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Liang Z, McCabe K, Fawcett SE, Forrer HJ, Hashihama F, Jeandel C, Marconi D, Planquette H, Saito MA, Sohm JA, Thomas RK, Letscher RT, Knapp AN. A global ocean dissolved organic phosphorus concentration database (DOPv2021). Sci Data 2022; 9:772. [PMID: 36526638 PMCID: PMC9758185 DOI: 10.1038/s41597-022-01873-7] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 11/24/2022] [Indexed: 12/23/2022] Open
Abstract
Dissolved organic phosphorus (DOP) concentration distributions in the global surface ocean inform our understanding of marine biogeochemical processes such as nitrogen fixation and primary production. The spatial distribution of DOP concentrations in the surface ocean reflect production by primary producers and consumption as an organic nutrient by phytoplankton including diazotrophs and other microbes, as well as other loss processes such as photolysis. Compared to dissolved organic carbon and nitrogen, however, relatively few marine DOP concentration measurements have been made, largely due to the lack of automated analysis techniques. Here we present a database of marine DOP concentration measurements (DOPv2021) that includes new (n = 730) and previously published (n = 3140) observations made over the last ~30 years (1990-2021), including 1751 observations in the upper 50 m. This dataset encompasses observations from all major ocean basins including the poorly represented Indian, South Pacific, and Southern Oceans and provides insight into spatial distributions of DOP in the ocean. It is also valuable for researchers who work on marine primary production and nitrogen fixation.
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Affiliation(s)
- Zhou Liang
- grid.255986.50000 0004 0472 0419Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL USA
| | - Kelly McCabe
- grid.214458.e0000000086837370Copperative Institute for Great Lakes Research (CIGLR), School for Environment and Sustainability, University of Michigan, Ann Arbor, MI USA
| | - Sarah E. Fawcett
- grid.7836.a0000 0004 1937 1151Department of Oceanography, Faculty of Science, University of Cape Town, Cape Town, South Africa ,grid.7836.a0000 0004 1937 1151Marine and Antarctic Research centre for Innovation and Sustainability (MARIS), University of Cape Town, Cape Town, South Africa
| | - Heather J. Forrer
- grid.255986.50000 0004 0472 0419Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL USA
| | - Fuminori Hashihama
- grid.412785.d0000 0001 0695 6482Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Catherine Jeandel
- grid.503277.40000 0004 0384 4620LEGOS, Université de Toulouse, CNRS, IRD, CNES, UPS, Toulouse, France
| | - Dario Marconi
- grid.16750.350000 0001 2097 5006Department of Geosciences, Princeton University, Princeton, NJ USA
| | - Hélène Planquette
- grid.463763.30000 0004 0638 0577Univ Brest, CNRS, IRD, Ifremer, LEMAR, F-29280 Plouzane, France
| | - Mak A. Saito
- grid.56466.370000 0004 0504 7510Woods Hole Oceanographic Institution, Falmouth, MA USA
| | - Jill A. Sohm
- grid.42505.360000 0001 2156 6853Department of Biological Sciences, University of Southern California, Los Angeles, CA USA
| | - Rachel K. Thomas
- grid.255986.50000 0004 0472 0419Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL USA
| | - Robert T. Letscher
- grid.167436.10000 0001 2192 7145Earth Sciences & Ocean Process Analysis Laboratory, University of New Hampshire, Durham, NH USA
| | - Angela N. Knapp
- grid.255986.50000 0004 0472 0419Department of Earth, Ocean, and Atmospheric Science, Florida State University, Tallahassee, FL USA
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Yamaguchi T, Sato M, Hashihama F, Kato H, Sugiyama T, Ogawa H, Takahashi K, Furuya K. Longitudinal and Vertical Variations of Dissolved Labile Phosphoric Monoesters and Diesters in the Subtropical North Pacific. Front Microbiol 2021; 11:570081. [PMID: 33552003 PMCID: PMC7854537 DOI: 10.3389/fmicb.2020.570081] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2020] [Accepted: 10/30/2020] [Indexed: 11/30/2022] Open
Abstract
