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Kim J, La HS, Kim JH, Jo N, Lee J, Kim BK, Son W, Kim K, Jang HK, Park S, Yoo H, Kim J, Park J, Ahn SH, Lee SH. Spatio-temporal variations in organic carbon composition driven by two different major phytoplankton communities in the Ross Sea, Antarctica. Sci Total Environ 2023; 891:164666. [PMID: 37286011 DOI: 10.1016/j.scitotenv.2023.164666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/30/2023] [Accepted: 06/02/2023] [Indexed: 06/09/2023]
Abstract
The compositions of organic carbon could be important in determining biological carbon pump efficiency. However, little information on them in relation to each algal assemblage is currently available in the Ross Sea. Here, we investigated the seasonal variations in organic carbon composition and the relative abundance of each organic carbon, including particulate organic carbon (POC), dissolved organic carbon (DOC), and transparent exopolymer particles (TEPs), characterized by different algal groups in the Ross Sea. The average POC and DOC contributions to the total organic carbon (TOC = POC + DOC) were 13.8 ± 3.7 % and 86.2 ± 3.7 % in mid-January 2019 and 20.9 ± 4.1 % and 79.1 ± 4.1 % in February-March 2018, respectively. The carbon content of TEP (TEP-C) contributed 19.6 ± 11.7 % and 4.6 ± 7.0 % of POC and TOC in mid-January and 36.2 ± 14.8 % and 9.0 ± 6.7 % in February-March, respectively. We found that the organic carbon compositions were affected by seasonal variations in the phytoplankton bloom phase, physical characteristics, and phytoplankton community structure. DOC concentrations and contributions to the TOC increased as phytoplankton cells became senescent in mid-January and decreased in February-March when phytoplankton were relatively active. From February-March, the deepened mixed layer depth encouraged TEP formation, subsequently increasing the TEP contributions. Regardless of the sampling season, all organic carbon concentrations per unit Chl-a were significantly higher in P. antarctica-abundant groups. The DOC contributions to the TOC were correspondingly higher at the P. antarctica-abundant stations in mid-January, which indicates that P. antarctica could be also important in the DOC contributions in the Ross Sea. The rapid alteration in environmental characteristics and phytoplankton community structures in the Ross Sea due to climate change could affect the organic carbon pool at the euphotic layer which consequently could determine the efficiency of the biological pump.
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Affiliation(s)
- Jaehong Kim
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Hyoung Sul La
- Division of Ocean Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Jeong-Hoon Kim
- Division of Life Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Naeun Jo
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Junbeom Lee
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Bo Kyung Kim
- Division of Ocean Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Wuju Son
- Division of Ocean Sciences, Korea Polar Research Institute, Incheon, South Korea; Department of Polar Science, University of Science and Technology, Daejeon, South Korea
| | - Kwanwoo Kim
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Hyo-Keun Jang
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Sanghoon Park
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Hyeju Yoo
- Division of Ocean Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - Jaesoon Kim
- Department of Oceanography, Pusan National University, Busan, South Korea
| | - Jisoo Park
- Division of Ocean Sciences, Korea Polar Research Institute, Incheon, South Korea
| | - So Hyun Ahn
- Horn Point Laboratory, University of Maryland Center for Environmental Science, Cambridge, USA
| | - Sang Heon Lee
- Department of Oceanography, Pusan National University, Busan, South Korea.
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Sierpinski SFD, Baquer LML, Martins CC, Grassi MT. Exploratory evaluation of iron and its speciation in surface waters of Admiralty Bay, King George Island, Antarctica. AN ACAD BRAS CIENC 2023; 95:e20211520. [PMID: 37585980 DOI: 10.1590/0001-3765202320211520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 06/19/2022] [Indexed: 08/18/2023] Open
Abstract
The determination of dissolved iron concentrations and speciation was conducted for the first time in surface seawater coastline samples collected during the austral summer of 2020 in Admiralty Bay, King George Island, Antarctica. The technique of competitive ligand exchange/adsorptive cathodic stripping voltammetry with 2,3-dihydroxynaphthalene as the competing ligand was evaluated, showing a sensitivity between 14.25 and 21.05 nA nmol L-1 min-1, with an LOD of 14 pmol L-1 and a mean blank contribution of 0.248 nmol L-1. Physicochemical parameters such as pH (7.85 ± 0.2), salinity (32.7 ± 0.8) and dissolved oxygen (51.3 ± 26.6%) were compatible with those of the literature; however, the average temperature (4.2 ± 0.8 °C) was higher, possibly as a reflection of global warming. The dissolved iron mean value was 18.9 ± 6.1 nmol L-1, with a total ligand concentration of 23.6 ± 12.2 nmol L-1 and a conditional stability complex constant of 12.2 ± 0.2, indicating humic substances as possible ligands. On average, the calculated free iron concentrations were 0.7 ± 0.3 pmol L-1. Relatively high concentrations of iron indicate a possible local source of Fe, likely predominantly from upwelling sediments and secondarily from ice-melting waters, which does not limit the growth of the phytoplankton.
