Cellular elemental content of individual phytoplankton cells collected during US GEOTRACES North Atlantic Transect cruises in the Subtropical western and eastern North Atlantic Ocean during Oct and Nov, 2010 and Nov. 2011.

Dataset: GT10-11 - cellular element quotasPhytoplankton contribute significantly to global C cycling and serve as the base of ocean food webs. Phytoplankton require trace metals for growth and also mediate the vertical distributions of many metals in the ocean. This dataset provides direct measurements of metal quotas in phytoplankton from across the North Atlantic Ocean, known to be subjected to aeolian Saharan inputs and anthropogenic inputs from North America and Europe. Bulk particulate material and individual phytoplankton cells were collected from the upper water column (<150 m) as part of the US GEOTRACES North Atlantic Zonal Transect cruises (KN199-4, KN199-5, KN204-1A,B). The cruise tracks spanned several ocean biomes and geochemical regions. Chemical leaches (to extract biogenic and otherwise labile particulate phases) are combined together with synchrotron X-ray fluorescence (SXRF) analyses of individual micro and nanophytoplankton to discern spatial trends across the basin. Individual phytoplankton cells were analyzed for elemental content using SXRF (Synchrotron radiation X-Ray Fluorescence). Carbon was calculated from biovolume using the relationships of Menden-Deuer & Lessard (2000).NSF Ocean Sciences (NSF OCE) OCE-092828

Element quotas of individual Synechococcus cells collected during Bermuda Atlantic Time-series Study (BATS) cruises aboard the R/V Atlantic Explorer between dates 2012-07-11 and 2013-10-13

Dataset: Cellular element quotas: Si in Synechococcus cellsThese data include element quotas of individual Synechococcus cells collected during Bermuda Atlantic Time-series Study (BATS) cruises. The three cruises (AE1218,AE1228, and AE1322) were all aboard the R/V Atlantic Explorer between dates 2012-07-11 and 2013-10-13 around Bermuda. Instruments used were a CTD profiler, and a Synchrotron X-ray Fluorescence Microprobe (SXRF). Understanding the accumulation of silicon by marine picocyanobacteria of the genus Synechococcus has the potential to drive a major paradigm shift in our understanding of biogenic silica cycling in the ocean. These data assess the contribution of Synechococcus to total biogenic silica and were collected by Dr. Benjamin Twining of the Bigelow Laboratory for Ocean Sciences as part of the project Understanding the Role of Picocyanobacteria in the Marine Silicate Cycle. For a complete list of measurements, refer to the supplemental document 'Field_names.pdf', and a full dataset description is included in the supplemental file 'Dataset_description.pdf'. The most current version of this dataset is available at: http://www.bco-dmo.org/dataset/644840NSF Ocean Sciences (NSF OCE) OCE-1131139, NSF Ocean Sciences (NSF OCE) OCE-1335012, NSF Ocean Sciences (NSF OCE) OCE-113104

The Unique Biogeochemical Signature of the Marine Diazotroph Trichodesmium

The elemental composition of phytoplankton can depart from canonical Redfield values under conditions of nutrient limitation or production (e.g., N fixation). Similarly, the trace metal metallome of phytoplankton may be expected to vary as a function of both ambient nutrient concentrations and the biochemical processes of the cell. Diazotrophs such as the colonial cyanobacteria Trichodesmium are likely to have unique metal signatures due to their cell physiology. We present metal (Fe, V, Zn, Ni, Mo, Mn, Cu, Cd) quotas for Trichodesmium collected from the Sargasso Sea which highlight the unique metallome of this organism. The element concentrations of bulk colonies and trichomes sections were analyzed by ICP-MS and synchrotron x-ray fluorescence, respectively. The cells were characterized by low P contents but enrichment in V, Fe, Mo, Ni, and Zn in comparison to other phytoplankton. Vanadium was the most abundant metal in Trichodesmium, and the V quota was up to fourfold higher than the corresponding Fe quota. The stoichiometry of 600C:101N:1P (mol mol−1) reflects P-limiting conditions. Iron and V were enriched in contiguous cells of 10 and 50% of Trichodesmium trichomes, respectively. The distribution of Ni differed from other elements, with the highest concentration in the transverse walls between attached cells. We hypothesize that the enrichments of V, Fe, Mo, and Ni are linked to the biochemical requirements for N fixation either directly through enrichment in the N-fixing enzyme nitrogenase or indirectly by the expression of enzymes responsible for the removal of reactive oxygen species. Unintentional uptake of V via P pathways may also be occurring. Overall, the cellular content of trace metals and macronutrients differs significantly from the (extended) Redfield ratio. The Trichodesmium metallome is an example of how physiology and environmental conditions can cause significant deviations from the idealized stoichiometry

Comparison of particulate trace element concentrations in the North Atlantic Ocean as determined with discrete bottle sampling and in situ pumping

