Marine Chemistry最新文献_第5页

MNPs in marine environment: Sources, distribution, trophic transfer, toxicity, fate and the remediating role of epiplastic syntrophic microbial consortia (Biofilms) 海洋环境中MNPs的来源、分布、营养转移、毒性、命运和修复作用

IF 2.5 3区地球科学 Q2 CHEMISTRY, MULTIDISCIPLINARY

Marine Chemistry

Pub Date : 2025-08-27 DOI: 10.1016/j.marchem.2025.104553

Smarto Basak , Amit Kumar Dixit , Ranjit Kumar Dey , Gajji Babu

This review focuses on plastic pollution, which has emerged as an urgent environmental issue with microplastics (MiPs) and nanoplastics (NaPs) being widespread contaminants in marine ecosystem. These particles pose serious ecological and public health risks due to their ability to bioaccumulate and vertically transfer through the food chain rapidly. Ingestion of MiPs and NaPs (MNPs) causes harmful physiological and reproductive effects, threatening the stability and integrity of marine food chains. This review summarizes the sources, distribution, trophic transfer, toxicity and fate of MNPs involving the marine ecosystem. Microbial communities have displayed potential as remediating agent for MNPs; though the processes involved in NaP degradation remain poorly understood, highlighting the need for further research. The distinctive properties of NaPs complicate their interactions with microbial communities, pointing to the necessity for focused studies on their biodegradation pathways. This review advocates for a holistic strategy that employs epiplastic syntrophic microbial consortia (Biofilm) as bioremediating agents, as their interactions may enhance breakdown of MNPs in marine setting. Future research should aim to clarify the relationships between microbial consortia and NaPs, identifying ideal conditions that foster microbial growth and activity on these NaPs. This review will be helpful for innovating effective management strategies to reduce the impacts of these established pollutants; ultimately, increasing our understanding of MNPs in marine environment, which is critical for shaping policies that safeguards the future of marine ecosystem and public health. Tackling plastic pollution requires a collaborative approach across all scientific fields, emphasizing the gravity of this global challenge.

微塑料和纳米塑料是海洋生态系统中广泛存在的污染物，塑料污染已成为一个紧迫的环境问题。由于这些颗粒具有生物积累和通过食物链迅速垂直转移的能力，它们构成严重的生态和公共卫生风险。摄入mip和nap （MNPs）会造成有害的生理和生殖影响，威胁到海洋食物链的稳定性和完整性。本文综述了涉及海洋生态系统的MNPs的来源、分布、营养转移、毒性和命运。微生物群落已显示出作为MNPs修复剂的潜力；尽管对NaP降解过程的了解仍然很少，这表明需要进一步的研究。nap的独特特性使其与微生物群落的相互作用复杂化，这表明有必要对其生物降解途径进行重点研究。这篇综述提倡采用一种整体的策略，采用表观共生微生物联盟（生物膜）作为生物修复剂，因为它们的相互作用可能会增强海洋环境中MNPs的分解。未来的研究应旨在阐明微生物群落与nap之间的关系，确定促进这些nap上微生物生长和活性的理想条件。这将有助于创新有效的管理策略，以减少这些既定污染物的影响；最终，增进我们对海洋环境中的跨国企业的了解，这对于制定保障海洋生态系统和公众健康未来的政策至关重要。解决塑料污染需要所有科学领域的合作，强调这一全球挑战的严重性。

{"title":"MNPs in marine environment: Sources, distribution, trophic transfer, toxicity, fate and the remediating role of epiplastic syntrophic microbial consortia (Biofilms)","authors":"Smarto Basak , Amit Kumar Dixit , Ranjit Kumar Dey , Gajji Babu","doi":"10.1016/j.marchem.2025.104553","DOIUrl":"10.1016/j.marchem.2025.104553","url":null,"abstract":"<div><div>This review focuses on plastic pollution, which has emerged as an urgent environmental issue with microplastics (MiPs) and nanoplastics (NaPs) being widespread contaminants in marine ecosystem. These particles pose serious ecological and public health risks due to their ability to bioaccumulate and vertically transfer through the food chain rapidly. Ingestion of MiPs and NaPs (MNPs) causes harmful physiological and reproductive effects, threatening the stability and integrity of marine food chains. This review summarizes the sources, distribution, trophic transfer, toxicity and fate of MNPs involving the marine ecosystem. Microbial communities have displayed potential as remediating agent for MNPs; though the processes involved in NaP degradation remain poorly understood, highlighting the need for further research. The distinctive properties of NaPs complicate their interactions with microbial communities, pointing to the necessity for focused studies on their biodegradation pathways. This review advocates for a holistic strategy that employs epiplastic syntrophic microbial consortia (Biofilm) as bioremediating agents, as their interactions may enhance breakdown of MNPs in marine setting. Future research should aim to clarify the relationships between microbial consortia and NaPs, identifying ideal conditions that foster microbial growth and activity on these NaPs. This review will be helpful for innovating effective management strategies to reduce the impacts of these established pollutants; ultimately, increasing our understanding of MNPs in marine environment, which is critical for shaping policies that safeguards the future of marine ecosystem and public health. Tackling plastic pollution requires a collaborative approach across all scientific fields, emphasizing the gravity of this global challenge.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"273 ","pages":"Article 104553"},"PeriodicalIF":2.5,"publicationDate":"2025-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144933632","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}

引用次数: 0

pHT measurements of TRIS buffer solutions in an artificial seawater matrix in the salinity range 5–40 and temperature range 5–40 °C. Part 1: Measurements and data fitting TRIS缓冲溶液在人工海水基质中盐度范围5-40，温度范围5-40℃的pHT测量。第1部分：测量和数据拟合

IF 2.5 3区地球科学 Q2 CHEMISTRY, MULTIDISCIPLINARY

Marine Chemistry

Pub Date : 2025-08-26 DOI: 10.1016/j.marchem.2025.104551

Gaëlle Capitaine , Rieke Schäfer , Frank Bastkowski , Daniela Stoica , Olivier Pellegrino , Raquel Quendera , Eric P. Achterberg , Thibaut Wagener , Simon L. Clegg , Steffen Seitz , Paola Fisicaro