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Affiliation(s)
- Sheisa F D Sierpinski
- Universidade Federal do Paraná, Departamento de Química, Av. Francisco H. dos Santos, 100, Caixa Postal 19032, 81531-980 Curitiba, PR, Brazil
| | - Luis Miguel Laglera Baquer
- Universidad de las Islas Baleares, FI-TRACE, Departamento de Química, Palma, Islas Baleares, 07122, España
| | - César C Martins
- Universidade Federal do Paraná, Centro de Estudos do Mar, Av. Beira Mar, s/n, Caixa Postal 61, 83255-976 Pontal do Paraná, PR, Brazil
| | - Marco Tadeu Grassi
- Universidade Federal do Paraná, Departamento de Química, Av. Francisco H. dos Santos, 100, Caixa Postal 19032, 81531-980 Curitiba, PR, Brazil
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Kwon YS, La HS, Kang HW, Park J. A regional-scale approach for modeling primary production and biogenic silica export in the Southern Ocean. Environ Res 2023; 217:114811. [PMID: 36414105 DOI: 10.1016/j.envres.2022.114811] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 11/09/2022] [Accepted: 11/12/2022] [Indexed: 06/16/2023]
Abstract
Persistent uncertainties in the representations of net primary production (NPP) and silicate in the Southern Ocean have been noted in recent assessments ofthe ocean biogeochemical components of Earth system models (ESMs). Consequently, more mechanistic studies at the regional scale are required. To reduce these uncertainties, we applied a one-dimensional (1D) marine ecosystem model to different bioregions in the Southern Ocean: the Polar Frontal Zone in the Pacific sector, the seasonal sea ice zone in the northwestern Ross Sea, and the inner shelf of Terra Nova Bay. To make the existing ecosystem model applicable to the Southern Ocean, we modified the phytoplankton physiology (stoichiometry depending on species) and the silicate cycle (dissolution rate of biogenic silica (BSi) depending on latitude) in the model. We quantified and compared seasonal variations in several limitation factors of NPP, namely, iron, irradiance, silicate and temperature, in the three regions. The simulation results showed that dissolved iron plays the most significant role in determining the magnitude of NPP and the phytoplankton community structure during summer. Additionally, the modified model successfully reproduced the vertical flux of BSi and particulate organic carbon (POC). The POC export efficiency was high in the inner shelf zone, which had high levels of iron concentration, NPP, and Phaeocystis biomass. In contrast, BSi export occurred most efficiently in the Polar Frontal Zone, where diatoms are dominant, the BSi dissolution rate is low, and NPP is extremely low. Our results from the integrated mechanistic framework at the regional scale demonstrate which specific processes should be urgently included in ESMs for better representation of the biogeochemical dynamics in the Southern Ocean.
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Affiliation(s)
- Young Shin Kwon
- Korea Institute of Ocean Science and Technology, Busan, Republic of Korea; Korea Polar Research Institute, Incheon, Republic of Korea
| | - Hyoung Sul La
- Korea Polar Research Institute, Incheon, Republic of Korea; University of Science and Technology, Daejeon, Republic of Korea.
| | - Hyoun-Woo Kang
- Korea Institute of Ocean Science and Technology, Busan, Republic of Korea
| | - Jisoo Park
- Korea Polar Research Institute, Incheon, Republic of Korea
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Piontek J, Meeske C, Hassenrück C, Engel A, Jürgens K. Organic matter availability drives the spatial variation in the community composition and activity of Antarctic marine bacterioplankton. Environ Microbiol 2022; 24:4030-4048. [PMID: 35656758 DOI: 10.1111/1462-2920.16087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 05/27/2022] [Indexed: 11/30/2022]
Abstract
Carbon cycling by Antarctic microbial plankton is poorly understood but it plays a major role in CO2 sequestration in the Southern Ocean. We investigated the summer bacterioplankton community in the largely understudied Weddell Sea, applying Illumina amplicon sequencing, measurements of bacterial production and chemical analyses of organic matter. The results revealed that the patchy distribution of productive coastal polynyas and less productive, mostly ice-covered sites was the major driver of the spatial changes in the taxonomic composition and activity of bacterioplankton. Gradients in organic matter availability induced by phytoplankton blooms were reflected in the concentrations and composition of dissolved carbohydrates and proteins. Bacterial production at bloom stations was, on average, 2.7 times higher than at less productive sites. Abundant bloom-responsive lineages were predominately affiliated with ubiquitous marine taxa, including Polaribacter, Yoonia-Loktanella, Sulfitobacter, the SAR92 clade, and Ulvibacter, suggesting a widespread genetic potential for adaptation to sub-zero seawater temperatures. A co-occurrence network analysis showed that dominant taxa at stations with low phytoplankton productivity were highly connected, indicating beneficial interactions. Overall, our study demonstrates that heterotrophic bacterial communities along Weddell Sea ice shelves were primarily constrained by the availability of labile organic matter rather than low seawater temperature. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Judith Piontek
- Leibniz Institute for Baltic Sea Research Warnemünde, Germany
| | | | | | - Anja Engel
- GEOMAR Helmholtz Centre for Ocean Research Kiel, Germany
| | - Klaus Jürgens
- Leibniz Institute for Baltic Sea Research Warnemünde, Germany
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Trefault N, De la Iglesia R, Moreno-Pino M, Lopes Dos Santos A, Gérikas Ribeiro C, Parada-Pozo G, Cristi A, Marie D, Vaulot D. Annual phytoplankton dynamics in coastal waters from Fildes Bay, Western Antarctic Peninsula. Sci Rep 2021; 11:1368. [PMID: 33446791 DOI: 10.1038/s41598-020-80568-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 12/22/2020] [Indexed: 01/04/2023] Open
Abstract
Year-round reports of phytoplankton dynamics in the West Antarctic Peninsula are rare and mainly limited to microscopy and/or pigment-based studies. We analyzed the phytoplankton community from coastal waters of Fildes Bay in the West Antarctic Peninsula between January 2014 and 2015 using metabarcoding of the nuclear and plastidial 18/16S rRNA gene from both size-fractionated and flow cytometry sorted samples. Overall 14 classes of photosynthetic eukaryotes were present in our samples with the following dominating: Bacillariophyta (diatoms), Pelagophyceae and Dictyochophyceae for division Ochrophyta, Mamiellophyceae and Pyramimonadophyceae for division Chlorophyta, Haptophyta and Cryptophyta. Each metabarcoding approach yielded a different image of the phytoplankton community with for example Prymnesiophyceae more prevalent in plastidial metabarcodes and Mamiellophyceae in nuclear ones. Diatoms were dominant in the larger size fractions and during summer, while Prymnesiophyceae and Cryptophyceae were dominant in colder seasons. Pelagophyceae were particularly abundant towards the end of autumn (May). In addition of Micromonas polaris and Micromonas sp. clade B3, both previously reported in Arctic waters, we detected a new Micromonas 18S rRNA sequence signature, close to, but clearly distinct from M. polaris, which potentially represents a new clade specific of the Antarctic. These results highlight the need for complementary strategies as well as the importance of year-round monitoring for a comprehensive description of phytoplankton communities in Antarctic coastal waters.
