Adminstration

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  • Article
    How the oceanographic community created a National Oceanographic Partnership Program
    (Oceanography Society, 2009-06) Watkins, James D. ; Schaff, Terrence R. ; Spinrad, Richard W.
    On this tenth anniversary of the National Oceanographic Partnership Program, and as our nation embarks on a broad set of critical societal initiatives, it is valuable to review the accomplishments of the program, and reflect on conceptual origins of the ocean partnership idea and the process by which the program was conceived and established.
  • Preprint
    A comparison of filtration rates among pelagic tunicates using kinematic measurements
    ( 2009-11) Sutherland, Kelly R. ; Madin, Laurence P.
    Salps have higher filtration rates than most other holoplankton, and are capable of packaging and exporting primary production from surface waters. A method of kinematic analysis was employed to accurately measure salp feeding rates. The data were then used to explain how diverse body morphologies and swimming motions among species and lifecycle stages influence salp feeding performance. We selected five species, representing a range of morphologies and swimming styles, and used digitized outlines from video frames to measure body-shape change during a pulse cycle. Time-varying body volume was then calculated from the digitized salp outlines to estimate the amount of fluid passing through the filtering mesh. This non-invasive method produced higher feeding rates than other methods and revealed that body volume, pulse frequency and degree of contraction are important factors for determining volume filtered. Each species possessed a unique combination of these three characteristics that resulted in comparable filtration (range: 0.44 - 15.33 ml s-1) and normalized filtration rates (range: 0.21 – 1.27 s-1) across species. The convergence of different species with diverse morphologies on similar normalized filtration suggests a tendency towards a flow optimum.
  • Preprint
    Filtration of submicrometer particles by pelagic tunicates
    ( 2010-07) Sutherland, Kelly R. ; Madin, Laurence P. ; Stocker, Roman
    Salps are common in oceanic waters and have higher per individual filtration rates than any other zooplankton filter feeder. Though salps are centimeters in length, feeding via particle capture occurs on a fine, mucous mesh (fiber diameter d ~ 0.1 μm) at low velocity (U = 1.6 ± 0.6 cm s-1, mean ± SD) and is thus a low-Reynolds number (Re ~ 10-3) process. In contrast to the current view that particle encounter is dictated by simple sieving of particles larger than the mesh spacing, a low-Re mathematical model of encounter rates by the salp feeding apparatus for realistic oceanic particle size distributions shows that submicron particles, due to their higher abundances, are encountered at higher rates (particles per time) than larger particles. Data from feeding experiments with 0.5, 1 and 3 μm diameter polystyrene spheres corroborate these results. Though particles larger than 1 μm (e.g. flagellates, small diatoms) represent a larger carbon pool, smaller particles in the 0.1–1 μm range (e.g. bacteria, Prochlorococcus) may be more quickly digestible because they present more surface area, and we find that particles smaller than the mesh size (1.4 μm) can fully satisfy salp energetic needs. Furthermore, by packaging submicrometer particles into rapidly sinking fecal pellets, pelagic tunicates can substantially change particle size spectra and increase downward fluxes in the ocean.
  • Preprint
    The remarkable squidworm is an example of discoveries that await in deep-pelagic habitats
    ( 2010-11) Osborn, Karen J. ; Madin, Laurence P. ; Rouse, Greg W.
    An intriguing new annelid, Teuthidodrilus samae (Annelida, Cirratuliformia) gen. and sp. nov., was observed and collected during deep water column exploration of the western Celebes Sea. The Celebes Sea is a deep pocket basin, effectively isolated from surrounding deep water, and is part of the Coral Triangle, a focal area for conservation because of its high diversity and unique geological history. Collected specimens reached 94 mm in length and possessed 10 anterior appendages that were as long or longer than the body. Two characters distinguish T. samae from other polychaetes: notochaetae forming broad, concavo-convex paddles, and six pairs of free-standing, oppositely branched nuchal organs. Phylogenetic analysis of five genes and a 29 character morphological matrix showed that T. samae is an acrocirrid (primarily benthic polychaetes) belonging to the morphologically diverse swimming clade. Pelagic animals within primarily benthic clades are of particular interest in evolutionary biology, because their adaptations to life in the water column inform us of the evolutionary possibilities and constraints within the clade and indirectly of the selective pressures at work in this unfamiliar habitat. This new genus illustrates how much we have to learn about even the large, abundant inhabitants of deep-pelagic communities.