The labile fraction of dissolved organic phosphorus (DOP) – predominantly consisting of phosphoric esters – is an important microbial P source in the subtropical oligotrophic ocean. However, unlike phosphate, knowledge for labile DOP is still limited due to the scarcity of broad and intensive observations. In this study, we examined the concentrations and size-fractionated hydrolysis rates of labile phosphoric monoesters and diesters along a >10,000 km longitudinal transect in the North Pacific (23°N; upper 200-m layer). Depth-integrated monoesters decreased westward with a maximum difference of fivefold. Vertical profiles of monoesters in the eastern and western basins showed decreasing and increasing trends with depth, respectively. The monoester-depleted shallow layer of the western basin was associated with phosphate depletion and monoesterase activity was predominant in the large size fraction (>0.8 μm), suggesting that monoesters are significant P sources particularly for large microbes. In contrast, diester concentrations were generally lower than monoester concentrations and showed no obvious horizontal or vertical variation in the study area. Despite the unclear distribution pattern of diesters, diesterase activity in the particulate fraction (>0.2 μm) increased in the phosphate-depleted shallow layer of the western basin, suggesting that the targeted diesters in the assay were also important microbial P sources. Diesterase activities in the dissolved fraction (<0.2 μm) were not correlated with ambient phosphate concentrations; however, cell-free diesterase likely played a key role in P cycling, as dissolved diesterase activities were substantially higher than those in the particulate fraction. The horizontal and vertical variability of labile monoesters in the subtropical North Pacific were therefore predominantly regulated by P stress in particularly large microbes, whereas the distributions of labile diesters and diesterase activities were generally independent of microbial P stress, indicating a more complex regulation of diesters to that of monoesters.
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Affiliation(s)
- Tamaha Yamaguchi
- Fisheries Resources Institute, Japan Fisheries Research and Education Agency, Yokohama, Japan.,Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Mitsuhide Sato
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Graduate School of Fisheries and Environmental Sciences, Nagasaki University, Nagasaki, Japan
| | - Fuminori Hashihama
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Haruka Kato
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Takanori Sugiyama
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Hiroshi Ogawa
- Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan
| | - Kazutaka Takahashi
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Ken Furuya
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Graduate School of Science and Engineering, Soka University, Tokyo, Japan
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Yasui-Tamura S, Hashihama F, Ogawa H, Nishimura T, Kanda J. Automated simultaneous determination of total dissolved nitrogen and phosphorus in seawater by persulfate oxidation method. Talanta Open 2020. [DOI: 10.1016/j.talo.2020.100016] [Citation(s) in RCA: 8] [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: 11/25/2022] Open
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Takeda N, Hashihama F, Kanda J. Automated colorimetric determination of nanomolar urea in seawater by gas-segmented continuous flow analysis using a liquid waveguide capillary cell. Talanta 2020; 208:120371. [PMID: 31816767 DOI: 10.1016/j.talanta.2019.120371] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 09/17/2019] [Accepted: 09/18/2019] [Indexed: 11/18/2022]
Abstract
A sensitive automated colorimetric method for the determination of nanomolar concentration of urea in seawater is presented. The colorimetry was based on the diacetyl monoxime method and the automated system was constructed by a gas-segmented continuous flow analyzer equipped with a 100 cm path length of liquid waveguide capillary cell. The most suitable surfactant for the system was hexadecyl-trimethyl-ammonium-bromide as compared to Brij-35, sodium dodecyl sulfate, and Triton X-100. Blank selection using a 3% NaCl solution, filtered subtropical surface seawater, and filtered deep seawaters with and without urease treatment showed that the filtered deep seawater with urease treatment had the lowest absorbance and was appropriate. The sample volume needed for the analysis was 1.8 mL, and the analysis rate was 10 samples h-1. Calibration curves showed good linearity for 0-1000 nM urea-N concentration range (r2 = 0.999). The detection limit was 5 nM urea-N. The coefficient of variation for the analysis of seawater samples collected in the subtropical North Pacific was <5% at 30 and 29 nM urea-N. The proposed analytical system was applicable to vertical observation in the subtropical North Pacific.