Spectrophotometric measurements of seawater total pH (

p H_{T}

) contribute to the knowledge of the oceanic carbonate system, and hence to the assessment of the ocean carbon cycle and the monitoring of ocean acidification. Spectrophotometric measurements rely on the characterization of the indicator dye's second dissociation constant, obtained from measurements on solutions of known

p H_{T}

. Therefore, Harned cell potentiometric measurements were performed on equimolal TRIS buffers (i.e. buffers containing equal molalities of 2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIS, CAS reference number 77–86-1) and TRIS hydrochloride (TRIS.HCl)), made in an artificial seawater (ASW) matrix. Buffer solutions were prepared in an ASW matrix of nominal practical salinities from 5 to 40, and Harned cell measurements were performed on these solutions at temperatures from 5 °C to 40 °C. This provides, for the first time,

p H_{T}

values of ASW/TRIS buffers that are consistent for the entire ranges of salinity relevant for oceanographic measurements, and for a wide range of temperature. The work presented includes a comparison of results from three National Metrology Institutes to assess reproducibility, and provides a function allowing the calculation of equimolal ASW/TRIS buffers

p H_{T}

as a function of salinity, temperature and TRIS buffer molality. This function can be used to derive

p H_{T}

values for zero TRIS molality, thus representing a pure ASW (i.e. a chemical environment unaffected by the presence of TRIS and TRIS.HCl), and referring to a true

p H_{T}

scale. These values are needed for the characterization of the second dissociation constant of the dye with perspective of traceability to the International System of units.

海水总pH值（pHT）的分光光度测量有助于了解海洋碳酸盐系统，从而评估海洋碳循环和监测海洋酸化。分光光度法测量依赖于指示剂染料的第二解离常数的表征，从已知pHT溶液的测量中获得。因此，在等量TRIS缓冲液(即含有等量摩尔数的2-氨基-2-（羟甲基）-1,3-丙二醇（TRIS， CAS参考号77-86-1）和TRIS盐酸（TRIS）缓冲液（TRIS）上进行了Harned细胞电位测量。HCl))，在人工海水（ASW）基质中制成。缓冲溶液在标称实际盐度为5至40的ASW基质中制备，并在5°C至40°C的温度下对这些溶液进行Harned细胞测量。这首次提供了ASW/TRIS缓冲层的pHT值，该值与海洋测量相关的整个盐度范围和广泛的温度范围一致。介绍的工作包括对三个国家计量研究所的结果进行比较，以评估再现性，并提供了一个函数，允许计算等量ASW/TRIS缓冲液pHT作为盐度，温度和TRIS缓冲液摩尔浓度的函数。该函数可用于推导零TRIS质量浓度的pHT值，从而表示纯ASW（即不受TRIS和TRIS存在影响的化学环境）。HCl)，并参考真正的pHT刻度。从国际单位制追溯的角度来看，染料的第二解离常数的表征需要这些值。

{"title":"pHT measurements of TRIS buffer solutions in an artificial seawater matrix in the salinity range 5–40 and temperature range 5–40 °C. Part 1: Measurements and data fitting","authors":"Gaëlle Capitaine , Rieke Schäfer , Frank Bastkowski , Daniela Stoica , Olivier Pellegrino , Raquel Quendera , Eric P. Achterberg , Thibaut Wagener , Simon L. Clegg , Steffen Seitz , Paola Fisicaro","doi":"10.1016/j.marchem.2025.104551","DOIUrl":"10.1016/j.marchem.2025.104551","url":null,"abstract":"<div><div>Spectrophotometric measurements of seawater total pH (<span><math><mi>p</mi><msub><mi>H</mi><mi>T</mi></msub></math></span>) contribute to the knowledge of the oceanic carbonate system, and hence to the assessment of the ocean carbon cycle and the monitoring of ocean acidification. Spectrophotometric measurements rely on the characterization of the indicator dye's second dissociation constant, obtained from measurements on solutions of known <span><math><mi>p</mi><msub><mi>H</mi><mi>T</mi></msub></math></span>. Therefore, Harned cell potentiometric measurements were performed on equimolal TRIS buffers (i.e. buffers containing equal molalities of 2-amino-2-(hydroxymethyl)-1,3-propanediol (TRIS, CAS reference number 77–86-1) and TRIS hydrochloride (TRIS.HCl)), made in an artificial seawater (ASW) matrix. Buffer solutions were prepared in an ASW matrix of nominal practical salinities from 5 to 40, and Harned cell measurements were performed on these solutions at temperatures from 5 °C to 40 °C. This provides, for the first time, <span><math><mi>p</mi><msub><mi>H</mi><mi>T</mi></msub></math></span> values of ASW/TRIS buffers that are consistent for the entire ranges of salinity relevant for oceanographic measurements, and for a wide range of temperature. The work presented includes a comparison of results from three National Metrology Institutes to assess reproducibility, and provides a function allowing the calculation of equimolal ASW/TRIS buffers <span><math><mi>p</mi><msub><mi>H</mi><mi>T</mi></msub></math></span> as a function of salinity, temperature and TRIS buffer molality. This function can be used to derive <span><math><mi>p</mi><msub><mi>H</mi><mi>T</mi></msub></math></span> values for zero TRIS molality, thus representing a pure ASW (i.e. a chemical environment unaffected by the presence of TRIS and TRIS.HCl), and referring to a true <span><math><mi>p</mi><msub><mi>H</mi><mi>T</mi></msub></math></span> scale. These values are needed for the characterization of the second dissociation constant of the dye with perspective of traceability to the International System of units.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"273 ","pages":"Article 104551"},"PeriodicalIF":2.5,"publicationDate":"2025-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144933633","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}

引用次数: 0

Particulate iron seasonality between winter and spring in the open Southern Atlantic Ocean is primarily driven by non-biological processes 在开阔的南大西洋，颗粒铁在冬季和春季之间的季节性主要是由非生物过程驱动的

IF 2.5 3区地球科学 Q2 CHEMISTRY, MULTIDISCIPLINARY

Marine Chemistry

Pub Date : 2025-08-15 DOI: 10.1016/j.marchem.2025.104552

Antoine Ringard , Hélène Planquette , Thato Mtshali , Alakendra Roychoudhury , Eva Bucciarelli

In the open Southern Ocean, primary productivity is mainly driven by limiting concentrations of iron. However, limited available iron data during winter leave a gap in our understanding of how seasonality affects the iron cycle, and primary productivity. In this context, two cruises followed the same transect in the Atlantic sector of the Southern Ocean, from the SubTropical zone to the Antarctic zone, during spring and winter. This study aims to determine whether particulate iron concentrations showed seasonal changes, and to identify the processes driving these variations. Particulate iron ranged between 0.04–0.99 nM and 0.04–1.17 nM during spring and winter, respectively, with the lowest concentrations measured in surface waters. Overall, seasonality did not consistently affect total pFe distributions, and when differences existed, total pFe concentrations were higher in winter than in spring. Our findings indicate that biogenic particulate iron is higher in spring than in winter, and represents only a minor component of total pFe in surface waters during both seasons. Therefore, biological processes do not account for the observed seasonal changes in total pFe concentrations. At certain stations, higher pFe concentrations in winter relative to spring appear to be related to episodic external inputs of lithogenic particles, such as iron-rich dust deposition and inputs from the ACC. The authigenic fraction is the primary contributor to total pFe. These particles seem to be formed through the precipitation of dissolved iron derived from the dissolution of lithogenic particles or hydrothermal activity.