  • Article
    Study of marine ecosystems and biogeochemistry now and in the future : examples of the unique contributions from space
    (Oceanography Society, 2010-12) Yoder, James A. ; Doney, Scott C. ; Siegel, David A. ; Wilson, Cara
    Ocean color remote sensing has profoundly influenced how oceanographers think about marine ecosystems and their variability in space and time. Satellite ocean color radiometry (OCR) provides a unique perspective for studying the processes regulating marine ecosystems and biogeochemistry at scales difficult to study with ships and moorings. Satellite OCR is especially useful when supported by other in situ and space observations. In this review, we highlight three areas related to marine ecosystems and biogeochemical processes to which satellite observations have made important and unique contributions: understanding the responses of ocean ecosystems to physical processes operating at meso- to global scales, coupled physical-ecosystem-biogeochemical modeling, and marine living resource management.
  • Preprint
    Impact of phytoplankton community size on a linked global ocean optical and ecosystem model
    ( 2011-01) Mouw, Colleen B. ; Yoder, James A. ; Doney, Scott C.
    We isolated the effect phytoplankton cell size has on varying remote sensing reflectance spectra (Rrs(λ)) in the presence of optically active constituents by using optical and radiative transfer models linked in an offline diagnostic calculation to a global biogeochemical/ecosystem/circulation model with explicit phytoplankton size classes. Two case studies were carried out, each with several scenarios to isolate the effects of chlorophyll concentration, phytoplankton cell size, and size-varying phytoplankton absorption on Rrs(λ). The goal of the study was to determine the relative contribution of phytoplankton cell size and chlorophyll to overall Rrs(λ) and to understand where a standard band ratio algorithm (OC4) may under/overestimate chlorophyll due to Rrs(λ) being significantly affected by phytoplankton size. Phytoplankton cell size was found to contribute secondarily to Rrs(λ) variability and to amplify or dampen the seasonal cycle in Rrs(λ), driven by chlorophyll. Size and chlorophyll were found to change in phase at low to mid-latitudes, but were anti-correlated or poorly correlated at high latitudes. Phytoplankton size effects increased model calculated Rrs(443) in the subtropical ocean during local spring through early fall months in both hemispheres and decreased Rrs(443) in the Northern Hemisphere high latitude regions during local summer to fall months. This study attempts to tease apart when/where variability about the OC4 relationship may be associated with cell size variability. The OC4 algorithm may underestimate [Chl] when the fraction of microplankton is elevated, which occurs in the model simulations during local spring/summer months at high latitudes in both hemispheres.
  • Article
    Questioning the rise of gelatinous zooplankton in the world's oceans
    (American Institute of Biological Sciences, 2012-02) Condon, Robert H. ; Graham, William M. ; Duarte, Carlos M. ; Pitt, Kylie A. ; Lucas, Cathy H. ; Haddock, Steven H. D. ; Sutherland, Kelly R. ; Robinson, Kelly L. ; Dawson, Michael N. ; Decker, Mary Beth ; Mills, Claudia E. ; Purcell, Jennifer E. ; Malej, Alenka ; Mianzan, Hermes ; Uye, Shin-Ichi ; Gelcich, Stefan ; Madin, Laurence P.
