Marine Chemistry最新文献

{"title":"Characterization of polysulfides (Sx2−) in seawater euxinic conditions by electroanalytical methods","authors":"Sarah Mateša ,&nbsp;Marija Marguš ,&nbsp;Suzana Šegota ,&nbsp;Irena Ciglenečki","doi":"10.1016/j.marchem.2024.104398","DOIUrl":"https://doi.org/10.1016/j.marchem.2024.104398","url":null,"abstract":"<div><p>Polysulfides (S_x²⁻) are important reduced sulfur species (RSS) that play a role in numerous environmental processes. A sound analytical method for the measurement of S_x²⁻ in euxinic waters is lacking. In this work, differential pulse voltammetry (DPV) at the Hg electrode was used to measure the presence of S_x²⁻ in a model seawater solution and an euxinic marine lake (Rogoznica Lake - RL Croatia), in which the concentration of RSS, mainly HS⁻, varies between 100 and 4000 μM. In the DPV, an adsorption phenomenon associated with S_x²⁻ reduction on Hg produces a characteristic current minimum at −1.0 V (vs. Ag/AgCl), the magnitude of which is proportional to the concentration of polysulfidic sulfur.</p><p>The DPV current minima were recorded in the model solution K₂S_x NaCl/NaHCO₃ (pH ∼ 8.2) in a concentration range from 10 to 100 μM of polysulfidic sulfur. Total RSS was measured by cyclic voltammetry, and sampled DC voltammetry showed the ratio between HS⁻ and S⁰ within the S_x²⁻. Using the same methodology, the presence of S_x²⁻ below the chemocline enriched by photoptrophic sulfur bacteria was measured in the euxinic layer of RL at concentrations of up to 70 μM of polysulfidic sulfur. The results suggest that euxinic RL samples can be considered as polydisperse solutions of S⁰ or of S-rich compounds that can change their physicochemical properties and speciation during sample manipulation. These changes can be detected by electrochemistry. Atomic force microscopy proved the release of bacterial cellular S⁰ during the acidification and purging step in the electrochemical measurements, which contributed to the voltammetric RSS signal.</p></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"262 ","pages":"Article 104398"},"PeriodicalIF":3.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140950573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Microbial interactions with microplastics: Insights into the plastic carbon cycle in the ocean","authors":"Kai Ziervogel ,&nbsp;Sierra Kehoe ,&nbsp;Astrid Zapata De Jesus ,&nbsp;Alireza Saidi-Mehrabad ,&nbsp;Miriam Robertson ,&nbsp;Ariana Patterson ,&nbsp;Aron Stubbins","doi":"10.1016/j.marchem.2024.104395","DOIUrl":"10.1016/j.marchem.2024.104395","url":null,"abstract":"<div><p>The fate of microplastics (MPs) in the ocean is mostly driven by (i) photo-oxidation to smaller particles and dissolved constituents, which fuel the dissolved organic carbon pool (plastic-derived DOC, pDOC), and (ii) interactions with organic matter forming sinking aggregates (marine plastic snow). Two separate laboratory experiments were conducted to investigate the two pathways of MPs. In the first experiment, we measured potential rates of microbial pDOC utilization in bottle incubations over 15 days with microbial assemblages from coastal and offshore waters. Microbial utilization of pDOC was more efficient in the coastal (72% bioreactive pDOC) compared with the offshore experiment (32% bioreactive pDOC) 15 days. Changes in bacterial cell abundance and extracellular enzyme activities (glucosidase, peptidase, esterases) indicated that a fraction of pDOC was repackaged into microbial exopolymeric substances (EPS), stimulating growth of known EPS degrading bacteria within the phyla Verrucomicrobiota and Planctomycetota. Microbial EPS likely also played a key role in our second experiment that showed the formation of marine plastic snow in roller tanks with cultured cells of <em>Emiliana huxleyi</em> but not with cells of an <em>Isocrysis</em> sp. culture. Average sinking velocities of marine plastic snow were a factor of 1.2 lower compared with marine snow without MPs. Both aggregate types showed reduced sinking velocities in a density stratified sinking column. Our results from the two experiments on (i) microbial utilization of pDOC and (ii) the formation and sinking of marine plastic snow indicate potential effects of plastic-derived compounds on microbial elemental cycles (i.e., pDOC repackaged into EPS) with consequences for the efficiency of the biological carbon pump (i.e., marine plastic snow reduces carbon export) and the fate of plastic-derived compounds in the ocean.