Haëntjens
Nils
Haëntjens
Nils
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ArticleExpanding Tara oceans protocols for underway, ecosystemic sampling of the ocean-atmosphere interface during Tara Pacific expedition (2016-2018)(Frontiers Media, 2019-12-11) Gorsky, Gabriel ; Bourdin, Guillaume ; Lombard, Fabien ; Pedrotti, Maria Luiza ; Audrain, Samuel ; Bin, Nicolas ; Boss, Emmanuel S. ; Bowler, Chris ; Cassar, Nicolas ; Caudan, Loic ; Chabot, Genevieve ; Cohen, Natalie R. ; Cron, Daniel ; De Vargas, Colomban ; Dolan, John R. ; Douville, Eric ; Elineau, Amanda ; Flores, J. Michel ; Ghiglione, Jean-Francois ; Haëntjens, Nils ; Hertau, Martin ; John, Seth G. ; Kelly, Rachel L. ; Koren, Ilan ; Lin, Yajuan ; Marie, Dominique ; Moulin, Clémentine ; Moucherie, Yohann ; Pesant, Stephane ; Picheral, Marc ; Poulain, Julie ; Pujo-Pay, Mireille ; Reverdin, Gilles ; Romac, Sarah ; Sullivan, Mathew B. ; Trainic, Miri ; Tressol, Marc ; Troublé, Romain ; Vardi, Assaf ; Voolstra, Christian R. ; Wincker, Patrick ; Agostini, Sylvain ; Banaigs, Bernard ; Boissin, Emilie ; Forcioli, Didier ; Furla, Paola ; Galand, Pierre E. ; Gilson, Eric ; Reynaud, Stephanie ; Sunagawa, Shinichi ; Thomas, Olivier P. ; Vega Thurber, Rebecca ; Zoccola, Didier ; Planes, Serge ; Allemand, Denis ; Karsenti, EricInteractions between the ocean and the atmosphere occur at the air-sea interface through the transfer of momentum, heat, gases and particulate matter, and through the impact of the upper-ocean biology on the composition and radiative properties of this boundary layer. The Tara Pacific expedition, launched in May 2016 aboard the schooner Tara, was a 29-month exploration with the dual goals to study the ecology of reef ecosystems along ecological gradients in the Pacific Ocean and to assess inter-island and open ocean surface plankton and neuston community structures. In addition, key atmospheric properties were measured to study links between the two boundary layer properties. A major challenge for the open ocean sampling was the lack of ship-time available for work at “stations”. The time constraint led us to develop new underway sampling approaches to optimize physical, chemical, optical, and genomic methods to capture the entire community structure of the surface layers, from viruses to metazoans in their oceanographic and atmospheric physicochemical context. An international scientific consortium was put together to analyze the samples, generate data, and develop datasets in coherence with the existing Tara Oceans database. Beyond adapting the extensive Tara Oceans sampling protocols for high-resolution underway sampling, the key novelties compared to Tara Oceans’ global assessment of plankton include the measurement of (i) surface plankton and neuston biogeography and functional diversity; (ii) bioactive trace metals distribution at the ocean surface and metal-dependent ecosystem structures; (iii) marine aerosols, including biological entities; (iv) geography, nature and colonization of microplastic; and (v) high-resolution underway assessment of net community production via equilibrator inlet mass spectrometry. We are committed to share the data collected during this expedition, making it an important resource important resource to address a variety of scientific questions.
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ArticlePlankton imagery data inform satellite-based estimates of diatom carbon(American Geophysical Union, 2022-06-18) Chase, Alison P. ; Boss, Emmanuel S. ; Haëntjens, Nils ; Culhane, Emmett ; Roesler, Collin S. ; Karp-Boss, LeeEstimating the biomass of phytoplankton communities via remote sensing is a key requirement for understanding global ocean ecosystems. Of particular interest is the carbon associated with diatoms given their unequivocal ecological and biogeochemical roles. Satellite-based algorithms often rely on accessory pigment proxies to define diatom biomass, despite a lack of validation against independent diatom biomass measurements. We used imaging-in-flow cytometry to quantify diatom carbon in the western North Atlantic, and compared results to those obtained from accessory pigment-based approximations. Based on this analysis, we offer a new empirical formula to estimate diatom carbon concentrations from chlorophyll a. Additionally, we developed a neural network model in which we integrated chlorophyll a and environmental information to estimate diatom carbon distributions in the western North Atlantic. The potential for improving satellite-based diatom carbon estimates by integrating environmental information into a model, compared to models that are based solely on chlorophyll a, is discussed.