    During the past several decades, high numbers of gelatinous Zooplankton species have been reported in many estuarine and coastal ecosystems. Coupled with media-driven public perception, a paradigm has evolved in which the global ocean ecosystems are thought to he heading toward being dominated by “nuisance” jellyfish. We question this current paradigm by presenting a broad overview of gelatinous Zooplankton in a historical context to develop the hypothesis that population changes reflect the human-mediated alteration of global ocean ecosystems. To this end, we synthesize information related to the evolutionary context of contemporary gelatinous Zooplankton blooms, the human frame of reference for changes in gelatinous Zooplankton populations, and whether sufficient data are available to have established the paradigm. We conclude that the current paradigm in which it is believed that there has been a global increase in gelatinous Zooplankton is unsubstantiated, and we develop a strategy for addressing the critical questions about long-term, human-related changes in the sea as they relate to gelatinous Zooplankton blooms.
  • Article
    Is global ocean sprawl a cause of jellyfish blooms?
    (Ecological Society of America, 2012-09-07) Duarte, Carlos M. ; Pitt, Kylie A. ; Lucas, Cathy H. ; Purcell, Jennifer E. ; Uye, Shin-Ichi ; Robinson, Kelly L. ; Brotz, Lucas ; Decker, Mary Beth ; Sutherland, Kelly R. ; Malej, Alenka ; Madin, Laurence P. ; Mianzan, Hermes ; Gili, Josep-Maria ; Fuentes, Veronica ; Atienza, Dacha ; Pages, Francesc ; Breitburg, Denise L. ; Malek, Jennafer ; Graham, William M. ; Condon, Robert H.
    Jellyfish (Cnidaria, Scyphozoa) blooms appear to be increasing in both intensity and frequency in many coastal areas worldwide, due to multiple hypothesized anthropogenic stressors. Here, we propose that the proliferation of artificial structures – associated with (1) the exponential growth in shipping, aquaculture, and other coastal industries, and (2) coastal protection (collectively, “ocean sprawl”) – provides habitat for jellyfish polyps and may be an important driver of the global increase in jellyfish blooms. However, the habitat of the benthic polyps that commonly result in coastal jellyfish blooms has remained elusive, limiting our understanding of the drivers of these blooms. Support for the hypothesized role of ocean sprawl in promoting jellyfish blooms is provided by observations and experimental evidence demonstrating that jellyfish larvae settle in large numbers on artificial structures in coastal waters and develop into dense concentrations of jellyfish-producing polyps.
  • Article
    Regional to global assessments of phytoplankton dynamics from the SeaWiFS mission
    (Elsevier, 2013-04-20) Siegel, David A. ; Behrenfeld, Michael J. ; Maritorena, S. ; McClain, Charles R. ; Antoine, David ; Bailey, S. W. ; Bontempi, P. S. ; Boss, Emmanuel S. ; Dierssen, Heidi M. ; Doney, Scott C. ; Eplee, R. E. ; Evans, R. H. ; Feldman, G. C. ; Fields, Erik ; Franz, Bryan A. ; Kuring, N. A. ; Mengelt, C. ; Nelson, Norman B. ; Patt, F. S. ; Robinson, W. D. ; Sarmiento, Jorge L. ; Swan, C. M. ; Werdell, P. J. ; Westberry, Toby K. ; Wilding, J. G. ; Yoder, James A.
    Photosynthetic production of organic matter by microscopic oceanic phytoplankton fuels ocean ecosystems and contributes roughly half of the Earth's net primary production. For 13 years, the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) mission provided the first consistent, synoptic observations of global ocean ecosystems. Changes in the surface chlorophyll concentration, the primary biological property retrieved from SeaWiFS, have traditionally been used as a metric for phytoplankton abundance and its distribution largely reflects patterns in vertical nutrient transport. On regional to global scales, chlorophyll concentrations covary with sea surface temperature (SST) because SST changes reflect light and nutrient conditions. However, the ocean may be too complex to be well characterized using a single index such as the chlorophyll concentration. A semi-analytical bio-optical algorithm is used to help interpret regional to global SeaWiFS chlorophyll observations from using three independent, well-validated ocean color data products; the chlorophyll a concentration, absorption by CDM and particulate backscattering. First, we show that observed long-term, global-scale trends in standard chlorophyll retrievals are likely compromised by coincident changes in CDM. Second, we partition the chlorophyll signal into a component due to phytoplankton biomass changes and a component caused by physiological adjustments in intracellular chlorophyll concentrations to changes in mixed layer light levels. We show that biomass changes dominate chlorophyll signals for the high latitude seas and where persistent vertical upwelling is known to occur, while physiological processes dominate chlorophyll variability over much of the tropical and subtropical oceans. The SeaWiFS data set demonstrates complexity in the interpretation of changes in regional to global phytoplankton distributions and illustrates limitations for the assessment of phytoplankton dynamics using chlorophyll retrievals alone.