</p></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"262 ","pages":"Article 104395"},"PeriodicalIF":3.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140787065","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Biogeochemistry of dissolved trace metals in the Bay of Bengal","authors":"Idha Yulia Ikhsani ,&nbsp;Kuo Hong Wong ,&nbsp;Taejin Kim ,&nbsp;Asami S. Mashio ,&nbsp;Kazuhiro Norisuye ,&nbsp;Hajime Obata","doi":"10.1016/j.marchem.2024.104394","DOIUrl":"10.1016/j.marchem.2024.104394","url":null,"abstract":"<div><p>The pronounced seasonal variation over the Bay of Bengal affects trace metals concentration and distribution. Trace metals distribution in the Bay of Bengal has been best characterized during spring and fall intermonsoon, while limited studies were conducted during the southwest monsoon. This study reports the full-depth profiles of trace metals, including dissolved iron, manganese, lead, cadmium, copper, and zinc (Fe, Mn, Pb, Cd, Cu, and Zn) in the Bay of Bengal (BoB) during southwest monsoon, from July to August 2013. At coastal and ocean scales, transect observations covering the entire water depth provided a comprehensive picture of the circulation and biogeochemical cycles of these elements in seawater during the southwest monsoon. Water samples were obtained from one station in the northeastern Indian Ocean (NR-1) and from three shallow coastal stations with maximum depths &lt;60 m (BA-1, BA-3, and BA-5), as well as from three offshore stations with maximum depths exceeding 2000 m (MY-7, MY-9, and MY-11). In the surface layer (5 m depth), the trace metal concentrations at the shallow near-coastal station BA-5 were higher than those at the ocean station NR-1. Surface trace metal concentrations in offshore regions encompassing stations MY-11, MY-9, and MY-7 were relatively higher than those reported for other seasons in a similar salinity region, indicating seasonal variation associated with freshwater intrusion and coastal-derived input. Below the mixed layer depth, the trace metal/phosphate (P) ratio was higher than that previously reported in the eastern Indian Ocean, suggesting an input from continental margins and mildly reducing sediments, particularly for Fe, Mn, and Cu. Moreover, at intermediate depths (190–800 m), where the North Indian Central Water (NICW) is the main water mass, the Cd/P ratio (0.55 ± 0.11 nmol/μmol) deviated from the global trend (∼0.3 nmol/μmol) owing to oxygen-deficient conditions. Intriguingly, at some stations, specifically MY-9 and MY-7, the intermediate dFe concentrations were relatively higher than those at station NR-1 at the same depth. Continental margin sediment, water mass movement, and ventilation may control the transport of Fe from locations with high Fe concentrations, including near the continental shelf (station MY-11 in this study) and the Andaman Sea.</p></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"262 ","pages":"Article 104394"},"PeriodicalIF":3.0,"publicationDate":"2024-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140792310","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigation of sorption behavior of 137Cs in a river–sea system boundary area after the Fukushima Dai-ichi nuclear power plant accident","authors":"Hyoe Takata ,&nbsp;Yoshifumi Wakiyama ,&nbsp;Toshihiro Wada ,&nbsp;Shigekazu Hirao ,&nbsp;Tatsuo Aono ,&nbsp;Takahiro Nakanishi ,&nbsp;Toshiharu Misonou ,&nbsp;Takehiko Shiribiki ,&nbsp;Michio Aoyama","doi":"10.1016/j.marchem.2024.104384","DOIUrl":"https://doi.org/10.1016/j.marchem.2024.104384","url":null,"abstract":"<div><p>The