements of acid-volatile sulfide and simultaneously extracted nickel in spiked sediments.  Environmental Toxicology & Chemistry 30,1306–1309.

32. Bowman, K. L., C. R. Hammerschmidt  (2011)  Extraction of monomethylmercury from seawater for low-femtomolar determination.  Limnology & Oceanography: Methods 9, 121–128. 

31. Bowling, A. M., C. R. Hammerschmidt, J. T. Oris (2011)  Necrophagy by a benthic omnivore influences biomagnification of methylmercury in fish.  Aquatic Toxicology  102, 134–141. 

30. Hammerschmidt, C. R., W. F. Fitzgerald (2010) Iron-mediated photochemical decomposition of methylmercury in an arctic Alaskan lake.  Environmental Science & Technology  44, 6138–6143.  

29. Cloran, C. E., G. A. Burton, Jr., C. R. Hammerschmidt, K. W. Taulbee, K. Custer, K. L. Bowman (2010) Effects of suspended solids and dissolved organic carbon on nickel toxicity.  Environmental Toxicology & Chemistry 29, 1781–1787. 

28. Hammerschmidt, C. R., G. A. Burton, Jr. (2010) Measurements of acid volatile sulfide and simultaneously extracted metals are irreproducible among laboratories.  Environmental Toxicology & Chemistry  29, 1453–1456. 

27. Evers, D.C., R.P. Mason, N.C. Kamman, C.Y. Chen, A.L. Bogomolni, D.L. Taylor, C.R. Hammerschmidt, S.H. Jones, N.M. Burgess, K. Munney, K.C. Parsons (2008) Integrated mercury monitoring program for temperate estuarine and marine ecosystems on the North American Atlantic coast. EcoHealth 5, 426–441.

26. Lamborg, C. H., O. Yigiterhan, W. F. Fitzgerald, P. H. Balcom, C. R. Hammerschmidt, J. Murray (2008) Vertical distribution of mercury species at two sites in the western Black Sea. Marine Chemistry 111, 77–89.

25. Hammerschmidt, C. R., W. F. Fitzgerald (2008) Methylmercury in arctic Alaskan mosquitoes: Implications for impact of atmospheric mercury depletion events. Environmental Chemistry 5, 127−130.

24. Drevnick, P. E., A. P. Roberts, R. R. Otter, C. R. Hammerschmidt, R. Klaper, J. T. Oris. (2008) Mercury toxicity in livers of northern pike (Esox lucius) from Isle Royale, USA. Comparative Biochemistry and Physiology-Part C 147, 331-338. 

23. Rolfhus, K. R., M. B. Sandheinrich, J. G. Wiener, S. W. Bailey, K. A. Thoreson, C. R. Hammerschmidt (2008) Analysis of fin clips as a non-lethal method for monitoring mercury in fish. Environmental Science & Technology 42, 871−877. 

22. Balcom, P. H., C. R. Hammerschmidt, W. F. Fitzgerald, C. H. Lamborg, J. S. O’Connor (2008) Seasonal distributions and cycling of mercury and methylmercury in the waters of New York/New Jersey Harbor Estuary. Marine Chemistry 109, 1−17.

21. Hammerschmidt, C. R., W. F. Fitzgerald (2008) Sediment-water exchange of methylmercury determined from shipboard benthic flux chambers. Marine Chemistry 109, 86−97.

20. Hammerschmidt, C. R., W. F. Fitzgerald, P. H. Balcom, P. T. Visscher (2008) Organic matter and sulfide inhibit methylmercury production in sediments of New York/New Jersey Harbor. Marine Chemistry 109, 165−182.

19. Hammerschmidt, C. R., C. H. Lamborg, W. F. Fitzgerald (2007) Aqueous phase methylation as a potential source of methylmercury in wet deposition. Atmospheric Environment 41, 1663-1668.

18. Fitzgerald, W. F., C. H. Lamborg, C. R. Hammerschmidt (2007) Marine biogeochemical cycling of mercury. Chemical Reviews 107, 641-662.

17. Hammerschmidt, C. R., W. F. Fitzgerald (2006) Methylmercury in freshwater fish linked to atmospheric mercury deposition. Environmental Science & Technology 40, 7764–7770.

16. Hammerschmidt, C. R., W. F. Fitzgerald (2006) Bioaccumulation and trophic transfer of methylmercury in Long Island Sound. Archives of Environmental Contamination & Toxicology 51, 416-424.

15. Lamborg, C. H., K. L. Von Damm, W. F. Fitzgerald, C. R. Hammerschmidt, R. Zierenberg (2006) Mercury and monomethylmercury in fluids from Sea Cliff submarine hydrothermal field, Gorda Ridge. Geophysical Research Letters 33, L17606. 