在开阔的南大洋，初级生产力主要受铁浓度限制的驱动。然而，有限的冬季铁数据使我们对季节性如何影响铁循环和初级生产力的理解存在空白。在这种情况下，在春季和冬季，两次巡航沿着南大洋大西洋部分的同一样带，从亚热带区到南极区。本研究旨在确定颗粒铁浓度是否表现出季节性变化，并确定驱动这些变化的过程。春季和冬季颗粒铁浓度分别在0.04 ~ 0.99 nM和0.04 ~ 1.17 nM之间，地表水中颗粒铁浓度最低。总体而言，季节对总pFe分布的影响并不一致，当存在差异时，冬季总pFe浓度高于春季。我们的研究结果表明，生物颗粒铁在春季高于冬季，并且在两个季节只占地表水总pFe的一小部分。因此，生物过程不能解释观测到的全氟化铁浓度的季节变化。在某些站点，冬季的pFe浓度高于春季，似乎与产岩颗粒的偶发性外部输入有关，例如富铁粉尘沉积和来自ACC的输入。自生部分是总pFe的主要贡献者。这些颗粒似乎是由成岩颗粒溶解或热液活动产生的溶解铁的沉淀形成的。

{"title":"Particulate iron seasonality between winter and spring in the open Southern Atlantic Ocean is primarily driven by non-biological processes","authors":"Antoine Ringard , Hélène Planquette , Thato Mtshali , Alakendra Roychoudhury , Eva Bucciarelli","doi":"10.1016/j.marchem.2025.104552","DOIUrl":"10.1016/j.marchem.2025.104552","url":null,"abstract":"<div><div>In the open Southern Ocean, primary productivity is mainly driven by limiting concentrations of iron. However, limited available iron data during winter leave a gap in our understanding of how seasonality affects the iron cycle, and primary productivity. In this context, two cruises followed the same transect in the Atlantic sector of the Southern Ocean, from the SubTropical zone to the Antarctic zone, during spring and winter. This study aims to determine whether particulate iron concentrations showed seasonal changes, and to identify the processes driving these variations. Particulate iron ranged between 0.04–0.99 nM and 0.04–1.17 nM during spring and winter, respectively, with the lowest concentrations measured in surface waters. Overall, seasonality did not consistently affect total pFe distributions, and when differences existed, total pFe concentrations were higher in winter than in spring. Our findings indicate that biogenic particulate iron is higher in spring than in winter, and represents only a minor component of total pFe in surface waters during both seasons. Therefore, biological processes do not account for the observed seasonal changes in total pFe concentrations. At certain stations, higher pFe concentrations in winter relative to spring appear to be related to episodic external inputs of lithogenic particles, such as iron-rich dust deposition and inputs from the ACC. The authigenic fraction is the primary contributor to total pFe. These particles seem to be formed through the precipitation of dissolved iron derived from the dissolution of lithogenic particles or hydrothermal activity.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"272 ","pages":"Article 104552"},"PeriodicalIF":2.5,"publicationDate":"2025-08-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144864876","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}

引用次数: 0

Responses of the dynamics of particulate organic matter to different track typhoons in coastal waters 沿海海域不同路径台风对颗粒物有机物动力学的响应

IF 2.5 3区地球科学 Q2 CHEMISTRY, MULTIDISCIPLINARY

Marine Chemistry

Pub Date : 2025-08-12 DOI: 10.1016/j.marchem.2025.104550

Chunqing Chen , Qibin Lao , Xin Zhou , Shangjun Cai , Sihai Liu , Fajin Chen

The impact of typhoons on marine biogeochemical processes depends on their intensity, track, and speed. However, how particulate organic matter (POM) dynamics respond to typhoons with distinct tracks remains poorly understood. This study investigated physicochemical parameters and stable isotopes of POM (δ¹³C-POC and δ¹⁵N-PN) through continuous observations (one cruise before the typhoon and four cruises after the typhoon, with a 5-day interval) in Zhanjiang Bay following two distinct track typhoons. During Typhoon Lionrock (landfall on the left side of the bay), onshore-wind stress drove high-salinity seawater intrusion, forming a strong salinity front in the bay that suppressed phytoplankton growth (Chl-a decreased by 80 %). In contrast, Typhoon Chaba (landfall on the right side of the bay) generated offshore-wind stress that resulted in weaker water mixing, while abundant terrestrial nutrient input promoted phytoplankton growth (Chl-a increased by two times in the 2nd and 4th cruises after the typhoon). Nevertheless, positive apparent oxygen utilization (AOU) values in the water column were observed after both typhoons, indicating strong decomposition of POM in Zhanjiang Bay. The strongest decomposition (over 80 %) for the two typhoons all occurred after 3 days of the typhoon landfall, and gradually decreased after 8 days of the typhoon landfall. The POM degraded after Typhoon Lionrock mainly originated from resuspended old POM, while from fresh POM (phytoplankton) after Typhoon Chaba. Additionally, the decomposition degree (56 %) induced by Lionrock was stronger than that induced by Chaba (44 %), suggesting that the typhoon landing on the left side of the bay are not conducive to marine carbon burial.