radiocesium (¹³⁷Cs) distribution between dissolved and particulate phases was examined in river water and coastal seawater as a function of the ¹³⁷Cs sorption behavior on suspended particles. Dissolved ¹³⁷Cs activity concentrations in the Tomioka River (salinity &lt;0.1), about 10 km south of Fukushima Dai-ichi Nuclear Power Plant, and in coastal seawater at Tomioka fishery port (salinity &gt;30), Fukushima Prefecture, from June 2019 to October 2021 were 3.6–20 Bq/m³ (geometric mean 11 Bq/m³) and 2.4–86 Bq/m³ (13 Bq/m³), respectively. Although the suspended particle concentration was lower in the river than in seawater, the mean ¹³⁷Cs activity on suspended particles was 11,000 Bq/kg-dry in the river versus 3200 Bq/kg-dry in seawater. Proportions of ion-exchangeable, organically bound, and refractory fractions of ¹³⁷Cs on suspended particles were determined by sequential extraction. The ion-exchangeable fraction accounted for 0.3–2.0% (average: 1.2%) and 0.4–1.3% (0.8%) at the river and port sites, respectively. The organically bound fraction accounted for 0.3–4.8% (1.8%) and 0.1–5.5% (2.1%) at the river and port sites, respectively. In both areas, the refractory fraction accounted for &gt;90% of ¹³⁷Cs. Therefore, the small labile ¹³⁷Cs fraction on suspended particles in coastal seawater indicates that the mobility of ¹³⁷Cs to marine biota is quite low.</p></div><div><h3>Synopsis</h3><p>This study is the first to examine radiocesium sorption forms on suspended particles in coastal seawater near the Fukushima Dai-ichi Nuclear Power Plant. It suggests immobility of ¹³⁷Cs in suspended particles being incorporated to marine biota.</p></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"262 ","pages":"Article 104384"},"PeriodicalIF":3.0,"publicationDate":"2024-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140619089","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A half-cell reaction approach for pH calculation using a solid-state chloride ion-selective electrode with a hydrogen ion-selective ion-sensitive field effect transistor","authors":"S. Fisher Gonski ,&nbsp;George W. Luther III ,&nbsp;Amanda L. Kelley ,&nbsp;Todd R. Martz ,&nbsp;Elliott G. Roberts ,&nbsp;Xinyu Li ,&nbsp;Bo Dong ,&nbsp;Jordan A. Watson ,&nbsp;Taylor S. Wirth ,&nbsp;Najid Hussain ,&nbsp;Randy J. Feris Serrano ,&nbsp;Edward Hale ,&nbsp;Wei-Jun Cai","doi":"10.1016/j.marchem.2024.104373","DOIUrl":"10.1016/j.marchem.2024.104373","url":null,"abstract":"<div><p>Here, we explicitly define a half-cell reaction approach for pH calculation using the electrode couple comprised of the solid-state chloride ion-selective electrode (Cl-ISE) as the reference electrode and the hydrogen ion-selective ion-sensitive field effect transistor (ISFET) of the Honeywell Durafet as the hydrogen ion <span><math><mfenced><msup><mi>H</mi><mo>+</mo></msup></mfenced></math></span>-sensitive measuring or working electrode. This new approach splits and isolates the independent responses of the Cl-ISE to the chloride ion <span><math><mfenced><msup><mi>Cl</mi><mo>−</mo></msup></mfenced></math></span> (and salinity) and the ISFET to <span><math><msup><mi>H</mi><mo>+</mo></msup></math></span> (and pH), and calculates pH directly on the total scale <span><math><mfenced><msubsup><mi>pH</mi><mtext>total</mtext><mi>EXT</mi></msubsup></mfenced></math></span> in molinity (mol (kg-soln)⁻¹) concentration units. We further apply and compare <span><math><msubsup><mi>pH</mi><mtext>total</mtext><mi>EXT</mi></msubsup></math></span> calculated using the half-cell and the existing complete cell reaction (defined by <span>Martz et al. (2010)</span>) approaches using measurements from two SeapHOx sensors deployed in a test tank. Salinity (on the Practical Salinity Scale) and pH oscillated between 1 and 31 and 6.9 and 8.1, respectively, over a six-day period.