Deborah Bronk, PhD

President and CEO
Senior Research Scientist
Phone: +1 (207) 315-2567, ext. 115

For media inquiries, please contact

Deborah Bronk joined Bigelow Laboratory in February 2018 as its president and CEO.

She earned a Ph.D. in marine-estuarine and environmental sciences from the University of Maryland, and she has more than two decades of experience as a professor and an oceanographer. During that time, she has conducted more than 50 research cruises and field studies in freshwater and marine environments that stretch from pole to pole.

Dr. Bronk also serves as president of The Oceanography Society and chairs the UNOLS Council, the University-National Oceanographic Laboratory System. In 2020, she was recognized as a Fellow of the American Association for the Advancement of Science, for her substantial research advances on the marine nitrogen cycle and for her leadership in the ocean science research community.

Previously, Dr. Bronk was the Moses D. Nunnally Distinguished Professor of Marine Studies and department chair at Virginia Institute of Marine Science within the College of William & Mary. She also served as division director for the National Science Foundation’s Division of Ocean Science and as president of the Association for the Sciences of Limnology and Oceanography.


Ph.D., Marine Estuarine and Environmental Sciences, Horn Point Laboratory, University of Maryland, College Park, MD, June 1992.

B.S., Biology and Marine Science, University of Miami, Miami, FL, May 1986.

Research Interests

My research is all about NITROGEN! I am interested in ways that nitrogen controls the growth of the microscopic organisms at the base of the food web in open-ocean, coastal, and estuarine environments. My early work involved extensive method development with the goal of finding ways to measure how quickly phytoplankton and bacteria take up and release nitrogen, particularly the dissolved organic nitrogen (DON) fraction (compounds like urea or amino acids). I now use these techniques to address a host of questions relating to the release of DON from phytoplankton and zooplankton and subsequent reincorporation of DON as a nitrogen source for phytoplankton and bacteria. More recently I have started working on DON in effluent - it's surprising how cool waste water treatment plants can be!

Selected Presentations

Mid-Coast Forum on Foreign Relations Presentation (audio only) - January, 2020

House Subcommittee on Water, Oceans, and Wildlife Testimony - February, 2019


  • MK Rogener, RE Sipler, KS Hunter, H Choi, DA Bronk, SB Joye. In press. Pelagic methane oxidation in the northern Chukchi Sea.Limnology and Oceanography. 65: 96-110.
  • Yao, X, RE Sipler, BC Stanley, QN Roberts, MP Sanderson, CB Bott, and DA Bronk. 2019. Quantifying effluent dissolved organic nitrogen (EDON) uptake by microbial communities along a salinity gradient in the York River. Estuaries and Coasts. 42 (5): 1265-1280.
  • Tatters, AO, A Schnetzer, K Xu, NG Walworth, F Fu, JL Spackeen, RE Sipler, EM Bertrand, JB McQuaid, AE Allen, DA Bronk, K Gao, J Sun, DA Caron, DA Hutchins. 2018. Interactive effects of temperature, CO2, and nitrogen source on a coastal California plankton assemblage. Journal of Plankton Research. 40 (2): 151-164. (90)
  • Spackeen JL, DA Bronk, RE Sipler, E Bertrand, DA Hutchins, AE Allen. 2018. Stoichiometric N:P ratios, temperature, and iron impact carbon and nitrogen uptake by Ross Sea microbial communities. Journal of Geophysical Research – Biogeosciences.
  • Spackeen J.L., RE Sipler, EM Bertrand, K Xu, JB McQuaid, N Walworth, DA Hutchins, AE Allen, DA Bronk. 2018. Impact of temperature, CO2, and iron on nutrient uptake by a late season microbial community from the Ross Sea, Antarctica. Aquatic Microbial Ecology. 82: 145-159.
  • Harding, K, K Turk-Kubo, R Sipler, M Mills, D Bronk, and J Zehr. 2018. Symbiotic Unicellular Cyanobacteria Fix Nitrogen in the Arctic Ocean. Proceedings of the National Academy of Science. 115: 13371-13375. doi/10.1073/pnas.1313658115.
  • Bronk, D, RE Sipler, C Bott. 2017. Effluent organic nitrogen produced within waste water treatment plants. Water Environment Research Foundation. ISBN: 978-1-94124-251-3
  • Wawrik, B, D Bronk, S Baer, L Chi, M Sun, J Cooper, and Z Yang. 2017. Bacterial utilization of creatine in seawater. Aquatic Microbial Ecology. 80: 153-165. DOI:
  • Sipler, RE, D. Gong, SE Baer, MP Sanderson, QN Roberts, M Mulholland, DA Bronk. 2017. Contribution of Arctic nitrogen fixation to the global nitrogen budget. Limnology and Oceanography Letters. doi: 10.1002/lol2.10046
  • Spackeen J.L., RE Sipler, MP Sanderson, QN Roberts, K Xu, AO Tatters, N Walworth, DA Hutchins, AE Allen, DA Bronk. 2017. Interactive effects of temperature, CO2, and nitrogen source on a coastal California plankton assemblage: II. Microbial uptake of nitrate, urea, and carbon. Marine Ecology Progress Series. 577: 49-65
  • Sipler, RE, CT Kellogg, TL Connelly, QN Roberts, PL Yager, DA Bronk. 2017. Microbial community response to terrestrially-derived dissolved organic matter in the coastal Arctic. Frontiers in Microbiology. 8:1018. doi: 10.3389/fmicb.2017.01018
  • Baer, SE, RE Sipler, QN Roberts, PL Yager, ME Frischer, and DA Bronk. 2017. Seasonal nitrogen uptake and regeneration in the western coastal Arctic. For Limnology and Oceanography. doi: 10.1002/lno.10580
  • Sipler, RE, SE Baer, TL Connelly, ME Frischer, QN Roberts, PL Yager, DA Bronk. 2017. Chemical and photophysiological impact of terrestrially-derived dissolved organic matter on nitrate uptake in the coastal wester Arctic. Limnology and Oceanography. doi: 10.102/lno.10541