台风对海洋生物地球化学过程的影响取决于其强度、路径和速度。然而，颗粒有机物质（POM）动力学如何响应具有不同路径的台风仍然知之甚少。本文通过连续观测（台风前1次，台风后4次，间隔5 d），研究了湛江湾两次不同路径台风后POM的物理化学参数和稳定同位素（δ13C-POC和δ15N-PN）。台风“狮子石”（登陆于海湾左侧）期间，陆上风应力驱动高盐度海水入侵，在海湾形成强盐度锋，抑制浮游植物生长（Chl-a下降80%）。台风“查巴”（登陆海湾右侧）产生的近海风应力导致水体混合减弱，而丰富的陆地养分输入促进了浮游植物的生长（Chl-a在台风后的第2次和第4次巡航中增加了2倍）。但两次台风过后，湛江湾水体的表观氧利用率（AOU）均为正，表明POM在湛江湾分解强烈。两个台风的最强分解（80%以上）均发生在台风登陆3天后，8天后分解逐渐减弱。台风“狮子山”后降解的POM主要来源于重悬浮的旧POM，而台风“查巴”后降解的POM主要来源于新鲜的浮游植物。此外，“狮子岩”的分解程度（56%）比“查巴”的分解程度（44%）更强，说明登陆海湾左侧的台风不利于海洋碳埋藏。

{"title":"Responses of the dynamics of particulate organic matter to different track typhoons in coastal waters","authors":"Chunqing Chen , Qibin Lao , Xin Zhou , Shangjun Cai , Sihai Liu , Fajin Chen","doi":"10.1016/j.marchem.2025.104550","DOIUrl":"10.1016/j.marchem.2025.104550","url":null,"abstract":"<div><div>The impact of typhoons on marine biogeochemical processes depends on their intensity, track, and speed. However, how particulate organic matter (POM) dynamics respond to typhoons with distinct tracks remains poorly understood. This study investigated physicochemical parameters and stable isotopes of POM (δ<sup>13</sup>C-POC and δ<sup>15</sup>N-PN) through continuous observations (one cruise before the typhoon and four cruises after the typhoon, with a 5-day interval) in Zhanjiang Bay following two distinct track typhoons. During Typhoon Lionrock (landfall on the left side of the bay), onshore-wind stress drove high-salinity seawater intrusion, forming a strong salinity front in the bay that suppressed phytoplankton growth (Chl-<em>a</em> decreased by 80 %). In contrast, Typhoon Chaba (landfall on the right side of the bay) generated offshore-wind stress that resulted in weaker water mixing, while abundant terrestrial nutrient input promoted phytoplankton growth (Chl-<em>a</em> increased by two times in the 2nd and 4th cruises after the typhoon). Nevertheless, positive apparent oxygen utilization (AOU) values in the water column were observed after both typhoons, indicating strong decomposition of POM in Zhanjiang Bay. The strongest decomposition (over 80 %) for the two typhoons all occurred after 3 days of the typhoon landfall, and gradually decreased after 8 days of the typhoon landfall. The POM degraded after Typhoon Lionrock mainly originated from resuspended old POM, while from fresh POM (phytoplankton) after Typhoon Chaba. Additionally, the decomposition degree (56 %) induced by Lionrock was stronger than that induced by Chaba (44 %), suggesting that the typhoon landing on the left side of the bay are not conducive to marine carbon burial.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"272 ","pages":"Article 104550"},"PeriodicalIF":2.5,"publicationDate":"2025-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144842111","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}

引用次数: 0

Sedimentation and metal accumulation in the Gulf of Urabá – Colombian Caribbean: A 150-year record of natural processes and human impacts 乌拉巴湾-哥伦比亚加勒比海地区的沉积和金属积聚：150年的自然过程和人类影响记录

IF 2.5 3区地球科学 Q2 CHEMISTRY, MULTIDISCIPLINARY

Marine Chemistry

Pub Date : 2025-07-25 DOI: 10.1016/j.marchem.2025.104548

Pedro Pablo Vallejo-Toro , Javier Alcántara-Carrió , Diana María Agudelo-Echavarría , Jaime Palacio-Baena

Natural and human factors control the sediment accumulation rates and metal deposition in estuaries. This study analyzes the changes in sedimentation rates and metal accumulation in the Gulf of Urabá (southern Colombian Caribbean) over the last 150 years. The sedimentation rates of three cores (C1, C2, and C3) were determined using the constant flux (CF) model based on the ²¹⁰Pb isotope, averaging 0.14 cm/y, 0.22 cm/y and 0.10 cm/y, respectively. The temporal distribution of both major (Al, Fe, Ca, Mn) and minor (Zn, Cr, Cu, Ni) metals revealed important historical events, including the relocation of the main tributary mouth, intensive land use changes, and extreme climatic events. In agreement with previous studies in the area, moderate contamination and metal enrichment were found based on three geochemical indices (enrichment factor, anthropogenic factor and geo-accumulation index) considering global crust reference values. However, a lack of or minimal pollution was evident when considering the local background metal concentrations, which were determined in the bottom core sediments (2583 y BP). Therefore, this study evidences the relevance of using local background to determine metal pollution in surface sediments and cores. Despite high freshwater inputs and sediment supply, as well as anthropogenic activities in the gulf, sedimentation rates and metal accumulation are low compared to other marine environments worldwide, due to the presence of a salt wedge intrusion. The salt wedge creates a density difference, causing the clay fraction of the sediments, along with associated pollutants, to remain suspended for extended periods. As a result, sedimentation is hindered, and these materials are transported out of the gulf. Consequently, fine and medium silt dominate sedimentation and metal accumulation dynamics in the estuary.

自然和人为因素控制着河口泥沙堆积速率和金属沉积。本研究分析了过去150年来乌拉巴湾（哥伦比亚加勒比海南部）沉积速率和金属积累的变化。采用基于210Pb同位素的恒通量（CF）模型确定了C1、C2和C3 3个岩心的沉积速率，平均沉积速率分别为0.14 cm/y、0.22 cm/y和0.10 cm/y。主要金属（Al、Fe、Ca、Mn）和次要金属（Zn、Cr、Cu、Ni）的时间分布揭示了主要支流口迁移、土地集约利用变化和极端气候事件等重要历史事件。与前人研究结果一致，考虑全球地壳参考值，利用富集因子、人为因子和地成藏指数3个地球化学指标，发现该区存在中度污染和金属富集。然而，当考虑到在底部岩心沉积物（2583 y BP）中测定的当地背景金属浓度时，缺乏或最小的污染是明显的。因此，本研究证明了利用当地背景来确定地表沉积物和岩心中金属污染的相关性。尽管海湾有大量的淡水输入和沉积物供应，以及人为活动，但由于盐楔侵入的存在，与全球其他海洋环境相比，沉积速率和金属积累较低。盐楔产生了密度差，导致沉积物中的粘土部分以及相关污染物在较长时间内悬浮。结果，沉积受到阻碍，这些物质被运出海湾。因此，细粉砂和中粉砂在河口沉积和金属堆积动力学中占主导地位。

