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Award Detail

Doing Business As Name:Duke University
  • Zackary I Johnson
  • (252) 504-7543
Award Date:09/16/2010
Estimated Total Award Amount: $ 600,915
Funds Obligated to Date: $ 600,915
  • FY 2012=$141,497
  • FY 2011=$146,502
  • FY 2013=$128,590
  • FY 2010=$184,326
Start Date:10/01/2010
End Date:09/30/2015
Transaction Type:Grant
Awarding Agency Code:4900
Funding Agency Code:4900
CFDA Number:47.050
Primary Program Source:040100 NSF RESEARCH & RELATED ACTIVIT
Award Title or Description:Collaborative Research: Seasonal and decadal changes in temperature drive Prochlorococcus ecotype distribution patterns
Federal Award ID Number:1031064
DUNS ID:044387793
Parent DUNS ID:044387793

Awardee Location

Street:2200 W. Main St, Suite 710
Awardee Cong. District:01

Primary Place of Performance

Organization Name:Duke University Marine Laboratory
Cong. District:03

Abstract at Time of Award

Intellectual Merit: The two numerically-dominant ecotypes of the marine cyanobacterium Prochlorococcus partition the surface ocean niche latitudinally, with ecotype eMIT9312 dominant in the 30°N-30°S region and eMED4 dominant at higher latitudes. These ecotypes may account for 25-50% of primary production in open ocean ecosystems, but this percentage is dependent on which ecotype dominates. The relative abundance of the two ecotypes follows a log-linear relationship with temperature, with the transition from eMIT9312 to eMED4 occurring at ~18 °C. From these descriptive data, it has been hypothesized that temperature is the primary driver of relative abundance. Their contribution to net primary production, however, appears to be independent of temperature, suggesting temperature regulates ecotype dominance through photosynthesis-independent mechanisms. To test these hypotheses, the PIs are undertaking a series of field and lab studies to investigate the effect of temperature change on the distribution of these ecotypes. Two cruises in the North Pacific will trace the transitions from eMIT9312- to eMED4-dominated regions, with one cruise during the winter and the other during summer. They have hypothesized that the ratio of ecotype abundance will move latitudinally with the seasonal shift in temperature gradient: migration of the 18° C isotherm northward in the summer will be matched by a similar migration of the 1:1 ecotype transition point. Multiple crossings of the 18° C isotherm are proposed, and the summer cruise will also follow the isotherm to the Western US coast to gain insight on physical and geochemical influences. Environmental variables such as nutrient concentrations, light/mixing depths, and virus /grazing based mortality, which may impinge on the relationship between temperature and ecotype ratio, will be assessed through a series of multivariate analyses of the collected suite of physical, chemical and biological data. Seasonal comparisons will be complemented with on-deck incubations and lab competition assays (using existing and new isolates) that will establish, for the first time, how fitness coefficients of these ecotypes relate to temperature. As latitudinal shifts in temperature gradient and migration of ecotypes during seasonal warming likely share common features with high latitude warming as a consequence of climate change, the investigator's analyses will contribute important biological parameters (e.g., abundances, production rates, temperature change coefficients) for modeling biological and biogeochemical responses to climate change. This research will be integrated with that of committed collaborators, generating data sufficient for ecosystem-scale characterizations of the contributions of temperature (relative to other forcing factors) in constraining the range and seasonal migration of these numerically dominant marine phototrophs. Broader Impacts: This proposal encompasses several layers of outreach to the scientific community at large. Biological, chemical and physical data will be deposited in GenBank, NOAA's National Oceanographic Data Center, and the Biological and Chemical Oceanography Data Management Office (BCO-DMO). Results will inform climate and ecosystem-change models, and be used in classrooms as examples of how ocean ecosystems may change in response to climate variation. There are also clear connections to molecular ecology: how do potentially small changes in an organism's genome lead to fundamental differences in their ecology or resiliency to climate change? This project will expand ongoing efforts by establishing formal outreach collaborations for each cruise. These collaborations will be based on two specific goals: (1) a science journalism student will document and broadly communicate the goals and activities of the cruise and (2) a hands-on cruise opportunity for K-12 teachers will serve as an information gateway to other teachers. In addition, this project will support three graduate students (two at Tennessee - an EPSCOR university - and one at Duke) and several undergraduates, composing a significant body of their respective theses. Finally, PIs will continue their efforts to provide opportunities to historically under-represented groups in molecular ecology and ocean sciences.