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Melucci D, Zappi A, Poggioli F, Morozzi P, Giglio F, Tositti L. ATR-FTIR Spectroscopy, a New Non-Destructive Approach for the Quantitative Determination of Biogenic Silica in Marine Sediments. Molecules 2019; 24:molecules24213927. [PMID: 31683504 PMCID: PMC6866127 DOI: 10.3390/molecules24213927] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 10/25/2019] [Accepted: 10/29/2019] [Indexed: 11/16/2022] Open
Abstract
Biogenic silica is the major component of the external skeleton of marine micro-organisms, such as diatoms, which, after the organisms death, settle down onto the seabed. These micro-organisms are involved in the CO2 cycle because they remove it from the atmosphere through photosynthesis. The biogenic silica content in marine sediments, therefore, is an indicator of primary productivity in present and past epochs, which is useful to study the CO2 trends. Quantification of biosilica in sediments is traditionally carried out by wet chemistry followed by spectrophotometry, a time-consuming analytical method that, besides being destructive, is affected by a strong risk of analytical biases owing to the dissolution of other silicatic components in the mineral matrix. In the present work, the biosilica content was directly evaluated in sediment samples, without chemically altering them, by attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. Quantification was performed by combining the multivariate standard addition method (MSAM) with the net analyte signal (NAS) procedure to solve the strong matrix effect of sediment samples. Twenty-one sediment samples from a sediment core and one reference standard sample were analyzed, and the results (extrapolated concentrations) were found to be comparable to those obtained by the traditional wet method, thus demonstrating the feasibility of the ATR-FTIR-MSAM-NAS approach as an alternative method for the quantification of biosilica. Future developments will cover in depth investigation on biosilica from other biogenic sources, the extension of the method to sediments of other provenance, and the use higher resolution IR spectrometers.
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Affiliation(s)
- Dora Melucci
- Department of Chemistry "G. Ciamician", University of Bologna, 40126 Bologna, Italy.
| | - Alessandro Zappi
- Department of Chemistry "G. Ciamician", University of Bologna, 40126 Bologna, Italy.
| | - Francesca Poggioli
- Department of Chemistry "G. Ciamician", University of Bologna, 40126 Bologna, Italy.
| | - Pietro Morozzi
- Department of Chemistry "G. Ciamician", University of Bologna, 40126 Bologna, Italy.
| | - Federico Giglio
- Polar Science Institute-National Research Council ISP-CNR, Via P. Gobetti 101, 40129 Bologna, Italy.
| | - Laura Tositti
- Department of Chemistry "G. Ciamician", University of Bologna, 40126 Bologna, Italy.
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Mangoni O, Saggiomo M, Bolinesi F, Castellano M, Povero P, Saggiomo V, DiTullio GR. Phaeocystis antarctica unusual summer bloom in stratified antarctic coastal waters (Terra Nova Bay, Ross Sea). Mar Environ Res 2019; 151:104733. [PMID: 31351585 DOI: 10.1016/j.marenvres.2019.05.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/17/2019] [Accepted: 05/18/2019] [Indexed: 06/10/2023]
Abstract
This study focuses on the potential explanations for a Phaeocystis antarctica summer bloom occurred in stratified waters of Terra Nova Bay (TNB) - which is part of the Antarctic Special Protected Area (n.161) in the Ross Sea - trough a multi-parameter correlative approach. Many previous studies have highlighted that water column stratification typically favors diatom dominance compared to the colonial haptophyte P. antarctica, in the Ross Sea, and this correlation has often been used to explain the historic dominance of diatoms in TNB. To explore the spatial and temporal progression of P. antarctica bloom in coastal waters, four stations were sampled three times each between December 31, 2009 and January 13, 2010. Taxonomic and pigment composition of phytoplankton communities, macro-nutrient concentrations and various different indices, all indicated the relative dominance of P. antarctica. Cell abundances revealed that P. antarctica contributed 79% of total cell counts in the upper 25 m and 93% in the lower photic zone. Similarly, a strong correlation was observed between Chl-a and the Hex:Fuco pigment ratio, corroborating the microscopic analyses. Recent studies have shown that iron can trigger colonial P. antarctica blooms. Based on the Hex:Chl-c3 proxy for iron limitation in P. antarctica, we hypothesize that anomalously higher iron fluxes were responsible for the unusual bloom of colonial P. antarctica observed in TNB.