{"title":"Sedimentation and metal accumulation in the Gulf of Urabá – Colombian Caribbean: A 150-year record of natural processes and human impacts","authors":"Pedro Pablo Vallejo-Toro , Javier Alcántara-Carrió , Diana María Agudelo-Echavarría , Jaime Palacio-Baena","doi":"10.1016/j.marchem.2025.104548","DOIUrl":"10.1016/j.marchem.2025.104548","url":null,"abstract":"<div><div>Natural and human factors control the sediment accumulation rates and metal deposition in estuaries. This study analyzes the changes in sedimentation rates and metal accumulation in the Gulf of Urabá (southern Colombian Caribbean) over the last 150 years. The sedimentation rates of three cores (C1, C2, and C3) were determined using the constant flux (CF) model based on the <sup>210</sup>Pb isotope, averaging 0.14 cm/y, 0.22 cm/y and 0.10 cm/y, respectively. The temporal distribution of both major (Al, Fe, Ca, Mn) and minor (Zn, Cr, Cu, Ni) metals revealed important historical events, including the relocation of the main tributary mouth, intensive land use changes, and extreme climatic events. In agreement with previous studies in the area, moderate contamination and metal enrichment were found based on three geochemical indices (enrichment factor, anthropogenic factor and geo-accumulation index) considering global crust reference values. However, a lack of or minimal pollution was evident when considering the local background metal concentrations, which were determined in the bottom core sediments (2583 y BP). Therefore, this study evidences the relevance of using local background to determine metal pollution in surface sediments and cores. Despite high freshwater inputs and sediment supply, as well as anthropogenic activities in the gulf, sedimentation rates and metal accumulation are low compared to other marine environments worldwide, due to the presence of a salt wedge intrusion. The salt wedge creates a density difference, causing the clay fraction of the sediments, along with associated pollutants, to remain suspended for extended periods. As a result, sedimentation is hindered, and these materials are transported out of the gulf. Consequently, fine and medium silt dominate sedimentation and metal accumulation dynamics in the estuary.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"272 ","pages":"Article 104548"},"PeriodicalIF":2.5,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144749472","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}

引用次数: 0

Dynamics of ocean acidity, CO2 fluxes and metabolic rates on a shallow reef of Weizhou Island: a buoy-based observational study 涠洲岛浅海礁海洋酸度、CO2通量和代谢率的动态：浮标观测研究

IF 2.5 3区地球科学 Q2 CHEMISTRY, MULTIDISCIPLINARY

Marine Chemistry

Pub Date : 2025-07-25 DOI: 10.1016/j.marchem.2025.104549

Xu Dong , Baohong Chen , Jianjia Wang , Xinqing Zheng

The metabolic processes of calcification and production serve as crucial indicators of how environmental changes impact reef health. Previous studies suggest that Net Ecosystem Production (NEP) primarily drives Net Ecosystem Calcification (NEC) in the short-term. However, the functional relationship between these two carbon metabolisms remains poorly understood. We employed a mooring buoy approach to obtain simultaneous, high-frequency data of seawater pH, aragonite saturation state, CO₂ fluxes, and carbon metabolic rates over a coral reef on Weizhou Island for 37 consecutive days. Our findings revealed a strong linear correlation between NEC and NEP across both diel cycles and day-to-day timescales—this relationship held even when analyzing nighttime periods alone. This indicates an intrinsic link between carbon metabolisms that can operate independently of light. Furthermore, we observed predominantly negative daily NEC and NEP values, indicating persistent net CaCO₃ dissolution and net heterotrophy across the studied reef for over weeks. Our results suggest that CaCO₃ dissolution is more likely to occur in waters with heterotrophic conditions, implying that heterotrophy contributes to CaCO₃ dissolution. This tight coupling could be explained by reef sediment dissolution through the Carbonate Critical Threshold (CCT) mechanism. Our study highlights the significance of ambient respiration in driving reef ecosystem-scale CaCO₃ dissolution, especially in reefs with low live hard coral coverage. This process releases alkalinity into the seawater, helping to neutralize respiration-induced acidification. Additionally, we identified a higher rate of respiratory CO₂ release as the primary driver of CO₂ emissions from the studied reef.

钙化和生产的代谢过程是环境变化如何影响珊瑚礁健康的关键指标。以往的研究表明，短期内净生态系统生产（NEP）主要驱动净生态系统钙化（NEC）。然而，这两种碳代谢之间的功能关系仍然知之甚少。采用系泊浮标法，连续37天同步获取涠洲岛某珊瑚礁海域海水pH、文石饱和状态、CO2通量和碳代谢率的高频数据。我们的研究结果显示，NEC和NEP在昼夜周期和日常时间尺度上都有很强的线性相关性——即使只分析夜间时段，这种关系也成立。这表明碳代谢之间的内在联系可以独立于光而运作。此外，我们观察到主要为负的每日NEC和NEP值，表明在研究的珊瑚礁中持续的净CaCO3溶解和净异养超过数周。我们的研究结果表明，CaCO3溶解更可能发生在异养条件下的水域，这意味着异养有助于CaCO3溶解。这种紧密耦合可以用碳酸盐临界阈值（CCT）机制来解释。我们的研究强调了环境呼吸在驱动珊瑚礁生态系统尺度CaCO3溶解中的重要性，特别是在低活硬珊瑚覆盖的珊瑚礁中。这一过程将碱度释放到海水中，有助于中和呼吸引起的酸化。此外，我们确定了较高的呼吸二氧化碳释放率是所研究珊瑚礁二氧化碳排放的主要驱动因素。

{"title":"Dynamics of ocean acidity, CO2 fluxes and metabolic rates on a shallow reef of Weizhou Island: a buoy-based observational study","authors":"Xu Dong , Baohong Chen , Jianjia Wang , Xinqing Zheng","doi":"10.1016/j.marchem.2025.104549","DOIUrl":"10.1016/j.marchem.2025.104549","url":null,"abstract":"<div><div>The metabolic processes of calcification and production serve as crucial indicators of how environmental changes impact reef health. Previous studies suggest that Net Ecosystem Production (NEP) primarily drives Net Ecosystem Calcification (NEC) in the short-term. However, the functional relationship between these two carbon metabolisms remains poorly understood. We employed a mooring buoy approach to obtain simultaneous, high-frequency data of seawater pH, aragonite saturation state, CO<sub>2</sub> fluxes, and carbon metabolic rates over a coral reef on Weizhou Island for 37 consecutive days. Our findings revealed a strong linear correlation between NEC and NEP across both diel cycles and day-to-day timescales—this relationship held even when analyzing nighttime periods alone. This indicates an intrinsic link between carbon metabolisms that can operate independently of light. Furthermore, we observed predominantly negative daily NEC and NEP values, indicating persistent net CaCO<sub>3</sub> dissolution and net heterotrophy across the studied reef for over weeks. Our results suggest that CaCO<sub>3</sub> dissolution is more likely to occur in waters with heterotrophic conditions, implying that heterotrophy contributes to CaCO<sub>3</sub> dissolution. This tight coupling could be explained by reef sediment dissolution through the Carbonate Critical Threshold (CCT) mechanism. Our study highlights the significance of ambient respiration in driving reef ecosystem-scale CaCO<sub>3</sub> dissolution, especially in reefs with low live hard coral coverage. This process releases alkalinity into the seawater, helping to neutralize respiration-induced acidification. Additionally, we identified a higher rate of respiratory CO₂ release as the primary driver of CO<sub>2</sub> emissions from the studied reef.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"272 ","pages":"Article 104549"},"PeriodicalIF":2.5,"publicationDate":"2025-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144722316","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}