  • Article
    Gravity wave characteristics in the mesopause region revealed from OH airglow imager observations over Northern Colorado
    (John Wiley & Sons, 2014-01-31) Tang, Yihuan ; Dou, Xiankang ; Li, Tao ; Nakamura, Takuji ; Xue, Xianghui ; Huang, Can ; Manson, Alan ; Meek, Chris ; Thorsen, Denise ; Avery, Susan K.
    Using 5 years of all-sky OH airglow imager data over Yucca Ridge Field Station, CO (40.7°N, 104.9°W), from September 2003 to September 2008, we extract and deduce quasi-monochromatic gravity wave (GW) characteristics in the mesopause region. The intrinsic periods are clustered between approximately 4 and 10 min, and many of them are unstable and evanescent. GW occurrence frequency exhibits a clear semiannual variation with equinoctial minima, which is likely related to the seasonal variation of background wind. The anomalous propagation direction in January 2006, with strong southward before major warming starting in 21 January and weak southward propagation afterward, was most likely affected by stratospheric sudden warming. The momentum fluxes show strongly anticorrelated with the tides, with ~180° out of phase in the zonal component. While in the meridional component, the easterly maximum occurred approximately 2–6 h after maximum easterly tidal wind. However, the anticorrelations are both weakest during the summer. The dissipating and breaking of small-scale and high-frequency GW's components could have a potential impact on the general circulation in the mesopause region.
  • Article
    Linking human well-being and jellyfish : ecosystem services, impacts, and societal responses
    (Ecological Society of America, 2014-11) Graham, William M. ; Gelcich, Stefan ; Robinson, Kelly L. ; Duarte, Carlos M. ; Brotz, Lucas ; Purcell, Jennifer E. ; Madin, Laurence P. ; Mianzan, Hermes ; Sutherland, Kelly R. ; Uye, Shin-Ichi ; Pitt, Kylie A. ; Lucas, Cathy H. ; Bogeberg, Molly ; Brodeur, Richard D. ; Condon, Robert H.
    Jellyfish are usually perceived as harmful to humans and are seen as “pests”. This negative perception has hindered knowledge regarding their value in terms of ecosystem services. As humans increasingly modify and interact with coastal ecosystems, it is important to evaluate the benefits and costs of jellyfish, given that jellyfish bloom size, frequency, duration, and extent are apparently increasing in some regions of the world. Here we explore those benefits and costs as categorized by regulating, supporting, cultural, and provisioning ecosystem services. A geographical perspective of human vulnerability to jellyfish over four categories of human well-being (health care, food, energy, and freshwater production) is also discussed in the context of thresholds and trade-offs to enable social adaptation. Whereas beneficial services provided by jellyfish likely scale linearly with biomass (perhaps peaking at a saturation point), non-linear thresholds exist for negative impacts to ecosystem services. We suggest that costly adaptive strategies will outpace the beneficial services if jellyfish populations continue to increase in the future.
  • Preprint
    Global Ocean Summit : a forum for institutional coordination of global ocean observations
    ( 2014-11) Cai, Wenju ; Avery, Susan K. ; Leinen, Margaret S. ; Lee, Kenneth ; Lin, Xiaopei ; Visbeck, Martin
    A sustainable global ocean observation system requires timely implementation of a global ocean observation framework. The recent Qingdao Global Ocean Summit offers an effective mechanism for a coherent institutional response to emerging scientific and societal drivers, and for promoting the capacity building in developing economies that is essential for increasing the value and broadening the funding base of the observation system.