</p><p>In contrast to established Sensor Best Practices, we employ a new calibration method where the calibration of raw pH sensor timeseries are split out <em>as needed</em> according to salinity. When doing this, <span><math><msubsup><mi>pH</mi><mtext>total</mtext><mi>EXT</mi></msubsup></math></span> had root-mean squared errors ranging between ±0.0026 and ±0.0168 pH calculated using both reaction approaches relative to <span><math><msub><mi>pH</mi><mtext>total</mtext></msub></math></span> of the discrete bottle samples <span><math><mfenced><msubsup><mi>pH</mi><mtext>total</mtext><mtext>disc</mtext></msubsup></mfenced></math></span>. Our results further demonstrate the rapid response of the Cl-ISE reference to variable salinity with changes up to ±12 (30 min)⁻¹. Final calculated <span><math><msubsup><mi>pH</mi><mtext>total</mtext><mi>EXT</mi></msubsup></math></span> were ≤±0.012 pH when compared to <span><math><msubsup><mi>pH</mi><mtext>total</mtext><mtext>disc</mtext></msubsup></math></span> following salinity dilution or concentration. These results are notably in contrast to those of the few <em>in situ</em> field deployments over similar environmental conditions that demonstrated <span><math><msubsup><mi>pH</mi><mtext>total</mtext><mi>EXT</mi></msubsup></math></span> calculated using the Cl-ISE as the reference electrode had larger uncertainty in nearshore waters. Therefore, additional work beyond the correction of variable temperature and salinity conditions in <span><math><mi>pH</mi></math></span> calculation using the Cl-ISE is needed to examine the effects of","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"261 ","pages":"Article 104373"},"PeriodicalIF":3.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0304420324000240/pdfft?md5=955bdbc3f8b8019eae41388e29752115&pid=1-s2.0-S0304420324000240-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140127146","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing sedimentary black carbon in the Pearl River Estuary, Southern China","authors":"Xinyi Liu ,&nbsp;Yali Li ,&nbsp;Tian Lin ,&nbsp;Nairong Guo ,&nbsp;Jiawen Yuan ,&nbsp;Ying Yang ,&nbsp;Wei-dong Zhai","doi":"10.1016/j.marchem.2024.104383","DOIUrl":"https://doi.org/10.1016/j.marchem.2024.104383","url":null,"abstract":"<div><p>Sedimentary black carbon in coastal regions plays an important role in global carbon cycles due to its refractory nature in sediments. In this study, we conducted the first comprehensive investigation on black carbon (BC) in surface sediments of the Pearl River Estuary (PRE), a large tropical estuary system in China. We used two different analytical methods: IMPROVE-A thermal optical reflectance (TOR) and chemothermal oxidation (CTO-375) to constrain the distribution, and TOR can further constrain the composition (i.e., char and soot). The BC concentration determined by the TOR method (BC_TOR) ranged from 0.07 to 7.13 mg/g, with char and soot contents ranging from 0.04 to 6.98 mg/g and 0.03–0.43 mg/g, respectively. The BC concentrations measured by the CTO-375 method (BC_CTO) ranged from 0.27 to 1.88 mg/g. Char was the predominant constituent (87%) of sedimentary BC_TOR in the PRE. Both char and soot had higher concentrations locating near the outlets and on the Shenzhen coast, indicating that they were sourced through direct fluvial transport and surface runoff. Soot particles were transported farther from fluvial sources than char particles. We estimated that the burial flux of BC_TOR in the PRE sediments was 2.97 ± 1.61 mg/cm²/yr, acting as an important sink of BC. This study implies that large river estuaries are hotspots for BC burial, sinking a large amount of organic carbon from terrestrial reservoirs.