Author Posting. © The Author(s), 2014. This is the author's version of the work. It is posted here by permission of Elsevier for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 116 (2015): 272-282, doi:10.1016/j.dsr2.2014.11.005.The oceanic geochemical cycles of many metals are controlled, at least in part, by interactions with particulate matter, and measurements of particulate trace metals are a core component of the international GEOTRACES program. Particles can be collected by several methods, including in-line filtration from sample bottles and in situ pumping. Both approaches were used to collect particles from the water column on the U.S. GEOTRACES North Atlantic Zonal Transect cruises. Statistical comparison of 91 paired samples collected at matching stations and depths indicate mean concentrations within 5% for Fe and Ti, within 10% for Cd, Mn and Co, and within 15% for Al. Particulate concentrations were higher in bottle samples for Cd, Mn and Co but lower in bottle samples for Fe, Al and Ti, suggesting that large lithogenic particles may be undersampled by bottles in near-shelf environments. In contrast, P was 58% higher on average in bottle samples. This is likely due to a combination of analytical offsets between lab groups, differences in filter pore size, and potential loss of labile P from pump samples following misting with deionized water. Comparable depth profiles were produced by the methods across a range of conditions in the North Atlantic.This work was funded by grants from the US National Science Foundation to BST (OCE-0928289) and PJL (OCE-0963026) as part of the US GEOTRACES North Atlantic Zonal Transect program

Variations in Synechococcus Cell Quotas of Phosphorus, Sulfur, Manganese, Iron, Nickel, and Zinc within Mesoscale Eddies in the Sargasso Sea

The quotas of P, S, Mn, Fe, Ni, and Zn in individual Synechococcus cells collected from the surface and deep chlorophyll maximum (DCM) layer of three mesoscale eddies in the Sargasso Sea were measured using synchrotron X-ray fluorescence microscopy. Cells in a mode-water eddy had significantly higher P (57 +/- 10 amol) and Mn (28 +/- 7 zmol) cell quotas than cells collected from a cyclone (22 +/- 2 amol and 10 +/- 1 zmol, respectively) or anticyclone (25 +/- 3 amol and 18 +/- 3 zmol, respectively). Conversely, Ni and Zn quotas were significantly higher in the cells from the anticyclone (92 +/- 19 and 561 +/- 150 zmol, respectively) than in cells from the cyclonic (25 +/- 4 and 35 +/- 7 zmol, respectively) or mode-water (30 +/- 9 and 21 +/- 8 zmol, respectively) eddies. These changes may reflect biochemical responses (e. g., production of urease and alkaline phosphatase) to gradients in inorganic N and P supplies. Cellular quotas of Fe (111 +/- 17 zmol in the cyclone) and S (52 +/- 6 amol in the cyclone) did not vary significantly among eddies despite two-to threefold higher dissolved and particulate Fe concentrations in the anticylone. Cells collected from 10-m depth contained approximately 80% more Ni and S than cells collected from the DCM, potentially reflecting cell responses to heightened oxidative stress. Depth-related trends varied by eddy for the other elements. Cellular P and Zn varied significantly during repeated samplings of the cyclone, with quotas of both elements dropping as bulk chlorophyll biomass in the DCM increased. These data demonstrate the dynamic responses of phytoplankton elemental composition to physical and chemical environmental gradients

US National BioGeoSCAPES Workshop Report

Virtual Meeting held November 10-12, 2021BioGeoSCAPES (BGS) is an international program being developed to understand controls on ocean productivity and metabolism by integrating systems biology (‘omics) and biogeochemistry (Figure 1). To ensure global input into the design of the BGS Program, countries interested in participating were tasked with holding an organizing meeting to discuss the country-specific research priorities. A United States BGS planning meeting, sponsored by the Ocean Carbon & Biogeochemistry (OCB) Project Office, was convened virtually November 10-12, 2021. The objectives of the meeting were to communicate the planning underway by international partners, engage the US community to explore possible national contributions to such a program, and build understanding, support, and momentum for US efforts towards BGS. The meeting was well-attended, with 154 participants and many fruitful discussions that are summarized in this document. Key outcomes from the meeting were the identification of additional programs and partners for BGS, a prioritization of measurements requiring intercalibration, and the development of a consensus around key considerations to be addressed in a science plan. Looking forward, the hope is that this workshop will serve as the foundation for future US and international discussions and planning for a BGS program, enabled by NSF funding for an AccelNet project (AccelNet - Implementation: Development of an International Network for the Study of Ocean Metabolism and Nutrient Cycles on a Changing Planet (BioGeoSCAPES)), beginning in 2022.This workshop was held thanks to funding to US OCB by the National Science Foundation (NSF) (OCE-1850983) and National Aeronautic and Space Administration (NASA) (NNX17AB17G). The organizers give thanks to all workshop participants for their thoughtful discussions and input during the workshop

Quantification of phosphorus in single cells using synchrotron X-ray fluorescence

Phosphorus abundance was quantified in individual phytoplankton cells by synchrotron X-ray fluorescence and compared with bulk spectrophotometric measurements to confirm accuracy of quantification. Figures of merit for P quantification on three different types of transmission electron microscopy grids are compared to assess possible interferences