  • Working Paper
    A modern coastal ocean observing system using data from advanced satellite and in situ sensors – an example
    (NSF/Ocean Research Coordination Network, 2015-06-01) Yoder, James A. ; Davis, Curtiss O. ; Dierssen, Heidi M. ; Muller-Karger, Frank E. ; Mahadevan, Amala ; Pearlman, Jay ; Sosik, Heidi M.
    This report is intended to illustrate and provide recommendations for how ocean observing systems of the next decade could focus on coastal environments using combined satellite and in situ measurements. Until recently, space-based observations have had surface footprints typically spanning hundreds of meters to kilometers. These provide excellent synoptic views for a wide variety of ocean characteristics. In situ observations are instead generally point or linear measurements. The interrelation between space-based and in-situ observations can be challenging. Both are necessary and as sensors and platforms evolve during the next decade, the trend to facilitate interfacing space and in-situ observations must continue and be expanded. In this report, we use coastal observation and analyses to illustrate an observing system concept that combines in situ and satellite observing technologies with numerical models to quantify subseasonal time scale transport of freshwater and its constituents from terrestrial water storage bodies across and along continental shelves, as well as the impacts on some key biological/biogeochemical properties of coastal waters.
  • Article
    A moving target : matching graduate education with available careers for ocean scientists
    (The Oceanography Society, 2016-03) Briscoe, Melbourne G. ; Glickson, Deborah A. ; Roberts, Susan ; Spinrad, Richard W. ; Yoder, James A.
    The objective of this paper is to look at past assessments and available data to examine the match (or mismatch) between university curricula and programs available to graduate students in the ocean sciences and the career possibilities available to those students. We conclude there is a need for fundamental change in how we educate graduate students in the ocean sciences. The change should accommodate the interests of students as well as the needs of a changing society; the change should not be constrained by the traditions or resource challenges of the graduate institutions themselves. The limited data we have been able to obtain from schools and employers are consistent with this view: desirable careers for ocean scientists are moving rapidly toward interdisciplinary, collaborative, societally relevant activities, away from traditional academic-research/professorial jobs, but the training available to the students is not keeping pace. We offer some suggestions to mitigate the mismatch. Most importantly, although anecdotes and “gut feelings” abound, the quantitative data backing our conclusions and suggestions are very sparse and barely compelling; we urge better data collection to support curricular revision, perhaps with the involvement of professional societies.
  • Article
    Designing the climate observing system of the future
    (John Wiley & Sons, 2018-01-23) Weatherhead, Elizabeth C. ; Wielicki, Bruce A. ; Ramaswamy, Venkatachalam ; Abbott, Mark ; Ackerman, Thomas P. ; Atlas, Robert ; Brasseur, Guy ; Bruhwiler, Lori ; Busalacchi, Antonio J. ; Butler, James H. ; Clack, Christopher T. M. ; Cooke, Roger ; Cucurull, Lidia ; Davis, Sean M. ; English, Jason M. ; Fahey, David W. ; Fine, Steven S. ; Lazo, Jeffrey K. ; Liang, Shunlin ; Loeb, Norman G. ; Rignot, Eric ; Soden, Brian ; Stanitski, Diane ; Stephens, Graeme ; Tapley, Byron D. ; Thompson, Anne M. ; Trenberth, Kevin E. ; Wuebbles, Donald
    Climate observations are needed to address a large range of important societal issues including sea level rise, droughts, floods, extreme heat events, food security, and freshwater availability in the coming decades. Past, targeted investments in specific climate questions have resulted in tremendous improvements in issues important to human health, security, and infrastructure. However, the current climate observing system was not planned in a comprehensive, focused manner required to adequately address the full range of climate needs. A potential approach to planning the observing system of the future is presented in this article. First, this article proposes that priority be given to the most critical needs as identified within the World Climate Research Program as Grand Challenges. These currently include seven important topics: melting ice and global consequences; clouds, circulation and climate sensitivity; carbon feedbacks in the climate system; understanding and predicting weather and climate extremes; water for the food baskets of the world; regional sea-level change and coastal impacts; and near-term climate prediction. For each Grand Challenge, observations are needed for long-term monitoring, process studies and forecasting capabilities. Second, objective evaluations of proposed observing systems, including satellites, ground-based and in situ observations as well as potentially new, unidentified observational approaches, can quantify the ability to address these climate priorities. And third, investments in effective climate observations will be economically important as they will offer a magnified return on investment that justifies a far greater development of observations to serve society's needs.
