Behrenfeld, Michael: Oregon State University (Project Lead)
Milligan, Allen: Oregon State University (Co-Investigator)
Graff, Jason: Oregon State University (Participant)
Project Funding:
2010 - 2015
NRA: 2009 NOPP: National Oceanographic Partnership Program Broad Agency Announcement
Funded by NASA
Abstract:
This research project is focused on the development of a technique for routinely assessing phytoplankton carbon biomass (Cphyto) in the field. If successful, this investment will create a foundation for (1) evaluating and evolving new satellite Cphyto products, (2) characterizing light- and nutrient-stress effects in the field independently of radiotracer measurements, and (3) distinguishing physiological- and biomass-responses to climate forcings in satellite time-series of ocean color (Fig. 1). The measurement and future validated retrieval of phytoplantkon biomass is essential for understanding global ocean carbon pools and fluxes and for detecting changes in this key carbon stock over time.
Throughout the history of satellite ocean color measurements, chlorophyll concentration has functioned as the primary parameter retrieved from space related to the abundance of phytoplankton in the upper ocean. The relationship between phytoplankton biomass and chlorophyll concentration, however, is highly variable due to physiological adjustments in intracellular pigmentation resulting from variations in light and nutrient conditions of the mixed layer. Indeed, phytoplankton Chl:C ratios can vary by nearly 2 orders of magnitude (Geider 1987, Behrenfeld et al. 2005). Recently, an approach has emerged for directly estimating Cphyto from remote sensing retrievals of particle backscattering (Behrenfeld et al. 2005). Multiple studies have attempted to evaluate the scattering-biomass relationship, but true validation of satellite Cphyto products remains impossible due to a near complete lack of field Cphyto estimates. The current proposed study will develop a technique for measuring Cphyto and demonstrate its application in the field. Our approach is multifaceted to improve the probability of success, including both flow-cytometer sample analysis and construction of a new liquid-aperture particle counter/sizer.
This work directly addresses the objectives of NASA’s Ocean Biology and Biogeochemistry program by providing new scientific evaluation capabilities for novel space-based measurements of global ocean phytoplankton communities that will improve ocean productivity estimates and lead to robust satellite physiological products for comparison with ocean biogeochemical-ecosystem models.
Publications:
Jones, B. M., Halsey, K. H., Behrenfeld, M. J. 2017. Novel incubation-free approaches to determine phytoplankton net primary productivity, growth, and biomass based on flow cytometry and quantification of ATP and NAD(H). Limnology and Oceanography: Methods. 15(11), 928-938. DOI: 10.1002/lom3.10213
Behrenfeld, M. J., O'Malley, R. T., Boss, E. S., Westberry, T. K., Graff, J. R., Halsey, K. H., Milligan, A. J., Siegel, D. A., Brown, M. B. 2015. Revaluating ocean warming impacts on global phytoplankton. Nature Climate Change. 6(3), 323-330. DOI: 10.1038/NCLIMATE2838
Graff, J. R., Westberry, T. K., Milligan, A. J., Brown, M. B., Dall'Olmo, G., Dongen-Vogels, V. V., Reifel, K. M., Behrenfeld, M. J. 2015. Analytical phytoplankton carbon measurements spanning diverse ecosystems. Deep Sea Research Part I: Oceanographic Research Papers. 102, 16-25. DOI: 10.1016/j.dsr.2015.04.006
Behrenfeld, M. J. 2014. Climate-mediated dance of the plankton. Nature Climate Change. 4(10), 880-887. DOI: 10.1038/NCLIMATE2349
Behrenfeld, M. J., Doney, S. C., Lima, I., Boss, E. S., Siegel, D. A. 2013. Annual cycles of ecological disturbance and recovery underlying the subarctic Atlantic spring plankton bloom. Global Biogeochemical Cycles. 27(2), 526-540. DOI: 10.1002/gbc.20050
Behrenfeld, M. J., Boss, E. S. 2014. Resurrecting the Ecological Underpinnings of Ocean Plankton Blooms. Annual Review of Marine Science. 6(1), 167-194. DOI: 10.1146/annurev-marine-052913-021325
Behrenfeld, M. J., Hu, Y., Hostetler, C. A., Dall'Olmo, G., Rodier, S. D., Hair, J. W., Trepte, C. R. 2013. Space-based lidar measurements of global ocean carbon stocks. Geophysical Research Letters. 40(16), 4355-4360. DOI: 10.1002/grl.50816
Siegel, D. A., Behrenfeld, M. J., Maritorena, S., McClain, C. R., Antoine, D., Bailey, S. W., Bontempi, P. S., Boss, E. S., Dierssen, H. M., Doney, S. C., Eplee, R. E., Evans, R. H., Feldman, G. C., Fields, E., Franz, B. A., Kuring, N. A., Mengelt, C., Nelson, N. B., Patt, F. S., Robinson, W. D., Sarmiento, J. L., Swan, C. M., Werdell, P. J., Westberry, T. K., Wilding, J. G., Yoder, J. A. 2013. Regional to global assessments of phytoplankton dynamics from the SeaWiFS mission. Remote Sensing of Environment. 135, 77-91. DOI: 10.1016/j.rse.2013.03.025
Graff, J. R., Milligan, A. J., Behrenfeld, M. J. 2012. The measurement of phytoplankton biomass using flow-cytometric sorting and elemental analysis of carbon. Limnology and Oceanography: Methods. 10(11), 910-920. DOI: 10.4319/lom.2012.10.910
More details may be found in the following project profile(s):