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Affiliation(s)
- Noriko Takeda
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo, 108-8477, Japan.
| | - Fuminori Hashihama
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo, 108-8477, Japan.
| | - Jota Kanda
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo, 108-8477, Japan
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Martiny AC, Lomas MW, Fu W, Boyd PW, Chen YLL, Cutter GA, Ellwood MJ, Furuya K, Hashihama F, Kanda J, Karl DM, Kodama T, Li QP, Ma J, Moutin T, Woodward EMS, Moore JK. Biogeochemical controls of surface ocean phosphate. Sci Adv 2019; 5:eaax0341. [PMID: 31489372 PMCID: PMC6713502 DOI: 10.1126/sciadv.aax0341] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 07/18/2019] [Indexed: 05/26/2023]
Abstract
Surface ocean phosphate is commonly below the standard analytical detection limits, leading to an incomplete picture of the global variation and biogeochemical role of phosphate. A global compilation of phosphate measured using high-sensitivity methods revealed several previously unrecognized low-phosphate areas and clear regional differences. Both observational climatologies and Earth system models (ESMs) systematically overestimated surface phosphate. Furthermore, ESMs misrepresented the relationships between phosphate, phytoplankton biomass, and primary productivity. Atmospheric iron input and nitrogen fixation are known important controls on surface phosphate, but model simulations showed that differences in the iron-to-macronutrient ratio in the vertical nutrient supply and surface lateral transport are additional drivers of phosphate concentrations. Our study demonstrates the importance of accurately quantifying nutrients for understanding the regulation of ocean ecosystems and biogeochemistry now and under future climate conditions.
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Affiliation(s)
- Adam C. Martiny
- Department of Earth System Science, University of California, Irvine, Irvine, CA 92697, USA
- Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, CA 92697, USA
| | - Michael W. Lomas
- Bigelow Laboratory for Ocean Sciences, East Boothbay, ME 04544, USA
| | - Weiwei Fu
- Department of Earth System Science, University of California, Irvine, Irvine, CA 92697, USA
| | - Philip W. Boyd
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Tasmania, Australia
| | - Yuh-ling L. Chen
- Department of Oceanography, National Sun Yat-sen University, Kaohsiung, Taiwan
| | - Gregory A. Cutter
- Department of Ocean, Earth, and Atmospheric Sciences, Old Dominion University, Norfolk, VA 23529, USA
| | - Michael J. Ellwood
- Research School of Earth Sciences, Australian National University, Canberra, ACT 2601, Australia
| | - Ken Furuya
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo 113-8657, Japan
| | - Fuminori Hashihama
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo 108-8477, Japan
| | - Jota Kanda
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo 108-8477, Japan
| | - David M. Karl
- Daniel K. Inouye Center for Microbial Oceanography, University of Hawaii at Manoa, Honolulu, HI 96822, USA
| | - Taketoshi Kodama
- Japan Sea National Fisheries Research Institute, Japan Fisheries Research and Education Agency, 1-5939-22, Suido-cho, Chuo, Niigata, Japan
| | - Qian P. Li
- South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, People’s Republic of China
| | - Jian Ma
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen 361102, People’s Republic of China
| | - Thierry Moutin
- Aix Marseille Université, CNRS, Université de Toulon, IRD, OSU Pythéas, Mediterranean Institute of Oceanography (MIO), UM 110, 13288 Marseille, France
| | | | - J. Keith Moore
- Department of Earth System Science, University of California, Irvine, Irvine, CA 92697, USA
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Azimuddin KM, Hirai J, Suzuki S, Haider MN, Tachibana A, Watanabe K, Kitamura M, Hashihama F, Takahashi K, Hamasaki K. Possible association of diazotrophs with marine zooplankton in the Pacific Ocean. Microbiologyopen 2016; 5:1016-1026. [PMID: 27353240 PMCID: PMC5221459 DOI: 10.1002/mbo3.385] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Revised: 05/03/2016] [Accepted: 05/16/2016] [Indexed: 11/17/2022] Open
Abstract
Dinitrogen fixation, the biological reduction in N2 gas to ammonia contributes to the supply of new nitrogen in the surface ocean. To understand the diversity and abundance of potentially diazotrophic (N2 fixing) microorganisms associated with marine zooplankton, especially copepods, the nifH gene was studied using zooplankton samples collected in the Pacific Ocean. In total, 257 nifH sequences were recovered from 23 nifH‐positive DNA extracts out of 90 copepod samples. The nifH genes derived from cyanobacteria related to Trichodesmium, α‐ and γ‐subdivisions of proteobacteria, and anaerobic euryarchaeota related to Methanosaeta concilii were detected. Our results indicated that Pleuromamma, Pontella, and Euchaeta were the major copepod genera hosting dinitrogen fixers, though we found no species‐specific association between copepods and dinitrogen fixers. Also, the digital PCR provided novel data on the number of copies of the nifH gene in individual copepods, which we report the range from 30 to 1666 copies per copepod. This study is the first systematic study of zooplankton‐associated diazotrophs, covering a large area of the open ocean, which provide a clue to further study of a possible new hotspot of N2 fixation.