  • Working Paper
    Improving communication of climate change science to public audiences : early career ocean scientists and science interpreters engage with social scientists
    ( 2018-03-27) Yoder, James
    This manuscript describes a qualitative study based on the results of interviews with early career scientists (graduate students and postdocs) who participated as “science fellows” along with science interpreters for training led by social scientists as to how to discuss ocean and climate change issues with general audiences. Based on the interviews, the science fellows were generally enthusiastic and effective participants in the program, and the training gave them more confidence for discussing the effects of climate change on the ocean. In addition, and of equal importance, the science fellows generally believed that the training helped them organize their written and oral presentations of their own science for their professional colleagues and is a lasting benefit to their career development.
  • Article
    Unanticipated benefit of an outreach program
    (The Oceanography Society, 2018-09-15) Yoder, James
    The National Science Foundation supported six projects that comprised the Climate Change Education Partnership, including the National Net-work for Ocean and Climate Change Interpretation (NNOCCI) for which the Woods Hole Oceanographic Institution (WHOI) is the science partner. The New England Aquarium leads NNOCCI, and the network also includes informal science educators, social and cognitive scientists, and evaluators. The partners work together to improve public awareness of climate change and its impact on the ocean (Spitzer, 2014; Fraser et al., 2015; Anderson, 2016).
  • Article
    Evaluating knowledge to support climate action: A framework for sustained assessment. report of an independent advisory committee on applied climate assessment.
    (American Meteorological Society, 2019-05-21) Moss, Richard H. ; Avery, Susan K. ; Baja, Kristin ; Burkett, Maxine ; Chischilly, Ann Marie ; Dell, Janet ; Fleming, P. A. ; Geil, Kerrie L. ; Jacobs, Katharine L. ; Jones, Alan H. ; Knowlton, Kim ; Koh, Jay ; Lemos, Maria Carmen ; Melillo, Jerry M. ; Pandya, Rajul ; Richmond, Terese ; Scarlett, Lynn ; Snyder, Jared ; Stults, Melissa ; Waple, Anne ; Whitehead, Jessica ; Zarrilli, Daniel ; Ayyub, Bilal M. ; Fox, James ; Ganguly, Auroop ; Joppa, Lucas ; Julius, Susan ; Kirshen, Paul ; Kreutter, Rebecca ; McGovern, Amy ; Meyer, Ryan ; Neumann, James ; Solecki, William ; Smith, Joel ; Tissot, Philippe ; Yohe, Gary ; Zimmerman, Rae
    As states, cities, tribes, and private interests cope with climate damages and seek to increase preparedness and resilience, they will need to navigate myriad choices and options available to them. Making these choices in ways that identify pathways for climate action that support their development objectives will require constructive public dialogue, community participation, and flexible and ongoing access to science- and experience-based knowledge. In 2016, a Federal Advisory Committee (FAC) was convened to recommend how to conduct a sustained National Climate Assessment (NCA) to increase the relevance and usability of assessments for informing action. The FAC was disbanded in 2017, but members and additional experts reconvened to complete the report that is presented here. A key recommendation is establishing a new nonfederal “climate assessment consortium” to increase the role of state/local/tribal government and civil society in assessments. The expanded process would 1) focus on applied problems faced by practitioners, 2) organize sustained partnerships for collaborative learning across similar projects and case studies to identify effective tested practices, and 3) assess and improve knowledge-based methods for project implementation. Specific recommendations include evaluating climate models and data using user-defined metrics; improving benefit–cost assessment and supporting decision-making under uncertainty; and accelerating application of tools and methods such as citizen science, artificial intelligence, indicators, and geospatial analysis. The recommendations are the result of broad consultation and present an ambitious agenda for federal agencies, state/local/tribal jurisdictions, universities and the research sector, professional associations, nongovernmental and community-based organizations, and private-sector firms.