引用次数: 0

Unsaturated aliphatic and sulfur-containing organic matter as surfactants in the surface microlayer 不饱和脂肪族和含硫有机物作为表面活性剂在表面微层

IF 3 3区地球科学 Q2 CHEMISTRY, MULTIDISCIPLINARY

Marine Chemistry

Pub Date : 2025-07-20 DOI: 10.1016/j.marchem.2025.104547

N.R. Coffey , F.E. Agblemanyo , A.M. McKenna , A.S. Wozniak

The surface microlayer (SML) is a 10s–100s μm thick layer which mediates fluxes across the air-sea interface. Organic matter (OM) enrichments at the SML are known to influence SML physical properties and air-sea exchanges, but the role of detailed molecular level OM composition in influencing those processes hasn't been fully explored. SML and subsurface (SUB, 8–15 cm) water at four stations encompassing different influences (marine/fluvial/salt marsh) on the Delaware Bay system were sampled and examined for relationships between SML/SUB OM composition and surface tension. Samples collected December 2018–October 2019 show SML dissolved organic carbon (DOC) enrichments of 0.87 to 4.42 times the SUB concentration. Excitation-emission matrix spectroscopy (EEMs) and negative electrospray ionization (-ESI) Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) show marine samples have higher contributions from photobleached material and higher relative abundances of CHON compounds relative to inner bay sites, respectively. Principal component analyses further reveal consistent differences in SML OM composition relative to SUB. The SML contains higher abundances of compounds with H/C > 1.7 and O/C < 0.2, including sulfur-containing compounds - compositions suggestive of surfactant-like molecules, able to depress surface tension at the air-sea interface. Surface tension depressions were significantly correlated with unsaturated aliphatic and sulfur-containing compounds identified from FT-ICR MS data, yet showed no relationship with DOC abundances or enrichments, highlighting the need for compositional assessments for understanding OM influences on SML properties and air-sea exchanges. The sources and structures of SML surfactant molecules should be a focus of future work.

表面微层（SML）是一层10 ~ 100 μm厚的介质层，通过海气界面调节通量。已知SML的有机质（OM）富集会影响SML的物理性质和海气交换，但详细的分子水平OM组成在影响这些过程中的作用尚未得到充分探讨。对特拉华湾系统不同影响（海洋/河流/盐沼）的四个站点的SML和地下（SUB, 8-15 cm）水进行了采样，并检查了SML/SUB OM组成与表面张力之间的关系。2018年12月至2019年10月采集的样品显示，SML溶解有机碳（DOC）浓度为SUB浓度的0.87至4.42倍。激发-发射矩阵光谱（EEMs）和负电喷雾电离（-ESI）傅里叶变换离子回旋共振质谱（FT-ICR MS）显示，海洋样品中光漂白物质的贡献更高，CHON化合物的相对丰度相对于内湾站点更高。主成分分析进一步揭示了SML OM组成相对于SUB的一致差异。SML含有较高的H/C和gt化合物丰度；1.7和O/C <；0.2，包括含硫化合物——表面活性剂类分子的组成，能够降低海气界面的表面张力。表面张力下降与FT-ICR MS数据中鉴定的不饱和脂肪族和含硫化合物显著相关，但与DOC丰度或富集度没有关系，这表明需要进行成分评估，以了解OM对SML性质和海气交换的影响。SML表面活性剂分子的来源和结构是今后研究的重点。

{"title":"Unsaturated aliphatic and sulfur-containing organic matter as surfactants in the surface microlayer","authors":"N.R. Coffey , F.E. Agblemanyo , A.M. McKenna , A.S. Wozniak","doi":"10.1016/j.marchem.2025.104547","DOIUrl":"10.1016/j.marchem.2025.104547","url":null,"abstract":"<div><div>The surface microlayer (SML) is a 10s–100s μm thick layer which mediates fluxes across the air-sea interface. Organic matter (OM) enrichments at the SML are known to influence SML physical properties and air-sea exchanges, but the role of detailed molecular level OM composition in influencing those processes hasn't been fully explored. SML and subsurface (SUB, 8–15 cm) water at four stations encompassing different influences (marine/fluvial/salt marsh) on the Delaware Bay system were sampled and examined for relationships between SML/SUB OM composition and surface tension. Samples collected December 2018–October 2019 show SML dissolved organic carbon (DOC) enrichments of 0.87 to 4.42 times the SUB concentration. Excitation-emission matrix spectroscopy (EEMs) and negative electrospray ionization (-ESI) Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) show marine samples have higher contributions from photobleached material and higher relative abundances of CHON compounds relative to inner bay sites, respectively. Principal component analyses further reveal consistent differences in SML OM composition relative to SUB. The SML contains higher abundances of compounds with H/C > 1.7 and O/C < 0.2, including sulfur-containing compounds - compositions suggestive of surfactant-like molecules, able to depress surface tension at the air-sea interface. Surface tension depressions were significantly correlated with unsaturated aliphatic and sulfur-containing compounds identified from FT-ICR MS data, yet showed no relationship with DOC abundances or enrichments, highlighting the need for compositional assessments for understanding OM influences on SML properties and air-sea exchanges. The sources and structures of SML surfactant molecules should be a focus of future work.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"272 ","pages":"Article 104547"},"PeriodicalIF":3.0,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703845","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}

引用次数: 0

Investigation of open ocean ammonium aerosol sources in the North Pacific Ocean (Oahu, Hawaii) 北太平洋（夏威夷瓦胡岛）开阔海域铵态气溶胶源调查

IF 2.5 3区地球科学 Q2 CHEMISTRY, MULTIDISCIPLINARY

Marine Chemistry

Pub Date : 2025-07-20 DOI: 10.1016/j.marchem.2025.104545

Alexandra B. MacFarland , Wendell W. Walters , Katye E. Altieri , Meredith G. Hastings