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Affiliation(s)
- Kazi Md Azimuddin
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Junya Hirai
- National Research Institute of Fisheries Science, Fisheries Research Agency, Yokohama, Kanagawa, Japan
| | - Shotaro Suzuki
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Md Nurul Haider
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Aiko Tachibana
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Keigo Watanabe
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan
| | - Minoru Kitamura
- Japan Agency for Marine-Earth Science and Technology, Yokosuka, Kanagawa, Japan
| | - Fuminori Hashihama
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Minato-Ku, Tokyo, Japan
| | - Kazutaka Takahashi
- Department of Aquatic Science, Graduate School of Agriculture and Life Sciences, The University of Tokyo, Bunkyo-Ku, Tokyo, Japan
| | - Koji Hamasaki
- Atmosphere and Ocean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan
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Ehama M, Hashihama F, Kinouchi S, Kanda J, Saito H. Sensitive determination of total particulate phosphorus and particulate inorganic phosphorus in seawater using liquid waveguide spectrophotometry. Talanta 2016; 153:66-70. [PMID: 27130091 DOI: 10.1016/j.talanta.2016.02.058] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Revised: 02/24/2016] [Accepted: 02/25/2016] [Indexed: 10/22/2022]
Abstract
Determining the total particulate phosphorus (TPP) and particulate inorganic phosphorus (PIP) in oligotrophic oceanic water generally requires the filtration of a large amount of water sample. This paper describes methods that require small filtration volumes for determining the TPP and PIP concentrations. The methods were devised by validating or improving conventional sample processing and by applying highly sensitive liquid waveguide spectrophotometry to the measurements of oxidized or acid-extracted phosphate from TPP and PIP, respectively. The oxidation of TPP was performed by a chemical wet oxidation method using 3% potassium persulfate. The acid extraction of PIP was initially carried out based on the conventional extraction methodology, which requires 1M HCl, followed by the procedure for decreasing acidity. While the conventional procedure for acid removal requires a ten-fold dilution of the 1M HCl extract with purified water, the improved procedure proposed in this study uses 8M NaOH solution for neutralizing 1M HCl extract in order to reduce the dilution effect. An experiment for comparing the absorbances of the phosphate standard dissolved in 0.1M HCl and of that dissolved in a neutralized solution [1M HCl: 8M NaOH=8:1 (v:v)] exhibited a higher absorbance in the neutralized solution. This indicated that the improved procedure completely removed the acid effect, which reduces the sensitivity of the phosphate measurement. Application to an ultraoligotrophic water sample showed that the TPP concentration in a 1075mL-filtered sample was 8.4nM with a coefficient of variation (CV) of 4.3% and the PIP concentration in a 2300mL-filtered sample was 1.3nM with a CV of 6.1%. Based on the detection limit (3nM) of the sensitive phosphate measurement and the ambient TPP and PIP concentrations of the ultraoligotrophic water, the minimum filtration volumes required for the detection of TPP and PIP were estimated to be 15 and 52mL, respectively.