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Affiliation(s)
- Olga Mangoni
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso di Monte Sant'Angelo, via Cinthia 21, Naples 80126, Italy; CoNISMa, Piazzale Flaminio 9, Rome 00196, Italy
| | - Maria Saggiomo
- Stazione Zoologica Anton Dohrn, Villa Comunale I, Naples 80122, Italy.
| | - Francesco Bolinesi
- Dipartimento di Biologia, Università degli Studi di Napoli Federico II, Complesso di Monte Sant'Angelo, via Cinthia 21, Naples 80126, Italy
| | - Michela Castellano
- Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Università degli Studi di Genova, Corso Europa 26, Genoa 16132, Italy
| | - Paolo Povero
- Dipartimento di Scienze della Terra, dell'Ambiente e della Vita, Università degli Studi di Genova, Corso Europa 26, Genoa 16132, Italy
| | - Vincenzo Saggiomo
- Stazione Zoologica Anton Dohrn, Villa Comunale I, Naples 80122, Italy
| | - Giacomo R DiTullio
- Hollings Marine Laboratory, College of Charleston, 331 Fort Johnson Rd, Charleston, SC 29412, USA
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Wu M, McCain JSP, Rowland E, Middag R, Sandgren M, Allen AE, Bertrand EM. Manganese and iron deficiency in Southern Ocean Phaeocystis antarctica populations revealed through taxon-specific protein indicators. Nat Commun 2019; 10:3582. [PMID: 31395884 PMCID: PMC6687791 DOI: 10.1038/s41467-019-11426-z] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 07/15/2019] [Indexed: 11/10/2022] Open
Abstract
Iron and light are recognized as limiting factors controlling Southern Ocean phytoplankton growth. Recent field-based evidence suggests, however, that manganese availability may also play a role. Here we examine the influence of iron and manganese on protein expression and physiology in Phaeocystis antarctica, a key Antarctic primary producer. We provide taxon-specific proteomic evidence to show that in-situ Southern Ocean Phaeocystis populations regularly experience stress due to combined low manganese and iron availability. In culture, combined low iron and manganese induce large-scale changes in the Phaeocystis proteome and result in reorganization of the photosynthetic apparatus. Natural Phaeocystis populations produce protein signatures indicating late-season manganese and iron stress, consistent with concurrently observed stimulation of chlorophyll production upon additions of manganese or iron. These results implicate manganese as an important driver of Southern Ocean productivity and demonstrate the utility of peptide mass spectrometry for identifying drivers of incomplete macronutrient consumption. Low manganese availability could be a major control of phytoplankton growth in the Southern Ocean. Here the authors identify proteomic signatures of low manganese and iron availability in phytoplankton cultures and detect those signatures in Antarctic field samples.
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Affiliation(s)
- Miao Wu
- Department of Biology, Dalhousie University, 1355 Oxford Street PO Box 15000, Halifax, B3H 4R2, NS, Canada.,Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7015, 750 07, Uppsala, Sweden
| | - J Scott P McCain
- Department of Biology, Dalhousie University, 1355 Oxford Street PO Box 15000, Halifax, B3H 4R2, NS, Canada
| | - Elden Rowland
- Department of Biology, Dalhousie University, 1355 Oxford Street PO Box 15000, Halifax, B3H 4R2, NS, Canada
| | - Rob Middag
- Department of Ocean Systems, NIOZ Royal Netherlands Institute for Sea Research, and Utrecht University, P.O. Box 59, Den Burg, Texel, 1790 AB, Netherlands
| | - Mats Sandgren
- Department of Molecular Sciences, Swedish University of Agricultural Sciences, Box 7015, 750 07, Uppsala, Sweden
| | - Andrew E Allen
- Microbial and Environmental Genomics, J. Craig Venter Institute, 4120 Capricorn Lane, La Jolla, CA, 92037, USA.,Integrative Oceanography Division, Scripps Institution of Oceanography, University of California, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Erin M Bertrand
- Department of Biology, Dalhousie University, 1355 Oxford Street PO Box 15000, Halifax, B3H 4R2, NS, Canada.
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Paterson JT, Rotella JJ, Arrigo KR, Garrott RA. Tight coupling of primary production and marine mammal reproduction in the Southern Ocean. Proc Biol Sci 2016; 282:20143137. [PMID: 25854885 DOI: 10.1098/rspb.2014.3137] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Polynyas are areas of open water surrounded by sea ice and are important sources of primary production in high-latitude marine ecosystems. The magnitude of annual primary production in polynyas is controlled by the amount of exposure to solar radiation and sensitivity to changes in sea-ice extent. The degree of coupling between primary production and production by upper trophic-level consumers in these environments is not well understood, which prevents reliable predictions about population trajectories for species at higher trophic levels under potential future climate scenarios. In this study, we find a strong, positive relationship between annual primary production in an Antarctic polynya and pup production by ice-dependent Weddell seals. The timing of the relationship suggests reproductive effort increases to take advantage of high primary production occurring in the months after the birth pulse. Though the proximate causal mechanism is unknown, our results indicate tight coupling between organisms at disparate trophic levels on a short timescale, deepen our understanding of marine ecosystem processes, and raise interesting questions about why such coupling exists and what implications it has for understanding high-latitude ecosystems.
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Affiliation(s)
| | - Jay J Rotella
- Department of Ecology, Montana State University, Bozeman, MT 59717, USA
| | - Kevin R Arrigo
- Department of Environmental Earth System Science, Stanford University, Stanford, CA 94305-4216, USA
| | - Robert A Garrott
- Department of Ecology, Montana State University, Bozeman, MT 59717, USA
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McKie-Krisberg ZM, Gast RJ, Sanders RW. Physiological responses of three species of Antarctic mixotrophic phytoflagellates to changes in light and dissolved nutrients. Microb Ecol 2015; 70:21-29. [PMID: 25482369 DOI: 10.1007/s00248-014-0543-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2014] [Accepted: 11/25/2014] [Indexed: 06/04/2023]
Abstract
Antarctic phototrophs are challenged by extreme temperatures, ice cover, nutrient limitation, and prolonged periods of darkness. Yet this environment may also provide niche opportunities for phytoplankton utilizing alternative nutritional modes. Mixotrophy, the combination of photosynthesis and particle ingestion, has been proposed as a mechanism for some phytoplankton to contend with the adverse conditions of the Antarctic. We conducted feeding experiments using fluorescent bacteria-sized tracers to compare the effects of light and nutrients on bacterivory rates in three Antarctic marine photosynthetic nanoflagellates representing two evolutionary lineages: Cryptophyceae (Geminigera cryophila) and Prasinophyceae (Pyramimonas tychotreta and Mantoniella antarctica). Only G. cryophila had previously been identified as mixotrophic. We also measured photoautotrophic abilities over a range of light intensities (P vs. I) and used dark survival experiments to assess cell population dynamics in the absence of light. Feeding behavior in these three nanoflagellates was affected by either light, nutrient levels, or a combination of both factors in a species-specific manner that was not conserved by evolutionary lineage. The different responses to environmental factors by these mixotrophs supported the idea of tradeoffs in the use of phagotrophy and phototrophy for growth.