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ArticleSeasonal mixed layer depth shapes phytoplankton physiology, viral production, and accumulation in the North Atlantic(Nature Research, 2021-11-17) Diaz, Ben P. ; Knowles, Benjamin ; Johns, Christopher T. ; Laber, Christien P. ; Bondoc, Karen Grace V. ; Haramaty, Liti ; Natale, Frank ; Harvey, Elizabeth L. ; Kramer, Sasha J. ; Bolaños, Luis M. ; Lowenstein, Daniel P. ; Fredricks, Helen F. ; Graff, Jason R. ; Westberry, Toby K. ; Mojica, Kristina D. A. ; Haëntjens, Nils ; Baetge, Nicholas ; Gaube, Peter ; Boss, Emmanuel S. ; Carlson, Craig A. ; Behrenfeld, Michael J. ; Van Mooy, Benjamin A. S. ; Bidle, Kay D.Seasonal shifts in phytoplankton accumulation and loss largely follow changes in mixed layer depth, but the impact of mixed layer depth on cell physiology remains unexplored. Here, we investigate the physiological state of phytoplankton populations associated with distinct bloom phases and mixing regimes in the North Atlantic. Stratification and deep mixing alter community physiology and viral production, effectively shaping accumulation rates. Communities in relatively deep, early-spring mixed layers are characterized by low levels of stress and high accumulation rates, while those in the recently shallowed mixed layers in late-spring have high levels of oxidative stress. Prolonged stratification into early autumn manifests in negative accumulation rates, along with pronounced signatures of compromised membranes, death-related protease activity, virus production, nutrient drawdown, and lipid markers indicative of nutrient stress. Positive accumulation renews during mixed layer deepening with transition into winter, concomitant with enhanced nutrient supply and lessened viral pressure.
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Working PaperEXPORTS Measurements and Protocols for the NE Pacific Campaign(NASA STI Program and Woods Hole Oceanographic Institution, 2021-02) Behrenfeld, Michael J. ; Benitez-Nelson, Claudia R. ; Boss, Emmanuel S. ; Brzezinski, Mark A. ; Buck, Kristen N. ; Buesseler, Ken O. ; Burd, Adrian B. ; Carlson, Craig A. ; Cassar, Nicolas ; Cetinić, Ivona ; Close, Hilary G. ; Craig, Susanne E. ; D'Asaro, Eric A. ; Durkin, Colleen A. ; Estapa, Margaret L. ; Fassbender, Andrea ; Fox, James ; Freeman, Scott ; Gifford, Scott M. ; Gong, Weida ; Graff, Jason R. ; Gray, Deric ; Guidi, Lionel ; Halsey, Kim ; Hansell, Dennis A. ; Haëntjens, Nils ; Horner, Tristan J. ; Jenkins, Bethany D. ; Jones, Janice L. ; Karp-Boss, Lee ; Kramer, Sasha J. ; Lam, Phoebe J. ; Lee, Craig M. ; Lee, Jong-Mi ; Liu, Shuting ; Mannino, Antonio ; Maas, Amy E. ; Marchal, Olivier ; Marchetti, Adrian ; McDonnell, Andrew M. P. ; McNair, Heather ; Menden-Deuer, Susanne ; Morison, Francoise ; Nelson, Norman B. ; Nicholson, David P. ; Niebergall, Alexandria K. ; Omand, Melissa M. ; Passow, Uta ; Perry, Mary J. ; Popp, Brian N. ; Proctor, Chris ; Rafter, Patrick ; Roca-Martí, Montserrat ; Roesler, Collin S. ; Rubin, Edwina ; Rynearson, Tatiana A. ; Santoro, Alyson E. ; Siegel, David A. ; Sosik, Heidi M. ; Soto Ramos, Inia ; Stamieszkin, Karen ; Steinberg, Deborah K. ; Stephens, Brandon M. ; Thompson, Andrew F. ; Van Mooy, Benjamin A. S. ; Zhang, XiaodongEXport Processes in the Ocean from Remote Sensing (EXPORTS) is a large-scale NASA-led and NSF co-funded field campaign that will provide critical information for quantifying the export and fate of upper ocean net primary production (NPP) using satellite information and state of the art technology.