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Affiliation(s)
- Makoto Ehama
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo 108-8477, Japan.
| | - Fuminori Hashihama
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo 108-8477, Japan
| | - Shinko Kinouchi
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo 108-8477, Japan
| | - Jota Kanda
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo 108-8477, Japan
| | - Hiroaki Saito
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8564, Japan
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Shiozaki T, Ijichi M, Isobe K, Hashihama F, Nakamura KI, Ehama M, Hayashizaki KI, Takahashi K, Hamasaki K, Furuya K. Nitrification and its influence on biogeochemical cycles from the equatorial Pacific to the Arctic Ocean. ISME J 2016; 10:2184-97. [PMID: 26918664 PMCID: PMC4989309 DOI: 10.1038/ismej.2016.18] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 01/03/2016] [Accepted: 01/05/2016] [Indexed: 11/29/2022]
Abstract
We examined nitrification in the euphotic zone, its impact on the nitrogen cycles, and the controlling factors along a 7500 km transect from the equatorial Pacific Ocean to the Arctic Ocean. Ammonia oxidation occurred in the euphotic zone at most of the stations. The gene and transcript abundances for ammonia oxidation indicated that the shallow clade archaea were the major ammonia oxidizers throughout the study regions. Ammonia oxidation accounted for up to 87.4% (average 55.6%) of the rate of nitrate assimilation in the subtropical oligotrophic region. However, in the shallow Bering and Chukchi sea shelves (bottom ⩽67 m), the percentage was small (0–4.74%) because ammonia oxidation and the abundance of ammonia oxidizers were low, the light environment being one possible explanation for the low activity. With the exception of the shallow bottom stations, depth-integrated ammonia oxidation was positively correlated with depth-integrated primary production. Ammonia oxidation was low in the high-nutrient low-chlorophyll subarctic region and high in the Bering Sea Green Belt, and primary production in both was influenced by micronutrient supply. An ammonium kinetics experiment demonstrated that ammonia oxidation did not increase significantly with the addition of 31–1560 nm ammonium at most stations except in the Bering Sea Green Belt. Thus, the relationship between ammonia oxidation and primary production does not simply indicate that ammonia oxidation increased with ammonium supply through decomposition of organic matter produced by primary production but that ammonia oxidation might also be controlled by micronutrient availability as with primary production.
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Affiliation(s)
- Takuhei Shiozaki
- Department of Marine Ecosystem Dynamics, Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan
| | - Minoru Ijichi
- Department of Marine Ecosystem Dynamics, Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan
| | - Kazuo Isobe
- Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Fuminori Hashihama
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Ken-Ichi Nakamura
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Makoto Ehama
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | | | - Kazutaka Takahashi
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Koji Hamasaki
- Department of Marine Ecosystem Dynamics, Atmosphere and Ocean Research Institute, The University of Tokyo, Chiba, Japan
| | - Ken Furuya
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
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Hashihama F, Kanda J, Tauchi A, Kodama T, Saito H, Furuya K. Liquid waveguide spectrophotometric measurement of nanomolar ammonium in seawater based on the indophenol reaction with o-phenylphenol (OPP). Talanta 2015; 143:374-380. [PMID: 26078173 DOI: 10.1016/j.talanta.2015.05.007] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 04/29/2015] [Accepted: 05/02/2015] [Indexed: 10/23/2022]
Abstract
We describe a highly sensitive colorimetric method for the determination of nanomolar concentrations of ammonium in seawater based on the indophenol reaction with o-phenylphenol [(1,1'-biphenyl)-2-ol, abbreviated as OPP]. OPP is available as non-toxic, stable flaky crystals with no caustic odor and has some advantages over phenol in practical use. The method was established by using a gas-segmented continuous flow analyzer equipped with two types of long path liquid waveguide capillary cell, LWCCs (100 cm and 200 cm) and an UltraPath (200 cm), which have inner diameters of 0.55 mm and 2 mm, respectively. The reagent concentrations, flow rates of the pumping tubes, and reaction path and temperature were determined on the basis of a manual indophenol blue method with OPP (Kanda, Water Res. 29 (1995) 2746-2750). The sample mixed with reagents that form indophenol blue dye was measured at 670 nm. Aged subtropical surface water was used as a blank, a matrix of standards, and the carrier. The detection limits of the analytical systems with a 100 cm LWCC, a 200 cm LWCC, and a 200 cm UltraPath were 6, 4, and 4 nM, respectively. These systems had high precision (<4% at 100 nM) and a linear dynamic range up to 200 nM. Non-linear baseline drift did not occur when using the UltraPath system. This is due to the elimination of cell clogging because of the larger inner diameter of the UltraPath compared to the LWCCs. The UltraPath system is thus more suitable for long-term measurements compared with the LWCC systems. The results of the proposed sensitive colorimetry and a conventional colorimetry for the determination of seawater samples showed no significant difference. The proposed analytical systems were applied to underway surface monitoring and vertical observation in the oligotrophic South Pacific.