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Affiliation(s)
- Zaid M McKie-Krisberg
- Department of Biology, Temple University, 1900 N. 12th St., Philadelphia, PA, 19122, USA,
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11
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Goldman JAL, Kranz SA, Young JN, Tortell PD, Stanley RHR, Bender ML, Morel FMM. Gross and net production during the spring bloom along the Western Antarctic Peninsula. New Phytol 2015; 205:182-191. [PMID: 25382393 DOI: 10.1111/nph.13125] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 09/15/2014] [Indexed: 06/04/2023]
Abstract
This study explores some of the physiological mechanisms responsible for high productivity near the shelf in the Western Antarctic Peninsula despite a short growing season and cold temperature. We measured gross and net primary production at Palmer Station during the summer of 2012/2013 via three different techniques: incubation with H2 (18) O; incubation with (14) CO2 ; and in situ measurements of O2 /Ar and triple oxygen isotope. Additional laboratory experiments were performed with the psychrophilic diatom Fragilariopsis cylindrus. During the spring bloom, which accounted for more than half of the seasonal gross production at Palmer Station, the ratio of net-to-gross production reached a maximum greater than c. 60%, among the highest ever reported. The use of multiple techniques showed that these high ratios resulted from low heterotrophic respiration and very low daylight autotrophic respiration. Laboratory experiments revealed a similar ratio of net-to-gross O2 production in F. cylindrus and provided the first experimental evidence for an important level of cyclic electron flow (CEF) in this organism. The low ratio of community respiration to gross primary production observed during the bloom at Palmer Station may be characteristic of high latitude coastal ecosystems and partially supported by a very active CEF in psychrophilic phytoplankton.
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12
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Nunn BL, Faux JF, Hippmann AA, Maldonado MT, Harvey HR, Goodlett DR, Boyd PW, Strzepek RF. Diatom proteomics reveals unique acclimation strategies to mitigate Fe limitation. PLoS One 2013; 8:e75653. [PMID: 24146769 PMCID: PMC3797725 DOI: 10.1371/journal.pone.0075653] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Accepted: 08/17/2013] [Indexed: 11/19/2022] Open
Abstract
Phytoplankton growth rates are limited by the supply of iron (Fe) in approximately one third of the open ocean, with major implications for carbon dioxide sequestration and carbon (C) biogeochemistry. To date, understanding how alteration of Fe supply changes phytoplankton physiology has focused on traditional metrics such as growth rate, elemental composition, and biophysical measurements such as photosynthetic competence (Fv/Fm). Researchers have subsequently employed transcriptomics to probe relationships between changes in Fe supply and phytoplankton physiology. Recently, studies have investigated longer-term (i.e. following acclimation) responses of phytoplankton to various Fe conditions. In the present study, the coastal diatom, Thalassiosira pseudonana, was acclimated (10 generations) to either low or high Fe conditions, i.e. Fe-limiting and Fe-replete. Quantitative proteomics and a newly developed proteomic profiling technique that identifies low abundance proteins were employed to examine the full complement of expressed proteins and consequently the metabolic pathways utilized by the diatom under the two Fe conditions. A total of 1850 proteins were confidently identified, nearly tripling previous identifications made from differential expression in diatoms. Given sufficient time to acclimate to Fe limitation, T. pseudonana up-regulates proteins involved in pathways associated with intracellular protein recycling, thereby decreasing dependence on extracellular nitrogen (N), C and Fe. The relative increase in the abundance of photorespiration and pentose phosphate pathway proteins reveal novel metabolic shifts, which create substrates that could support other well-established physiological responses, such as heavily silicified frustules observed for Fe-limited diatoms. Here, we discovered that proteins and hence pathways observed to be down-regulated in short-term Fe starvation studies are constitutively expressed when T. pseudonana is acclimated (i.e., nitrate and nitrite transporters, Photosystem II and Photosystem I complexes). Acclimation of the diatom to the desired Fe conditions and the comprehensive proteomic approach provides a more robust interpretation of this dynamic proteome than previous studies.
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Affiliation(s)
- Brook L. Nunn
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
- Medicinal Chemistry Department, University of Washington, Seattle, Washington, United States of America
| | - Jessica F. Faux
- University of Maryland Center for Environmental Science, Chesapeake Biological Laboratory, Solomons, Maryland, United States of America
| | - Anna A. Hippmann
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - Maria T. Maldonado
- Department of Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | - H. Rodger Harvey
- Department of Ocean, Earth and Atmospheric Science, Old Dominion University, Norfolk, Virginia, United States of America
| | - David R. Goodlett
- Department of Genome Sciences, University of Washington, Seattle, Washington, United States of America
| | - Philip W. Boyd
- NIWA Centre for Chemical and Physical Oceanography, Department of Chemistry, University of Otago, Dunedin, New Zealand
| | - Robert F. Strzepek
- Research School of Earth Sciences, The Australian National University, Canberra, Australia
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Abstract
The continental shelf of the Ross Sea exhibits substantial variations in physical forcing, ice cover, and biological processes on a variety of time and space scales. Its circulation is characterized by advective inputs from the east and exchanges with off-shelf regions via the troughs along the northern portions. Phytoplankton biomass is greater there than anywhere else in the Antarctic, although nitrate is rarely reduced to levels below 10 μmol L(-1). Overall growth is regulated by irradiance (via ice at the surface and by the depths of the mixed layers) and iron concentrations. Apex predators reach exceptional abundances, and the world's largest colonies of Adélie and emperor penguins are found there. Krill are represented by two species (Euphausia superba near the shelf break and Euphausia crystallorophias throughout the continental shelf region). Equally important and poorly known is the Antarctic silverfish (Pleuragramma antarcticum), which is also consumed by most upper-trophic-level predators. Future changes in the Ross Sea environment will have profound and unpredictable effects on the food web.