14. Hammerschmidt, C. R., W. F. Fitzgerald, C. H. Lamborg, P. H. Balcom, C.-M. Tseng (2006) Biogeochemical cycling of methylmercury in lakes and tundra watersheds of arctic Alaska. Environmental Science & Technology 40, 1204-1211. 

13. Hammerschmidt, C. R., W. F. Fitzgerald (2006) Photodecomposition of methylmercury in an arctic Alaskan lake. Environmental Science & Technology 40, 1212-1216.

12. Hammerschmidt, C. R., W. F. Fitzgerald (2006) Methylmercury cycling in sediments on the continental shelf of southern New England. Geochimica et Cosmochimica Acta 70, 918-930.

11. Hammerschmidt, C. R., M. B. Sandheinrich (2005) Maternal diet during oogenesis is the major source of methylmercury in fish embryos. Environmental Science & Technology 39, . 3580-3584.

10. Hammerschmidt, C. R., W. F. Fitzgerald (2005) Methylmercury in mosquitoes related to atmospheric mercury deposition and contamination. Environmental Science & Technology 39, 3034-3039.

9. Fitzgerald, W. F., D. R. Engstrom, C. H. Lamborg, C.-M. Tseng, P. H. Balcom, C. R. Hammerschmidt (2005) Modern and historic atmospheric mercury fluxes in northern Alaska: Global sources and arctic depletion. Environmental Science & Technology 39, 557-568. 

8. Tseng, C.-M., C. R. Hammerschmidt, W. F. Fitzgerald (2004) Determination of methylmercury in environmental matrixes by on-line flow injection and atomic fluorescence spectrometry. Analytical Chemistry 76, 7131-7136.

7. Hammerschmidt, C. R., W. F. Fitzgerald, C. H. Lamborg, P. H. Balcom, P. T. Visscher (2004) Biogeochemistry of methylmercury in sediments of Long Island Sound. Marine Chemistry 90, 31-52.

6. Balcom, P. H., W. F. Fitzgerald, G. M. Vandal, C. H. Lamborg, C. S. Langer, K. R. Rolfhus, C. R. Hammerschmidt (2004) Mercury sources and cycling in the Connecticut River and Long Island Sound. Marine Chemistry 90, 53-74. 

5. Hammerschmidt, C. R., W. F. Fitzgerald (2004) Geochemical controls on the production and distribution of methylmercury in near-shore marine sediments. Environmental Science & Technology 38, 1487-1495.

4. Lamborg, C. H., C.-M. Tseng, W. F. Fitzgerald, P. H. Balcom, C. R. Hammerschmidt (2003) Determination of the mercury complexation characteristics of dissolved organic matter in natural waters with “reducible Hg” titrations. Environmental Science & Technology 37, 3316-3322. 

3. Hammerschmidt, C. R., M. B. Sandheinrich, J. G. Wiener, R. G. Rada (2002) Effects of dietary methylmercury on reproduction of fathead minnows. Environmental Science & Technology 36, 877-883.

2. Hammerschmidt, C. R., W. F. Fitzgerald (2001) Formation of artifact methylmercury during extraction from a sediment reference material. Analytical Chemistry 73, 5930-5936.

1. Hammerschmidt, C. R., J. G. Wiener, B. E. Frazier, R. G. Rada (1999) Methylmercury content of eggs in yellow perch related to maternal exposure in four Wisconsin lakes. Environmental Science & Technology 33, 999-1003.

I am a member of the following professional societies:

• American Chemical Society, 2002–present
• Association for the Sciences of Limnology & Oceanography, 2010–present
• American Geophysical Union, 2006–present
• Society of Environmental Toxicology & Chemistry, 1997–present

• Exceptional Paper Award, Environmental Toxicology & Chemistry for Costello et al., 2019
• Exceptional peer-reviewer award for Environmental Toxicology & Chemistry in 2017, 2018
• Student’s Choice Award for Outstanding Teaching in College of Science and Mathematics, Wright State University, 2015−2016
• 2008 Rada Distinguished Alumni Award, University of Wisconsin-La Crosse
• Invited participant, Dissertations Symposium on Chemical Oceanography (DISCO) XIX, 2005
• Graduate Student Fellowship, Hudson River Foundation for Environmental Research, 2004-2005
• STAR Graduate Student Fellowship, U.S. Environmental Protection Agency, 2001-2004
• Senior of the Year, Department of Biology & Microbiology, University of Wisconsin-La Crosse, 1997