Chierici
Melissa
Chierici
Melissa
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ArticleLeads in Arctic pack ice enable early phytoplankton blooms below snow-covered sea ice(Nature Publishig Group, 2019-01-17) Assmy, Philipp ; Fernández-Méndez, Mar ; Duarte, Pedro ; Meyer, Amelie ; Randelhoff, Achim ; Mundy, Christopher J. ; Olsen, Lasse M. ; Kauko, Hanna Maria ; Bailey, Allison ; Chierici, Melissa ; Cohen, Lana ; Doulgeris, Anthony P. ; Ehn, Jens K. ; Fransson, Agneta ; Gerland, Sebastian ; Hop, Haakon ; Hudson, Stephen R. ; Hughes, Nick ; Itkin, Polona ; Johnsen, Geir ; King, Jennifer A. ; Koch, Boris P. ; Koenig, Zoe ; Kwasniewski, Slawomir ; Laney, Samuel R. ; Nicolaus, Marcel ; Pavlov, Alexey K. ; Polashenski, Christopher M. ; Provost, Christine ; Rösel, Anja ; Sandbu, Marthe ; Spreen, Gunnar ; Smedsrud, Lars H. ; Sundfjord, Arild ; Taskjelle, Torbjørn ; Tatarek, Agnieszka ; Wiktor, Jozef ; Wagner, Penelope M. ; Wold, Anette ; Steen, Harald ; Granskog, Mats A.The Arctic icescape is rapidly transforming from a thicker multiyear ice cover to a thinner and largely seasonal first-year ice cover with significant consequences for Arctic primary production. One critical challenge is to understand how productivity will change within the next decades. Recent studies have reported extensive phytoplankton blooms beneath ponded sea ice during summer, indicating that satellite-based Arctic annual primary production estimates may be significantly underestimated. Here we present a unique time-series of a phytoplankton spring bloom observed beneath snow-covered Arctic pack ice. The bloom, dominated by the haptophyte algae Phaeocystis pouchetii, caused near depletion of the surface nitrate inventory and a decline in dissolved inorganic carbon by 16 ± 6 g C m−2. Ocean circulation characteristics in the area indicated that the bloom developed in situ despite the snow-covered sea ice. Leads in the dynamic ice cover provided added sunlight necessary to initiate and sustain the bloom. Phytoplankton blooms beneath snow-covered ice might become more common and widespread in the future Arctic Ocean with frequent lead formation due to thinner and more dynamic sea ice despite projected increases in high-Arctic snowfall. This could alter productivity, marine food webs and carbon sequestration in the Arctic Ocean.
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ArticleShelled pteropods in peril : assessing vulnerability in a high CO2 ocean(Elsevier, 2017-04-09) Manno, Clara ; Bednarsek, Nina ; Tarling, Geraint A. ; Peck, Vicky L. ; Comeau, Steeve ; Adhikari, Deepak ; Bakker, Dorothee ; Bauerfeind, Eduard ; Bergan, Alexander J. ; Berning, Maria I. ; Buitenhuis, Erik T. ; Burridge, Alice K. ; Chierici, Melissa ; Flöter, Sebastian ; Fransson, Agneta ; Gardner, Jessie ; Howes, Ella L. ; Keul, Nina ; Kimoto, Katsunori ; Kohnert, Peter ; Lawson, Gareth L. ; Lischka, Silke ; Maas, Amy E. ; Mekkes, Lisette ; Oakes, Rosie L. ; Pebody, Corinne ; Peijnenburg, Katja T. C. A. ; Seifert, Miriam ; Skinner, Jennifer ; Thibodeau, Patricia S. ; Wall-Palmer, Deborah ; Ziveri, PatriziaThe impact of anthropogenic ocean acidification (OA) on marine ecosystems is a vital concern facing marine scientists and managers of ocean resources. Euthecosomatous pteropods (holoplanktonic gastropods) represent an excellent sentinel for indicating exposure to anthropogenic OA because of the sensitivity of their aragonite shells to the OA conditions less favorable for calcification. However, an integration of observations, experiments and modelling efforts is needed to make accurate predictions of how these organisms will respond to future changes to their environment. Our understanding of the underlying organismal biology and life history is far from complete and must be improved if we are to comprehend fully the responses of these organisms to the multitude of stressors in their environment beyond OA. This review considers the present state of research and understanding of euthecosomatous pteropod biology and ecology of these organisms and considers promising new laboratory methods, advances in instrumentation (such as molecular, trace elements, stable isotopes, palaeobiology alongside autonomous sampling platforms, CT scanning and high-quality video recording) and novel field-based approaches (i.e. studies of upwelling and CO2 vent regions) that may allow us to improve our predictive capacity of their vulnerability and/or resilience. In addition to playing a critical ecological and biogeochemical role, pteropods can offer a significant value as an early-indicator of anthropogenic OA. This role as a sentinel species should be developed further to consolidate their potential use within marine environmental management policy making.
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ArticleUncertainty sources for measurable ocean carbonate chemistry variables(Association for the Sciences of Limnology and Oceanography (ASLO), 2023-12-14) Carter, Brendan R. ; Sharp, Jonathan D. ; Dickson, Andrew G. ; Alvarez, Marta ; Fong, Michael B. ; Garcia-Ibanez, Maribel I. ; Woosley, Ryan J. ; Takeshita, Yuichiro ; Barbero, Leticia ; Byrne, Robert H. ; Cai, Wei-Jun ; Chierici, Melissa ; Clegg, Simon L. ; Easley, Regina A. ; Fassbender, Andrea J. ; Fleger, Kalla L. ; Li, Xinyu ; Martin-Mayor, Macarena ; Schockman, Katelyn M. ; Wang, Zhaohui AleckThe ocean carbonate system is critical to monitor because it plays a major role in regulating Earth's climate and marine ecosystems. It is monitored using a variety of measurements, and it is commonly understood that all components of seawater carbonate chemistry can be calculated when at least two carbonate system variables are measured. However, several recent studies have highlighted systematic discrepancies between calculated and directly measured carbonate chemistry variables and these discrepancies have large implications for efforts to measure and quantify the changing ocean carbon cycle. Given this, the Ocean Carbonate System Intercomparison Forum (OCSIF) was formed as a working group through the Ocean Carbon and Biogeochemistry program to coordinate and recommend research to quantify and/or reduce uncertainties and disagreements in measurable seawater carbonate system measurements and calculations, identify unknown or overlooked sources of these uncertainties, and provide recommendations for making progress on community efforts despite these uncertainties. With this paper we aim to (1) summarize recent progress toward quantifying and reducing carbonate system uncertainties; (2) advocate for research to further reduce and better quantify carbonate system measurement uncertainties; (3) present a small amount of new data, metadata, and analysis related to uncertainties in carbonate system measurements; and (4) restate and explain the rationales behind several OCSIF recommendations. We focus on open ocean carbonate chemistry, and caution that the considerations we discuss become further complicated in coastal, estuarine, and sedimentary environments.