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ArticleAn operational overview of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) Northeast Pacific field deployment(University of California Press, 2021-07-07) Siegel, David A. ; Cetinić, Ivona ; Graff, Jason R. ; Lee, Craig M. ; Nelson, Norman B. ; Perry, Mary J. ; Soto Ramos, Inia ; Steinberg, Deborah K. ; Buesseler, Ken O. ; Hamme, Roberta C. ; Fassbender, Andrea ; Nicholson, David P. ; Omand, Melissa M. ; Robert, Marie ; Thompson, Andrew F. ; Amaral, Vinicius ; Behrenfeld, Michael J. ; Benitez-Nelson, Claudia R. ; Bisson, Kelsey ; Boss, Emmanuel S. ; Boyd, Philip ; Brzezinski, Mark A. ; Buck, Kristen N. ; Burd, Adrian B. ; Burns, Shannon ; Caprara, Salvatore ; Carlson, Craig A. ; Cassar, Nicolas ; Close, Hilary G. ; D'Asaro, Eric A. ; Durkin, Colleen A. ; Erickson, Zachary K. ; Estapa, Margaret L. ; Fields, Erik ; Fox, James ; Freeman, Scott ; Gifford, Scott M. ; Gong, Weida ; Gray, Deric ; Guidi, Lionel ; Haëntjens, Nils ; Halsey, Kim ; Huot, Yannick ; Hansell, Dennis A. ; Jenkins, Bethany D. ; Karp-Boss, Lee ; Kramer, Sasha J. ; Lam, Phoebe J. ; Lee, Jong-Mi ; Maas, Amy E. ; Marchal, Olivier ; Marchetti, Adrian ; McDonnell, Andrew M. P. ; McNair, Heather ; Menden-Deuer, Susanne ; Morison, Francoise ; Niebergall, Alexandria K. ; Passow, Uta ; Popp, Brian N. ; Potvin, Geneviève ; Resplandy, Laure ; Roca-Martí, Montserrat ; Roesler, Collin S. ; Rynearson, Tatiana A. ; Traylor, Shawnee ; Santoro, Alyson E. ; Seraphin, Kanesa ; Sosik, Heidi M. ; Stamieszkin, Karen ; Stephens, Brandon M. ; Tang, Weiyi ; Van Mooy, Benjamin ; Xiong, Yuanheng ; Zhang, XiaodongThe goal of the EXport Processes in the Ocean from RemoTe Sensing (EXPORTS) field campaign is to develop a predictive understanding of the export, fate, and carbon cycle impacts of global ocean net primary production. To accomplish this goal, observations of export flux pathways, plankton community composition, food web processes, and optical, physical, and biogeochemical (BGC) properties are needed over a range of ecosystem states. Here we introduce the first EXPORTS field deployment to Ocean Station Papa in the Northeast Pacific Ocean during summer of 2018, providing context for other papers in this special collection. The experiment was conducted with two ships: a Process Ship, focused on ecological rates, BGC fluxes, temporal changes in food web, and BGC and optical properties, that followed an instrumented Lagrangian float; and a Survey Ship that sampled BGC and optical properties in spatial patterns around the Process Ship. An array of autonomous underwater assets provided measurements over a range of spatial and temporal scales, and partnering programs and remote sensing observations provided additional observational context. The oceanographic setting was typical of late-summer conditions at Ocean Station Papa: a shallow mixed layer, strong vertical and weak horizontal gradients in hydrographic properties, sluggish sub-inertial currents, elevated macronutrient concentrations and low phytoplankton abundances. Although nutrient concentrations were consistent with previous observations, mixed layer chlorophyll was lower than typically observed, resulting in a deeper euphotic zone. Analyses of surface layer temperature and salinity found three distinct surface water types, allowing for diagnosis of whether observed changes were spatial or temporal. The 2018 EXPORTS field deployment is among the most comprehensive biological pump studies ever conducted. A second deployment to the North Atlantic Ocean occurred in spring 2021, which will be followed by focused work on data synthesis and modeling using the entire EXPORTS data set.
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ArticleToward a synthesis of phytoplankton communities composition methods for global-scale application(Association for the Sciences of Limnology and Oceanography (ASLO), 2024-02-23) Kramer, Sasha J. ; Bolanos, Luis M. ; Catlett, Dylan ; Chase, Alison P. ; Behrenfeld, Michael J. ; Boss, Emmanuel S. ; Crockford, E. Taylor ; Giovannoni, Stephen J. ; Graff, Jason R. ; Haentjens, Nils ; Karp-Boss, Lee ; Peacock, Emily E. ; Roesler, Collin S. ; Sosik, Heidi M. ; Siegel, David A.The composition of the marine phytoplankton community has been shown to impact many biogeochemical processes and marine ecosystem services. A variety of methods exist to characterize phytoplankton community composition (PCC), with varying degrees of taxonomic resolution. Accordingly, the resulting PCC determinations are dependent on the method used. Here, we use surface ocean samples collected in the North Atlantic and North Pacific Oceans to compare high-performance liquid chromatography pigment-based PCC to four other methods: quantitative cell imaging, flow cytometry, and 16S and 18S rRNA amplicon sequencing. These methods allow characterization of both prokaryotic and eukaryotic PCC across a wide range of size classes. PCC estimates of many taxa resolved at the class level (e.g., diatoms) show strong positive correlations across methods, while other groups (e.g., dinoflagellates) are not well captured by one or more methods. Since variations in phytoplankton pigment concentrations are related to changes in optical properties, this combined dataset expands the potential scope of ocean color remote sensing by associating PCC at the genus- and species-level with group- or class-level PCC from pigments. Quantifying the strengths and limitations of pigment-based PCC methods compared to PCC assessments from amplicon sequencing, imaging, and cytometry methods is the first step toward the robust validation of remote sensing approaches to quantify PCC from space.