</p></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"261 ","pages":"Article 104383"},"PeriodicalIF":3.0,"publicationDate":"2024-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140543378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tracing the contributions of different nitrate sources associated with submarine groundwater discharge in coastal seawaters off Jeju Island, Korea","authors":"Jihyun Park ,&nbsp;Guebuem Kim ,&nbsp;Tae-Hoon Kim ,&nbsp;TaeKeun Rho ,&nbsp;Purena Son","doi":"10.1016/j.marchem.2024.104382","DOIUrl":"10.1016/j.marchem.2024.104382","url":null,"abstract":"<div><p>We measured the concentrations of dissolved inorganic nutrients and the dual isotopic composition of nitrate (δ¹⁵N-NO₃⁻ and δ¹⁸O-NO₃⁻) in coastal waters off Jeju, a volcanic island in Korea, to trace its main sources. Sampling of seawater and fresh groundwater was conducted in four different coastal areas of Jeju Island: Haengwon (HW), Pyoseon (PS), Ilgwa (IG), and Sagye (SG) in May 2020 and 2021. The significant negative correlations between NO₃⁻ and salinity in the four areas indicate that the main source of NO₃⁻ is fresh submarine groundwater discharge (FSGD), with the extrapolated fresh groundwater endmember values ranging from 170 to 300 μM (δ¹⁵N-NO₃⁻: 4.1–10.8 and δ¹⁸O-NO₃⁻: 1.7–6.4). The actual sources of SGD-driven NO₃⁻ in these coastal waters were determined using a bi-plot diagram (δ¹⁵N-NO₃⁻ vs. δ¹⁸O-NO₃⁻) and a Bayesian stable isotope mixing model (MixSIAR). The results showed that, besides the background contribution from open-ocean waters, the main sources of NO₃⁻ in HW were fertilizer (69 ± 5%) and manure and sewage (24 ± 7%) and those in PS, IG, and SG were manure and sewage (PS: 53 ± 11%, IG: 57 ± 12%, SG: 63 ± 13%) and fertilizer (PS: 27 ± 8%, IG: 24 ± 5%, SG: 22 ± 5%). Our extrapolation approach for NO₃⁻ dual isotopes provides a better way to evaluate the main sources of NO₃⁻ in coastal waters off volcanic islands where SGD-driven NO₃⁻ is significant, but its actual source groundwater cannot be located.</p></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"261 ","pages":"Article 104382"},"PeriodicalIF":3.0,"publicationDate":"2024-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140182347","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Distributions of zirconium, hafnium, and niobium in the Indian Ocean: Influence of lithogenic sources on incompatible elements","authors":"Ryuta Ueki,&nbsp;Linjie Zheng,&nbsp;Shotaro Takano,&nbsp;Yoshiki Sohrin","doi":"10.1016/j.marchem.2024.104365","DOIUrl":"10.1016/j.marchem.2024.104365","url":null,"abstract":"<div><p>Zirconium (Zr), hafnium (Hf), and niobium (Nb) are incompatible elements concentrated on the granitic continent. They are trace elements at the pmol/kg level in seawater and are considered potential tracers for water masses. However, data on the distribution of the three elements in modern oceans are limited, particularly in the Indian Ocean. Here, we report the first basin-scale sectional distributions of the three elements at 11 stations from 62°S to 17°N in the Indian Ocean and Indian sector of the Southern Ocean. Unfiltered and filtered seawater samples were stored in low-density polyethylene (LDPE) bottles for approximately 12 years and used to determine the concentrations of the total dissolvable (td) and dissolved (d) fractions, respectively. We found that the absorption percentages on the bottle wall were &lt;10% for Zr, Hf, and Nb. The concentration ranges of dZr, dHf, and dNb in the Indian Ocean and Indian sector of the Southern Ocean were 8–348, 0.06–1.06, and 1.3–4.3 pmol/kg, respectively. The labile particulate (lp) concentration was obtained as the difference between td and d, which was less than the detection limit in most samples. The concentrations of dZr, dHf, and dNb in surface water were high in the Bay of Bengal and Arabian Sea, and the concentrations of Zr and Hf in the deep waters of the Indian Ocean were higher than those in the deep waters of the North Pacific Ocean in a similar manner with dAl. These results indicate that the Indian Ocean has strong influences of lithogenic sources for Al, Zr, and Hf. The dZr/dHf mole ratio characterized water masses in the Indian Ocean and increased in the following order: Atlantic Ocean &lt; Indian Ocean &lt; Pacific Ocean due to the preferential removal of dHf over dZr during thermohaline circulation and the local input of dZr and dHf in the Indian Ocean. Thus, we propose that the dZr/dHf ratio is a potential tracer for global ocean circulation.