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Affiliation(s)
- Walker O Smith
- Virginia Institute of Marine Science, College of William & Mary, Gloucester Point, Virginia 23062;
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Boyd PW, Arrigo KR, Strzepek R, van Dijken GL. Mapping phytoplankton iron utilization: Insights into Southern Ocean supply mechanisms. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jc007726] [Citation(s) in RCA: 88] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Alderkamp AC, Kulk G, Buma AGJ, Visser RJW, Van Dijken GL, Mills MM, Arrigo KR. THE EFFECT OF IRON LIMITATION ON THE PHOTOPHYSIOLOGY OF PHAEOCYSTIS ANTARCTICA (PRYMNESIOPHYCEAE) AND FRAGILARIOPSIS CYLINDRUS (BACILLARIOPHYCEAE) UNDER DYNAMIC IRRADIANCE(1). J Phycol 2012; 48:45-59. [PMID: 27009649 DOI: 10.1111/j.1529-8817.2011.01098.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
The effects of iron limitation on photoacclimation to dynamic irradiance were studied in Phaeocystis antarctica G. Karst. and Fragilariopsis cylindrus (Grunow) W. Krieg. in terms of growth rate, photosynthetic parameters, pigment composition, and fluorescence characteristics. Under dynamic light conditions mimicking vertical mixing below the euphotic zone, P. antarctica displayed higher growth rates than F. cylindrus both under iron (Fe)-replete and Fe-limiting conditions. Both species showed xanthophyll de-epoxidation that was accompanied by low levels of nonphotochemical quenching (NPQ) during the irradiance maximum of the light cycle. The potential for NPQ at light levels corresponding to full sunlight was substantial in both species and increased under Fe limitation in F. cylindrus. Although the decline in Fv /Fm under Fe limitation was similar in both species, the accompanying decrease in the maximum rate of photosynthesis and growth rate was much stronger in F. cylindrus. Analysis of the electron transport rates through PSII and on to carbon (C) fixation revealed a large potential for photoprotective cyclic electron transport (CET) in F. cylindrus, particularly under Fe limitation. Probably, CET aided the photoprotection in F. cylindrus, but it also reduced photosynthetic efficiency at higher light intensities. P. antarctica, on the other hand, was able to efficiently use electrons flowing through PSII for C fixation at all light levels, particularly under Fe limitation. Thus, Fe limitation enhanced the photophysiological differences between P. antarctica and diatoms, supporting field observations where P. antarctica is found to dominate deeply mixed water columns, whereas diatoms dominate shallower mixed layers.
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Affiliation(s)
- Anne-Carlijn Alderkamp
- Department of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands Department of Environmental Earth System Science, Stanford University, Stanford, California 94305, USADepartment of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The NetherlandsDepartment of Environmental Earth System Science, Stanford University, Stanford, California 94305, USA
| | - Gemma Kulk
- Department of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands Department of Environmental Earth System Science, Stanford University, Stanford, California 94305, USADepartment of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The NetherlandsDepartment of Environmental Earth System Science, Stanford University, Stanford, California 94305, USA
| | - Anita G J Buma
- Department of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands Department of Environmental Earth System Science, Stanford University, Stanford, California 94305, USADepartment of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The NetherlandsDepartment of Environmental Earth System Science, Stanford University, Stanford, California 94305, USA
| | - Ronald J W Visser
- Department of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands Department of Environmental Earth System Science, Stanford University, Stanford, California 94305, USADepartment of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The NetherlandsDepartment of Environmental Earth System Science, Stanford University, Stanford, California 94305, USA
| | - Gert L Van Dijken
- Department of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands Department of Environmental Earth System Science, Stanford University, Stanford, California 94305, USADepartment of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The NetherlandsDepartment of Environmental Earth System Science, Stanford University, Stanford, California 94305, USA
| | - Matthew M Mills
- Department of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands Department of Environmental Earth System Science, Stanford University, Stanford, California 94305, USADepartment of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The NetherlandsDepartment of Environmental Earth System Science, Stanford University, Stanford, California 94305, USA
| | - Kevin R Arrigo
- Department of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The Netherlands Department of Environmental Earth System Science, Stanford University, Stanford, California 94305, USADepartment of Ocean Ecosystems, Energy and Sustainability Research Institute, University of Groningen, Nijenborgh 7, 9747 AG, Groningen, The NetherlandsDepartment of Environmental Earth System Science, Stanford University, Stanford, California 94305, USA
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Long MC, Dunbar RB, Tortell PD, Smith WO, Mucciarone DA, DiTullio GR. Vertical structure, seasonal drawdown, and net community production in the Ross Sea, Antarctica. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2009jc005954] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Arrigo KR, Mills MM, Kropuenske LR, van Dijken GL, Alderkamp AC, Robinson DH. Photophysiology in Two Major Southern Ocean Phytoplankton Taxa: Photosynthesis and Growth of Phaeocystis antarctica and Fragilariopsis cylindrus under Different Irradiance Levels. Integr Comp Biol 2010; 50:950-66. [DOI: 10.1093/icb/icq021] [Citation(s) in RCA: 111] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Mangoni O, Saggiomo M, Modigh M, Catalano G, Zingone A, Saggiomo V. The role of platelet ice microalgae in seeding phytoplankton blooms in Terra Nova Bay (Ross Sea, Antarctica): a mesocosm experiment. Polar Biol 2008. [DOI: 10.1007/s00300-008-0507-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Reddy TE, Arrigo KR, Holland DM. The role of thermal and mechanical processes in the formation of the Ross Sea summer polynya. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jc003874] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Miller L, DiTullio G. Chapter 5 Gas Fluxes and Dynamics in Polynyas. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/s0422-9894(06)74005-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
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Abstract