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Affiliation(s)
- Fuminori Hashihama
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo 108-8477, Japan.
| | - Jota Kanda
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo 108-8477, Japan
| | - Ami Tauchi
- Department of Ocean Sciences, Tokyo University of Marine Science and Technology, Konan, Minato, Tokyo 108-8477, Japan
| | - Taketoshi Kodama
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi, Bunkyo, Tokyo 113-8657, Japan
| | - Hiroaki Saito
- Atmosphere and Ocean Research Institute, University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8564, Japan
| | - Ken Furuya
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, University of Tokyo, Yayoi, Bunkyo, Tokyo 113-8657, Japan
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Suzumura M, Hashihama F, Yamada N, Kinouchi S. Dissolved phosphorus pools and alkaline phosphatase activity in the euphotic zone of the Western north pacific ocean. Front Microbiol 2012; 3:99. [PMID: 22457661 PMCID: PMC3307022 DOI: 10.3389/fmicb.2012.00099] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2011] [Accepted: 02/28/2012] [Indexed: 12/01/2022] Open
Abstract
We measured pools of dissolved phosphorus (P), including dissolved inorganic P (DIP), dissolved organic P (DOP) and alkaline phosphatase (AP)-hydrolyzable labile DOP (L-DOP), and kinetic parameters of AP activity (APA) in the euphotic zone in the western North Pacific Ocean. Samples were collected from one coastal station in Sagami Bay, Japan, and three offshore stations between the North Pacific subtropical gyre (NPSG) and the Kuroshio region. Although DIP concentrations in the euphotic zone at all stations were equally low, around the nominal method detection limit of 20 nmol L(-1), chlorophyll a (Chl a) concentrations were one order of magnitude greater at the coastal station. DOP was the dominant P pool, comprising 62-92% of total dissolved P at and above the Chl a maximum layer (CML). L-DOP represented 22-39% of the total DOP at the offshore stations, whereas it accounted for a much higher proportion (about 85%) in the coastal surface layers. Significant correlations between maximum potential AP hydrolysis rates and DIP concentrations or bacterial cell abundance in the offshore euphotic zone suggest that major APA in the oligotrophic surface ocean is from bacterial activity and regulated largely by DIP availability. Although the range of maximum potential APA was comparable among the environmental conditions, the in situ hydrolysis rate of L-DOP in the coastal station was 10 times those in the offshore stations. L-DOP turnover time at the CML ranged from 4.5 days at the coastal station to 84.4 days in the NPSG. The ratio of the APA half-saturation constant to the ambient L-DOP concentration decreased markedly from the NPSG to the coastal station. There were substantial differences in the rate and efficiency of DOP remineralization and its contribution as the potential P source between the low-phosphate/high-biomass coastal ecosystem and the low-phosphate/low biomass oligotrophic ocean.
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Affiliation(s)
- Masahiro Suzumura
- Research Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and TechnologyTsukuba, Japan
| | - Fuminori Hashihama
- Department of Ocean Sciences, Tokyo University of Marine Science and TechnologyMinato-ku, Tokyo, Japan
| | - Namiha Yamada
- Research Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and TechnologyTsukuba, Japan
| | - Shinko Kinouchi
- Department of Ocean Sciences, Tokyo University of Marine Science and TechnologyMinato-ku, Tokyo, Japan
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Kodama T, Furuya K, Hashihama F, Takeda S, Kanda J. Occurrence of rain-origin nitrate patches at the nutrient-depleted surface in the East China Sea and the Philippine Sea during summer. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jc006814] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [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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