</p></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"260 ","pages":"Article 104365"},"PeriodicalIF":3.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0304420324000161/pdfft?md5=92afd9a4a3380757b101d4418e8974ae&pid=1-s2.0-S0304420324000161-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139949474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dissolved zinc in the western Bering Sea and near Kamchatka Strait: A coastal source and transport to the subarctic Pacific","authors":"Kuo Hong Wong ,&nbsp;Hajime Obata ,&nbsp;Taejin Kim ,&nbsp;Hirofumi Tazoe ,&nbsp;Asami S. Mashio ,&nbsp;Hiroshi Hasegawa ,&nbsp;Jun Nishioka","doi":"10.1016/j.marchem.2024.104375","DOIUrl":"10.1016/j.marchem.2024.104375","url":null,"abstract":"<div><p>Dissolved zinc (dZn) is an important micronutrient for phytoplankton in the ocean. In high nutrient low chlorophyll (HNLC) regions like the western Bering Sea basin, Zn deficiency might induce shifts in phytoplankton community species. In this study, we presented the first dZn distribution data in the western Bering Sea and near Kamchatka Strait and investigated the biogeochemical cycles of Zn in these regions. Although dZn and silicate (Si) show similar distribution patterns in the global ocean, there is an excess of dZn relative to Si in the intermediate waters of our study region, similar to that previously observed in the subarctic Pacific. The uptake and subsequent regeneration patterns of dZn, Si, and phosphate (PO₄) in the study region reveal that excess dZn in the subarctic Pacific is not derived from biogenic processes, because the uptake and regeneration ratios of dZn to phosphate (PO₄) cannot account for the additional dZn supplied. Instead, our analyses indicate that a significant proportion of dZn in the region originates from the non-reductive release from shelf sediments. dZn concentrations were elevated in coastal regions at the same isopycnal where excess dZn was observed in the subarctic Pacific, suggesting that some of these sediment-derived dZn were transported to the subarctic Pacific.</p></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"260 ","pages":"Article 104375"},"PeriodicalIF":3.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140127159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Low-blank method for the offline batch analysis of the low concentration of dissolved lead in natural waters and its application to natural waters, including the tropical Northwest Pacific Ocean","authors":"Shuo Jiang ,&nbsp;Jing Zhang ,&nbsp;Zheng Bo Liu ,&nbsp;Han Su","doi":"10.1016/j.marchem.2024.104374","DOIUrl":"https://doi.org/10.1016/j.marchem.2024.104374","url":null,"abstract":"<div><p>In this study, Presep® PolyChelate resin was utilized for the offline batch extraction process and then combined with the isotope dilution method for the analysis of low concentrations of dissolved lead (Pb) in freshwater and seawater. The application of Presep® PolyChelate resin further lowered the procedural blank by reducing the amount of resin beads and buffer solution that were added with an 8-fold preconcentration. The adsorption and elution times were shortened to 2 d and 30 min, respectively, and &gt; 85% recovery was achieved. The total procedural blank and detection limit were 0.2 ± 0.1 pmol/kg and 0.2 pmol/kg, respectively. The accuracy of this method was also verified using GEOTRACES intercalibration SAFe seawaters, with concentrations of 48.0 ± 0.5 pmol/kg (<em>n</em> = 3) and 27.0 ± 0.7 pmol/kg (n = 3) observed for SAFE S and D2, respectively. Full-depth profiles of dissolved Pb concentrations collected during the 2016 tropical Northwest Pacific Ocean cruise were analyzed. The dissolved Pb concentration increased from 30 pmol/kg at the surface to 50 pmol/kg at the subsurface and it then decreased to 8–9 pmol/kg in the bottom waters.</p></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"260 ","pages":"Article 104374"},"PeriodicalIF":3.0,"publicationDate":"2024-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140122886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}