A dissolved cobalt plume in the oxygen minimum zone of the eastern tropical South Pacific

© The Author(s), 2016. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Biogeosciences 13 (2016): 5697-5717, doi:10.5194/bg-13-5697-2016.Cobalt is a nutrient to phytoplankton, but knowledge about its biogeochemical cycling is limited, especially in the Pacific Ocean. Here, we report sections of dissolved cobalt and labile dissolved cobalt from the US GEOTRACES GP16 transect in the South Pacific. The cobalt distribution is closely tied to the extent and intensity of the oxygen minimum zone in the eastern South Pacific with highest concentrations measured at the oxycline near the Peru margin. Below 200 m, remineralization and circulation produce an inverse relationship between cobalt and dissolved oxygen that extends throughout the basin. Within the oxygen minimum zone, elevated concentrations of labile cobalt are generated by input from coastal sources and reduced scavenging at low O2. As these high cobalt waters are upwelled and advected offshore, phytoplankton export returns cobalt to low-oxygen water masses underneath. West of the Peru upwelling region, dissolved cobalt is less than 10 pM in the euphotic zone and strongly bound by organic ligands. Because the cobalt nutricline within the South Pacific gyre is deeper than in oligotrophic regions in the North and South Atlantic, cobalt involved in sustaining phytoplankton productivity in the gyre is heavily recycled and ultimately arrives from lateral transport of upwelled waters from the eastern margin. In contrast to large coastal inputs, atmospheric deposition and hydrothermal vents along the East Pacific Rise appear to be minor sources of cobalt. Overall, these results demonstrate that oxygen biogeochemistry exerts a strong influence on cobalt cycling.This work was funded by NSF awards OCE-1233733 to MAS, OCE-1232814 to BST, and OCE-1237011 to JAR

Law in other contexts: stand bravely brothers! a report from the law wars

This essay argues against the two pillars of current research on law and globalisation, from the perspective of legal theory and political philosophy: first, the distinction between ‘well-ordered’ and ‘not so well-ordered’ societies; second, the sociological model of the subject as pacified, fearful and isolated (to sum up, in harmony). It is argued that mainstream legal theory and political philosophy merely reflects the actual rules of the game of competition, dispute and conflict. In contrast, this essay takes sides with the anthropological and philosophical tradition that conceives the subject as antagonistic and in state of lack, profoundly concerned with the other, whom she imitates and whose standpoint she must be able to share if she is to make sense of the world. Furthermore, it is argued that transitivity or imitation lies at the very origin of conflict and dispute; lack and antagonism remain thus at the core of society, in spite of the surface appearance of harmony that characterises post-modern societies. Because of this, any general theory of law and society that wishes to be relevant at the time of globalisation must make the experience of antagonism and violence, motivated by imitation and envy, and its containment, its object of study. To do this, it must abandon the dualist conception of subjects and societies expressed in the distinction between ‘well-ordered’ (more violent) and ‘not-so-well-ordered’ (less violent) societies that has informed its investigation to this day, in order to declare in the most general terms a critique of violence from the standpoint of the victim, as of a piece with its demand for global social and political justice. Description from publisher website at: http://journals.cambridge.org/action/displayIssue?jid=IJC&volumeId=4&issueId=02&iid=243936

Elevated Trace Metal Content of Prokaryotic Communities Associated with Marine Oxygen Deficient Zones

Little is known about the trace metal content of marine prokaryotes, in part due to their co-occurrence with more abundant particulate phases in the upper ocean, such as phytoplankton and biogenic detritus, lithogenic minerals, and authigenic Mn and Fe oxyhydroxides. We attempt to isolate these biomass signals in particulate data from the US GEOTRACES Eastern Pacific Zonal Transect (cruise GP16) in the Eastern Tropical South Pacific (ETSP), which exhibited consistent maxima in P and other bioactive trace metals, and minima in particulate Mn, in the oxygen deficient zones (ODZs) of 13 stations. Nitrite maxima and nitrate deficits indicated the presence of denitrifying prokaryotic biomass within ETSP ODZs, and deep secondary fluorescence maxima at the upper ODZ boundaries of 10 stations also suggested the presence of low-light, autotrophic communities. ODZs were observed as far west as 99 degrees W, more than 2300 km from the South American coast, where eolian lithogenic and lateral/resuspended sedimentary inputs were negligible, presenting a unique opportunity to examine prokaryotic metal stoichiometries. ODZ particulate P maxima can rival gyre mixed layer biomass concentrations, are highly sensitive to oxygen, and are in excess of amounts scavengable by local Fe oxyhydroxides and acid-volatile sulfides. Even after correction for lithogenic and ferruginous-scavenged metals, ODZ P-maxima are often enriched in Cd, Co, Cu, Ni, V, and Zn, exhibiting particulate trace metal ratios to P that exceed mixed layer biomass ratios by factors of 2-9. ODZ prokaryotic communities may be largely hidden, TM-rich pools involved in the marine cycles of these bioactive trace metals