Publications Produced as a Result of this Research

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Ritchie AE and Johnson ZI "Abundance and genetic diversity of aerobic anoxygenic phototrophic bacteria of coastal regions of the Pacific Ocean" Applied and Environmental Microbiology, v.78, 2012, p.2858. doi:10.1128/AEM.06268-11 

Huntley, Mark E. Johnson, Zackary I. Brown, Susan L. Sills, Deborah L. Gerber, Léda Archibald, Ian Machesky, Stephen C. Granados, Joe Beal, Colin Greene, Charles H. "Demonstrated large-scale production of marine microalgae for fuels and feed" Algal Research, v.10, 2015, p.. doi:10.1016/j.algal.2015.04.016 

Bittar TB, Lin Y, Sassano LR, Wheeler BJ, Brown SL, Cochlan WP and Johnson ZI "Carbon allocation under light and nitrogen resource gradients in two model marine phytoplankton." Journal of Phycology, v.49, 2013, p.523-535. doi:10.1111/jpy.12060 

Ribalet, Francois Swalwell, Jarred Clayton, Sophie Jiménez, Valeria Sudek, Sebastian Lin, Yajuan Johnson, Zackary I. Worden, Alexandra Z. Armbrust, E. Virginia "Light-driven synchrony of Prochlorococcus growth and mortality in the subtropical Pacific gyre" PNAS, v.112, 2015, p.. doi:10.1073/pnas.1424279112 

Morris JJ, Johnson ZI, Szul MJ, Keller M, Zinser ER "Dependence of the cyanobacterium Prochlorococcus on hydrogen peroxide scavenging microbes for growth at the oceanâ??s surface." PLoS One, v.6(2), 2011, p.16805. doi:10.1371/journal.pone.0016805 

Ringuet S, Sassano L, Johnson ZI "A suite of microplate reader-based colorimetric methods to quantify ammonium, nitrate, orthophosphate and silicate concentrations for aquatic nutrient monitoring" Journal of Environmental Monitoring, v., 2011, p.. doi:10.1039/C0EM00290A 

Wang X, Singh P, Gao Z, Zhang X, Johnson ZI, Wang G "Distribution and Diversity of Planktonic Fungi in the West Pacific Warm Pool" PLoS One, v.9, 2014, p.. doi:10.1371/journal.pone.0101523 

Yung, Cheuk-Man Vereen, Marissa K. Herbert, Amy Davis, Katherine M. Yang, Jiayu Kantorowska, Agata Ward, Christopher S. Wernegreen, Jennifer J. Johnson, Zackary I. Hunt, Dana E. "Thermally adaptive tradeoffs in closely-related marine bacterial strains" Environmental Microbiology, v.17, 2015, p.. doi:10.1111/1462-2920.12714 

Kopf et al. "The Ocean Sampling Day Consortium" GigaScience, v.4, 2015, p.. doi:10.1186/s13742-015-0066-5 

JM Rowe, JM DeBruyn, L Poorvin, GR LeCleir, ZI Johnson, ER Zinser, and Wilhelm SW "Viral and bacterial abundance and production in the Western Pacific Ocean and the relation to other oceanic realms" FEMS Microbiology Ecology, v.72, 2012, p.359. doi:10.1111/j.1574-6941.2011.01223.x 

Dupont C, Valas R, McCrow J, Moustafa A, Walworth N, Goodenough U, Roth R, Hogle S, Bai J, Johnson ZI, Mann E, Palenik B, Barbeau K, Venter JC, Allen AE "Genomes and gene expression across light and productivity gradients in eastern subtropical Pacific microbial communities" ISME Journal, v., 2014, p.. doi:10.1038/ismej.2014.198 

Johnson ZI, and DW Johnston "Smartphones: Powerful Tools for Geoscience Education" Eos, Transactions American Geophysical Union, v.94, 2013, p.. doi:10.1002/2013EO470001 

Yates, K.K. Turley, C. Hopkinson, B.M. Todgham, A.E. Cross, J.N. Greening, H. Williamson, P. Van Hooidonk, R. DeheynD.D. Johnson, Z "Transdisciplinary science: A path to understanding the interactions among ocean acidification, ecosystems, and society" Oceanography, v.28, 2015, p.. doi:10.5670/oceanog.2015.43 