Anthropogenic nitrogen (N) deposition entering the ocean from the atmosphere has increased over time. Ammonia (NH₃), a precursor to ammonium (NH₄⁺), is released into the atmosphere via both natural sources (e.g., ammonification, biomass burning, waste products, surface ocean emissions) and anthropogenic sources (e.g., agriculture, industry, sewage, vehicle emissions). Studies disagree on the quantity of anthropogenic N deposition to the ocean, as well as the consequences this excess N poses to the biogeochemistry of the open ocean, particularly in the Pacific Ocean. Understanding the current role that the open ocean is playing in the N cycle and budget is essential to determine the sources of N (e.g., internal or external, recycled or excess) and to further distinguish the relationships between atmospheric and oceanic N. Therefore, in the current study, ion concentrations and ammonium isotope values (δ¹⁵N-NH₄⁺) were measured for aerosol samples collected on the coast of Oahu, Hawaii from 2021 to 2022 (n = 67). This location was chosen based on low anthropogenic activity, access to the open ocean, and the premise of a dominant marine signal. Particulate NH₄⁺ concentrations ([NH₄⁺]) averaged 3.7 ± 7.3 ng/m³, with no distinct seasonality (p > 0.05). The δ¹⁵N-NH₄⁺ values also did not exhibit distinct seasonality (p > 0.05), but did fall into three unique clusters (using a K-means clustering analysis): cluster one = 19.0 ± 3.9 ‰ (n = 8), cluster two = 4.1 ± 2.3 ‰ (n = 31), and cluster three = −3.3 ± 2.4 ‰ (n = 13). Cluster three was best explained as an ocean emissions signature, which was determined via a phase partitioning model that incorporated N isotope fractionation associated with NH₃ conversion to NH₄⁺. Cluster one had higher than average [NH₄⁺] along with air mass origins from two seabird sanctuaries and was hypothesized to be a seabird emission signature. Cluster two was considered a mix of these two sources (67 % marine, 33 % seabird emissions). 6 % of aerosol inorganic N (NH₄⁺ + nitrate; annual dry inorganic N = 5.5 ng/m³) is from [NH₄⁺], with 35 % resulting from seabird emissions. The annual inorganic N (IN; NO₃⁻ + NH₄⁺) dry deposition value for this site was 1.2 ± 1.1 Tg N·y⁻¹.

随着时间的推移，从大气进入海洋的人为氮(N)沉积有所增加。氨（NH3）是铵（NH4+）的前体，通过自然来源（如氨化作用、生物质燃烧、废物、海洋表面排放）和人为来源（如农业、工业、污水、车辆排放）释放到大气中。关于人为氮沉积到海洋的数量，以及这种过量的氮对开放海洋，特别是太平洋的生物地球化学造成的后果，研究意见不一。了解开放海洋目前在N循环和收支中所起的作用，对于确定N的来源（例如，内部或外部，再循环或过剩）以及进一步区分大气和海洋N之间的关系至关重要。因此，在目前的研究中，对2021年至2022年在夏威夷瓦胡岛海岸收集的气溶胶样本（N = 67）进行了离子浓度和铵同位素值（δ15N-NH4+）的测量。这个地点的选择是基于低人为活动，进入开阔的海洋，以及海洋信号占主导地位的前提。颗粒NH4+浓度（[NH4+]）平均为3.7±7.3 ng/m3，无明显的季节性(p >；0.05)。δ15N-NH4+值也没有明显的季节性(p >；0.05)，但确实属于三个独特的聚类（使用K-means聚类分析）：聚类1 = 19.0±3.9‰（n = 8），聚类2 = 4.1±2.3‰（n = 31），聚类3 =−3.3±2.4‰（n = 13）。聚类3最好解释为海洋排放特征，这是通过相分配模型确定的，该模型包含了与NH3转化为NH4+相关的N同位素分馏。集群1的[NH4+]含量高于平均水平，并且来自两个海鸟保护区的气团也高于平均水平，并被假设为海鸟排放的特征。第二组被认为是这两种来源的混合（67%来自海洋，33%来自海鸟）。6%的气溶胶无机N （NH4+ +）硝酸盐；年干无机N = 5.5 ng/m3)来自[NH4+]， 35%来自海鸟排放。年无机氮(IN；NO3−+ NH4+)干沉积值为1.2±1.1 Tg N·y−1。

{"title":"Investigation of open ocean ammonium aerosol sources in the North Pacific Ocean (Oahu, Hawaii)","authors":"Alexandra B. MacFarland , Wendell W. Walters , Katye E. Altieri , Meredith G. Hastings","doi":"10.1016/j.marchem.2025.104545","DOIUrl":"10.1016/j.marchem.2025.104545","url":null,"abstract":"<div><div>Anthropogenic nitrogen (N) deposition entering the ocean from the atmosphere has increased over time. Ammonia (NH<sub>3</sub>), a precursor to ammonium (NH<sub>4</sub><sup>+</sup>), is released into the atmosphere via both natural sources (e.g., ammonification, biomass burning, waste products, surface ocean emissions) and anthropogenic sources (e.g., agriculture, industry, sewage, vehicle emissions). Studies disagree on the quantity of anthropogenic N deposition to the ocean, as well as the consequences this excess N poses to the biogeochemistry of the open ocean, particularly in the Pacific Ocean. Understanding the current role that the open ocean is playing in the N cycle and budget is essential to determine the sources of N (e.g., internal or external, recycled or excess) and to further distinguish the relationships between atmospheric and oceanic N. Therefore, in the current study, ion concentrations and ammonium isotope values (δ<sup>15</sup>N-NH<sub>4</sub><sup>+</sup>) were measured for aerosol samples collected on the coast of Oahu, Hawaii from 2021 to 2022 (<em>n</em> = 67). This location was chosen based on low anthropogenic activity, access to the open ocean, and the premise of a dominant marine signal. Particulate NH<sub>4</sub><sup>+</sup> concentrations ([NH<sub>4</sub><sup>+</sup>]) averaged 3.7 ± 7.3 ng/m<sup>3</sup>, with no distinct seasonality (<em>p</em> > 0.05). The δ<sup>15</sup>N-NH<sub>4</sub><sup>+</sup> values also did not exhibit distinct seasonality (<em>p</em> > 0.05), but did fall into three unique clusters (using a K-means clustering analysis): cluster one = 19.0 ± 3.9 ‰ (<em>n</em> = 8), cluster two = 4.1 ± 2.3 ‰ (<em>n</em> = 31), and cluster three = −3.3 ± 2.4 ‰ (<em>n</em> = 13). Cluster three was best explained as an ocean emissions signature, which was determined via a phase partitioning model that incorporated N isotope fractionation associated with NH<sub>3</sub> conversion to NH<sub>4</sub><sup>+</sup>. Cluster one had higher than average [NH<sub>4</sub><sup>+</sup>] along with air mass origins from two seabird sanctuaries and was hypothesized to be a seabird emission signature. Cluster two was considered a mix of these two sources (67 % marine, 33 % seabird emissions). 6 % of aerosol inorganic N (NH<sub>4</sub><sup>+</sup> + nitrate; annual dry inorganic <em>N</em> = 5.5 ng/m<sup>3</sup>) is from [NH<sub>4</sub><sup>+</sup>], with 35 % resulting from seabird emissions. The annual inorganic N (IN; NO<sub>3</sub><sup>−</sup> + NH<sub>4</sub><sup>+</sup>) dry deposition value for this site was 1.2 ± 1.1 Tg N·y<sup>−1</sup>.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"272 ","pages":"Article 104545"},"PeriodicalIF":2.5,"publicationDate":"2025-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144767061","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}