  • Article
    Pacific-wide pH snapshots reveal that high coral cover correlates with low, but variable pH
    (Rosenstiel School of Marine and Atmospheric Science, 2020-03-08) Manzello, Derek P. ; Enochs, Ian C. ; Carlton, Renée ; Bruckner, Andrew ; Kolodziej, Graham ; Dempsey, Alexandra ; Renaud, Philip
    Ocean acidification (OA) is impairing the construction of coral reefs while simultaneously accelerating their breakdown. The metabolism of different reef organism assemblages alters seawater pH in different ways, possibly buffering or exacerbating OA impacts. In spite of this, field data relating benthic community structure and seawater pH are sparse. We collected pH time-series data snapshots at 10 m depth from 28 different reefs (n = 13 lagoon, n = 15 fore reef) across 22 Pacific islands, spanning 31° latitude and 90° longitude. Coincident with all deployments, we measured percent cover of the benthic community. On fore reefs, high coral cover (CC) negatively correlated with mean and minimum pH, but positively correlated with pH variability. Conversely, pH minima were positively correlated to coverage of coralline and turf algae. Benthic cover did not correlate with pH in lagoonal reefs. From 0% to 100% CC, mean pH and aragonite saturation state (Ωarag) declined −0.081 and −0.51, respectively, while declines in minimum values were greater (Δmin pH = −0.164, Δmin Ωarag = −0.96). Based upon previously published relationships, the mean pH decline from 0% to 100% CC would depress coral calcification 7.7%–18.0% and increase biologically-mediated dissolution 13.5%–27.9%, with pH minima depressing dark coral calcification 14.4%–35.2% and increasing biologically-mediated dissolution 31.0%–62.2%. This spatially expansive dataset provides evidence that coral reefs with the highest coral cover may experience the lowest and most extreme pH values with OA.
  • Article
    Relationship between individual chamber and whole shell Mg/Ca ratios in Trilobatus sacculifer and implications for individual foraminifera palaeoceanographic reconstructions
    (Nature Research, 2021-01-11) Rustic, Gerald T. ; Polissar, Pratigya J. ; Ravelo, Ana Christina ; de Menocal, Peter B.
    Precisely targeted measurements of trace elements using laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) reveal inter-chamber heterogeneities in specimens of the planktic foraminifer Trilobatus (Globigerinoides) sacculifer. We find that Mg/Ca ratios in the final growth chamber are generally lower compared to previous growth chambers, but final chamber Mg/Ca is elevated in one of thirteen sample intervals. Differences in distributions of Mg/Ca values from separate growth chambers are observed, occurring most often at lower Mg/Ca values, suggesting that single-chamber measurements may not be reflective of the specimen’s integrated Mg/Ca. We compared LA-ICPMS Mg/Ca values to paired, same-individual Mg/Ca measured via inductively coupled plasma optical emission spectrometry (ICP-OES) to assess their correspondence. Paired LA-ICPMS and ICP-OES Mg/Ca show a maximum correlation coefficient of R = 0.92 (p < 0.05) achieved by applying a weighted average of the last and penultimate growth chambers. Population distributions of paired Mg/Ca values are identical under this weighting. These findings demonstrate that multi-chamber LA-ICPMS measurements can approximate entire specimen Mg/Ca, and is thus representative of the integrated conditions experienced during the specimen’s lifespan. This correspondence between LA-ICPMS and ICP-OES data links these methods and demonstrates that both generate Mg/Ca values suitable for individual foraminifera palaeoceanographic reconstructions.