Lin Y, Gazsi K, Lance VP, Larkin A, Chandler J, Zinser ER, and Johnson ZI "In situ activity of a dominant Prochlorococcus ecotype (eHL-II) from rRNA content and cell size." Environmental Microbiology, v.n/a, 2013, p.n/a. doi:10.1111/1462-2920.12135 

Hunt DE, Lin Y, Church MJ, Karl DM, Izzo LK, Tringe SG and Johnson ZI "The relationship between abundance and specific activity of bacterioplankton in open ocean surface waters." Applied and Environmental Microbiology, v.79, 2013, p.177-184. doi:10.1128/AEM.02155-12 

Jiao N, Luo T, Zhang R, Yan W, Lin Y, Johnson ZI, Tian J, Yuan, D, Yang Q, Sun J, Hu D and Wang P "Presence of Prochlorococcus in the aphotic waters of the western Pacific Ocean" Biogeosciences Discussions, v.10, 2013, p.9345-9371. doi:10.5194/bgd-10-9345-2013 

Ferrón, S; Ho, D; Johnson, Z; Huntley, M "Air-water fluxes of N2O and CH4 during microalgae cultivation (Staurosira sp.) in an open raceway pond." Environmental Science & Technology, v.(2012), 2012, p.10842. doi:10.1021/es302396jy 

Johnson ZI, Wheeler BJ, Blinebry SK, Carlson CM, Ward CS, and Hunt DE "Dramatic variability of the carbonate system at a temperate coastal ocean site (Beaufort, North Carolina, USA) is regulated by physical and biogeochemical processes on multiple timescales" PLoS ONE, v., 2013, p.. doi:10.1371/journal.pone.0085117 

Johnson ZI, Martiny AC "Techniques for Quantifying Phytoplankton Biodiversity" Annual Review of Marine Science, v.7, 2015, p.. doi:10.1146/annurev-marine-010814-015902 

Project Outcomes Report


This Project Outcomes Report for the General Public is displayed verbatim as submitted by the Principal Investigator (PI) for this award. Any opinions, findings, and conclusions or recommendations expressed in this Report are those of the PI and do not necessarily reflect the views of the National Science Foundation; NSF has not approved or endorsed its content.

The collaborative research project titled "Seasonal and decadal changes in temperature drive Prochlorococcus ecotype distribution patterns" was a joint effort between Duke University and University of Tennessee Knoxville and encompassed 4 research cruises (over 100 days at sea) and traversed the Northern Pacific Ocean multiple times over multiple seasons. The project trained numerous undergraduates, graduate students and postdocs and involved collaborating scientists from other institutions as well as school teachers, journalism students and other non-professionals. The goal of the project was to investigate how the diversity and activity of Prochlorococcus, the most abundant phytoplankton in the open ocean, responds to temperature changes as a function of latitude and seasons.  Our broader goal was to put these findings in to the context of climate change, which is expected to result in increasing ocean temperatures.  Towards these goals we used the latest techniques in physiology and molecular ecology, and developed some new approaches that allow the assessment of the activity of genetically distinct types of Prochlorococcus (as well as other marine microbes).  Using these laboratory- and field-based approaches, we discovered that Prochlorococcus is much more diverse than previously thought, and that it is composed of >1000 different “species.”  These species differentially respond to environmental change, with some optimized for unique environments (e.g. combinations of nutrients, temperature, etc.) while others are apparently regulated by interactions with other organisms (e.g. viruses, grazers, other microbes).  Further, we found that these different types of Prochlorococcus have different impacts on the carbon cycle (and presumably the marine foodweb), with some having tightly temperature controlled carbon dioxide uptake whereas others are differentially regulated.  All types respond to environmental variability on multiple time scales and this variability can be seen in the diversity and activity of Prochlorococcus across multiple space and time scales. Projecting these findings into future climate scenarios, it is clear that Prochlorococcus cannot be treated a single organisms, but the extent and nature of its molecular diversity must be taken into account to understand the carbon cycle and ocean ecology of future oceans.  In addition to numerous publications and public presentations, these findings have been communicated to a broad array of educators and incorporated into K-12 lessons plans as well as undergraduate and graduate courses. Data from this project is publically available on BCO-DMO ( with additional molecular data available from NCBI ( Finally, this project has supported our team to interact, educate and to help inspire the broader public and future scientists through an array of open houses, classroom visits, "adopt-a-teacher" programs, and other public educational forums.

Last Modified: 12/30/2015
Modified by: Zackary I Johnson

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