An apparent trophic cascade that appears during summer in the western Ross Sea, Antarctica, explains why the Antarctic silverfish (Pleuragramma antarcticum) there becomes cannibalistic; its principal prey, crystal krill (Euphausia crystallorophias) becomes scarce; and the diatom community is minimally grazed compared to adjacent areas. The krill is the major grazer of diatoms. On the basis of fieldwork at Ross Island, we suggest that the cascade results from foraging by unusually numerous Adélie Penguins (Pygoscelis adeliae), minke whales (Balaenoptera bonaerensis), and fish-eating killer whales (Orcinus orca). These species and other top predators apparently deplete the krill and silverfish. In drawing our conclusions, we were aided by two "natural experiments." In one "experiment," large, grounded icebergs altered the seasonal pattern of change in regional sea-ice cover, but not the seasonal change in penguin diet and foraging behavior that was also detected during the pre-iceberg era. In the other "experiment," a short-term polynya (opening in the ice) brought penguins and whales together in a confined area, this time altering both penguin diet and foraging behavior. We conclude that the foraging of penguins and whales, and not a formerly hypothesized seasonal decrease in sea-ice cover, explains (1) the annual switch in the penguins' prey from krill to silverfish, (2) the subsequent lengthening of penguin foraging trips, and (3) a marked decline of cetaceans in the area later in the season. Reduction in the middle-trophic-level prey is expressed in the relaxed grazing pressure on phytoplankton.
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Affiliation(s)
- David G Ainley
- H. T. Harvey and Associates, 3150 Almaden Expressway, Suite 145, San Jose, California 95118, USA.
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Pabi S, Arrigo KR. Satellite estimation of marine particulate organic carbon in waters dominated by different phytoplankton taxa. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2005jc003137] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Largiuni O, Becagli S, Innocenti M, Stortini AM, Traversi R, Udisti R. Formaldehyde determination in seawater. Preliminary application to coastal samples at Terra Nova Bay (Antarctica). J Environ Monit 2005; 7:1299-304. [PMID: 16307087 DOI: 10.1039/b507334k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A sensitive spectrofluorimetric-FIA (flow injection analysis) method for formaldehyde (HCHO) determination was improved with the aim of analysing seawater samples. The fluorescence emission versus HCHO concentration shows a linear pattern from sub microg L(-1) to about 1000 microg L(-1). The reproducibility at 15 ppb level is about 2%. Interferences from other aldehydes were checked; only glyoxal shows a significative interference, but only when its concentration is about 6000 times higher than that of formaldehyde. Superficial (microlayer, just sub-pack or sea-ice free sea surface) and deep (along the water column, sub-pack or in sea-ice free areas) seawater samples were collected near the coast at Terra Nova Bay (Ross Sea, Antarctica) during the 1998/1999 and 2001/2002 Italian Antarctic Expedition. We report here the preliminary results of the spectrofluorimetric-FIA determination of the HCHO content. The mean seawater superficial formaldehyde concentration was 15 microg L(-1); the concentration along the water column ranged between 4.5 to over 40 microg L(-1)(20 microg L(-1) mean concentration), usually with a maximum value for the 30 m depth, corresponding to a fluorescence maximum. The sampling was repeated 7 times in the austral summer in order to evaluate seasonal changes in the formaldehyde concentration/seawater depth profiles. The results show changes in the formaldehyde concentration at different depths.
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Affiliation(s)
- O Largiuni
- Centre for Geotechnologies, University of Siena, V. Vetri Vecchi 34, I-52027, San Giovanni Valdarno (AR), Arezzo, Italy.
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Affiliation(s)
- Kevin R. Arrigo
- Department of Geophysics; Stanford University; Stanford California USA
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Tagliabue A, Arrigo KR. Iron in the Ross Sea: 1. Impact on CO2
fluxes via variation in phytoplankton functional group and non-Redfield stoichiometry. ACTA ACUST UNITED AC 2005. [DOI: 10.1029/2004jc002531] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
| | - Kevin R. Arrigo
- Department of Geophysics; Stanford University; Stanford California USA
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Corami F, Capodaglio G, Turetta C, Soggia F, Magi E, Grotti M. Summer distribution of trace metals in the western sector of the Ross Sea, Antarctica. ACTA ACUST UNITED AC 2005; 7:1256-64. [PMID: 16307081 DOI: 10.1039/b507323p] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The more important water masses generated by the interaction of Circumpolar Deep Water and the shelf waters in the western sector of the Ross Sea are characterized for trace element contents. The distribution of cadmium, lead, copper, zinc, iron, manganese and chromium during the austral summer is analysed and discussed according to the physical, chemical and biological processes which affect the composition of the water masses. The Cd concentration is found to have a relative high variability that can be related to biological activity and the water mass age, MCDW presents a mean dissolved concentration (SD) of 0.77 (0.07) nmol kg(-1), while the HSSW and AASW have a mean concentration of 0.63 (0.06) and 0.61 (0.16) nmol kg(-1), respectively. Lead features the typical distribution of a scavenged element with a surface maximum ranging between 22 and 130 pmol kg(-1) decreasing to 11 pmol kg(-1) in deep waters. However, the vertical distribution in the shelf area features a maximum concentration in intermediate/deep waters and we can hypothesize that the distribution may be influenced by more than one source. The surface dissolved concentration of zinc and copper were un-homogeneously distributed, the mean (SD) values were 5.25 (2.92) and 1.99 (1.49) nmol kg(-1) for zinc and copper, respectively and increased with depth for both the elements. We may therefore hypothesize enrichment in the dissolved phase deriving from recycling in deep waters. 95% of the chromium was in dissolved form and showed a superficial depletion; the mean concentrations were 1.6 +/- 0.2 and 2.6 +/- 0.8 nmol kg(-1) for surface and deep waters respectively. The vertical distribution of dissolved manganese was quite homogeneous with a mean concentration 0.96 +/- 0.7 nmol kg(-1). The particulate iron and manganese concentration trends are similar and feature a significant bottom increase implying a significant input from resuspension; the mean concentration of particulate ranged between 1.4 and 7.4 nmol kg(-1) for iron and ranged between 0.072 and 0.29 nmol kg(-1) for manganese.