引用次数: 0

Comparative assessment of preservation methods for major nutrients in polar seawater 极地海水中主要营养物质保存方法的比较评价

IF 3 3区地球科学 Q2 CHEMISTRY, MULTIDISCIPLINARY

Marine Chemistry

Pub Date : 2025-07-17 DOI: 10.1016/j.marchem.2025.104546

Mi Seon Kim , Man Sik Choi , Tae Siek Rhee

Major nutrients—nitrate, phosphate, and silicate—are fundamental building blocks of marine biomass. To understand the flow of material and energy in the ecosystem, it is essential to accurately quantify nutrients concentrations. When shipboard analysis is not possible, seawater samples must be preserved without altering their contents. In this study, we investigated a range of commonly used preservation methods, including filtration, chemical poisoning with HgCl₂, and freezing at −20 °C or − 80 °C without pre-treatment, all aimed at minimizing biological activities. We also evaluated the effects of sample storage periods and thawing periods required before analysis in freezing treatments to determine their impact on nutrients contents. Using four different statistical methods, we assessed a total of 19 experiments to identify the most effective preservation method. Comparison between filtered and untreated seawater samples showed no detectable effect on the preservation by filtration. Deviations from shipboard measurement were detected in samples stored in a freezer, even at −80 °C. On the other hand, the nutrient content in the poisoned samples remained virtually intact. The deficiency in nutrient content observed during prolonged freezing and thawing or storage in a refrigerator at 4 °C, compared to shipboard measurements, aligns with the Redfield relationship reported in the Arctic Ocean, suggesting that biological activities occurred either within brine channels during freezing, during refrigerated storage, or both, likely due to viable cold-adapted microbes. Although our findings are based on polar seawater samples, potential biological activities during storage and post-treatment should be carefully examined in the other oceanic regions.

主要营养物质——硝酸盐、磷酸盐和硅酸盐——是海洋生物量的基本组成部分。为了了解生态系统中物质和能量的流动，准确量化营养物质的浓度是至关重要的。当无法在船上进行分析时，必须在不改变其内容的情况下保存海水样品。在这项研究中，我们研究了一系列常用的保存方法，包括过滤、用HgCl2化学中毒、在- 20°C或- 80°C冷冻而不进行预处理，所有这些方法都旨在最大限度地减少生物活性。我们还评估了样品在冷冻处理分析前所需的储存期和解冻期的影响，以确定它们对营养成分的影响。采用4种不同的统计方法对19个实验进行评估，以确定最有效的保存方法。过滤后和未经处理的海水样品的比较表明，过滤对保存没有明显的影响。即使在- 80°C的温度下，也可以在冷冻库中检测到与船上测量值的偏差。另一方面，中毒样本中的营养成分几乎完好无损。与船上的测量结果相比，在长时间的冷冻和解冻或在4°C的冰箱中储存期间观察到的营养含量不足，与在北冰洋报道的雷德菲尔德关系一致，表明生物活动在冷冻期间或冷藏期间发生在盐水通道内，或两者同时发生，可能是由于活的冷适应微生物。虽然我们的发现是基于极地海水样本，但在其他海洋区域，应仔细检查储存和后处理过程中潜在的生物活性。

{"title":"Comparative assessment of preservation methods for major nutrients in polar seawater","authors":"Mi Seon Kim , Man Sik Choi , Tae Siek Rhee","doi":"10.1016/j.marchem.2025.104546","DOIUrl":"10.1016/j.marchem.2025.104546","url":null,"abstract":"<div><div>Major nutrients—nitrate, phosphate, and silicate—are fundamental building blocks of marine biomass. To understand the flow of material and energy in the ecosystem, it is essential to accurately quantify nutrients concentrations. When shipboard analysis is not possible, seawater samples must be preserved without altering their contents. In this study, we investigated a range of commonly used preservation methods, including filtration, chemical poisoning with HgCl<sub>2</sub>, and freezing at −20 °C or − 80 °C without pre-treatment, all aimed at minimizing biological activities. We also evaluated the effects of sample storage periods and thawing periods required before analysis in freezing treatments to determine their impact on nutrients contents. Using four different statistical methods, we assessed a total of 19 experiments to identify the most effective preservation method. Comparison between filtered and untreated seawater samples showed no detectable effect on the preservation by filtration. Deviations from shipboard measurement were detected in samples stored in a freezer, even at −80 °C. On the other hand, the nutrient content in the poisoned samples remained virtually intact. The deficiency in nutrient content observed during prolonged freezing and thawing or storage in a refrigerator at 4 °C, compared to shipboard measurements, aligns with the Redfield relationship reported in the Arctic Ocean, suggesting that biological activities occurred either within brine channels during freezing, during refrigerated storage, or both, likely due to viable cold-adapted microbes. Although our findings are based on polar seawater samples, potential biological activities during storage and post-treatment should be carefully examined in the other oceanic regions.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"272 ","pages":"Article 104546"},"PeriodicalIF":3.0,"publicationDate":"2025-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144703844","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}

引用次数: 0

Corrigendum to “Boron to salinity ratios in the Fram Strait entering the Central Arctic: The role of sea ice formation and future predictions” [Marine Chemistry 267 (2024) 104463] “进入北极中部的弗拉姆海峡的硼盐比：海冰形成的作用和未来预测”[海洋化学267(2024)104463]的勘误表。

IF 3 3区地球科学 Q2 CHEMISTRY, MULTIDISCIPLINARY

Marine Chemistry

Pub Date : 2025-07-11 DOI: 10.1016/j.marchem.2025.104534

Samantha Rush , Penny Vlahos , Chang-Ho Lee , Kitack Lee , Lauren J. Barrett

引用次数: 0