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Affiliation(s)
- F Corami
- Department of Environmental Sciences, University of Venice Ca' Foscari, Dorsoduro 2137, 30123, Venice, Italy
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Sweeney C. The annual cycle of surface water CO2 And O2 in the Ross Sea: A model for gas exchange on the continental shelves of Antarctica. Biogeochemistry of the Ross Sea 2003. [DOI: 10.1029/078ars19] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Maucher JM, Ditullio GR. Flavodoxin as a diagnostic indicator of chronic iron limitation in the Ross Sea and New Zealand sector of the Southern Ocean. In: Ditullio GR, Dunbar RB, editors. Biogeochemistry of the Ross Sea. Washington: American Geophysical Union; 2003. pp. 209-19. [DOI: 10.1029/078ars13] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Robinson DH, Arrigo KR, Ditullio GR, Lizotte MP. Evaluating photosynthetic carbon fixation during Phaeocystis Antarctica blooms. In: Ditullio GR, Dunbar RB, editors. Biogeochemistry of the Ross Sea. Washington: American Geophysical Union; 2003. pp. 77-91. [DOI: 10.1029/078ars05] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Dunbar RB, Arrigo KR, Lutz M, DiTullio GR, Leventer AR, Lizotte MP, Van Woert ML, Robinson DH. Non-Redfield production and export of marine organic matter: A recurrent part of the annual cycle in the Ross Sea, Antarctica. Biogeochemistry of the Ross Sea 2003. [DOI: 10.1029/078ars11] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Garrison DL, Gibson A, Kunze H, Gowing MM, Vickers CL, Mathot S, Bayre RC. The Ross Sea Polynya Project: Diatom- and Phaeocystis-dominated phytoplankton assemblages in the Ross Sea, Antarctica, 1994–1996. In: Ditullio GR, Dunbar RB, editors. Biogeochemistry of the Ross Sea. Washington: American Geophysical Union; 2003. pp. 53-76. [DOI: 10.1029/078ars04] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Worthen DL, Arrigo KR. A coupled ocean-ecosystem model of the Ross Sea. Part 1: Interannual variability of primary production and phytoplankton community structure. In: Ditullio GR, Dunbar RB, editors. Biogeochemistry of the Ross Sea. Washington: American Geophysical Union; 2003. pp. 93-105. [DOI: 10.1029/078ars06] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Barry JP, Grebmeier JM, Smith J, Dunbar RB. Oceanographic versus seafloor-habitat control of benthic megafaunal communities in the S.W. Ross Sea, Antarctica. Biogeochemistry of the Ross Sea 2003. [DOI: 10.1029/078ars21] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Grebmeier JM, Ditullio GR, Barry JP, Cooper LW. Benthic carbon cycling in the Ross Sea Polynya, Antarctica: Benthic community metabolism and sediment tracers. In: Ditullio GR, Dunbar RB, editors. Biogeochemistry of the Ross Sea. Washington: American Geophysical Union; 2003. pp. 313-26. [DOI: 10.1029/078ars20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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Arrigo KR. A coupled ocean-ecosystem model of the Ross Sea: 2. Iron regulation of phytoplankton taxonomic variability and primary production. ACTA ACUST UNITED AC 2003. [DOI: 10.1029/2001jc000856] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Lourey MJ, Trull TW. Seasonal nutrient depletion and carbon export in the Subantarctic and Polar Frontal zones of the Southern Ocean south of Australia. ACTA ACUST UNITED AC 2001. [DOI: 10.1029/2000jc000287] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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DiTullio GR, Grebmeier JM, Arrigo KR, Lizotte MP, Robinson DH, Leventer A, Barry JP, VanWoert ML, Dunbar RB. Rapid and early export of Phaeocystis antarctica blooms in the Ross Sea, Antarctica. Nature 2000; 404:595-8. [PMID: 10766240 DOI: 10.1038/35007061] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The Southern Ocean is very important for the potential sequestration of carbon dioxide in the oceans and is expected to be vulnerable to changes in carbon export forced by anthropogenic climate warming. Annual phytoplankton blooms in seasonal ice zones are highly productive and are thought to contribute significantly to pCO2 drawdown in the Southern Ocean. Diatoms are assumed to be the most important phytoplankton class with respect to export production in the Southern Ocean; however, the colonial prymnesiophyte Phaeocystis antarctica regularly forms huge blooms in seasonal ice zones and coastal Antarctic waters. There is little evidence regarding the fate of carbon produced by P. antarctica in the Southern Ocean, although remineralization in the upper water column has been proposed to be the main pathway in polar waters. Here we present evidence for early and rapid carbon export from P. antarctica blooms to deep water and sediments in the Ross Sea. Carbon sequestration from P. antarctica blooms may influence the carbon cycle in the Southern Ocean, especially if projected climatic changes lead to an alteration in the structure of the phytoplankton community.
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Affiliation(s)
- G R DiTullio
- University of Charleston, Grice Marine Laboratory, South Carolina 29412, USA.
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