Marine Chemistry最新文献

{"title":"Responses of the dynamics of particulate organic matter to different track typhoons in coastal waters","authors":"Chunqing Chen ,&nbsp;Qibin Lao ,&nbsp;Xin Zhou ,&nbsp;Shangjun Cai ,&nbsp;Sihai Liu ,&nbsp;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 (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-<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":"2025-09-01","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}

{"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 ,&nbsp;Baohong Chen ,&nbsp;Jianjia Wang ,&nbsp;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, 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.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"272 ","pages":"Article 104549"},"PeriodicalIF":2.5,"publicationDate":"2025-09-01","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}

{"title":"Copper-binding organic ligands and phytoplankton growth in Japanese coastal waters","authors":"Wiwit ,&nbsp;Kuo Hong Wong ,&nbsp;Chia-Jung Lu ,&nbsp;Hideki Fukuda ,&nbsp;Hiroshi Ogawa ,&nbsp;Shigenobu Takeda ,&nbsp;Kazutaka Takahashi ,&nbsp;Asami S. Mashio ,&nbsp;Hajime Obata","doi":"10.1016/j.marchem.2025.104532","DOIUrl":"10.1016/j.marchem.2025.104532","url":null,"abstract":"<div><div>Although copper (Cu) is necessary for phytoplankton growth, it becomes toxic at high concentrations. The bioavailability and toxicity of Cu are governed by its chemical speciation, with free inorganic Cu²⁺ being the most toxic species. In this study, we estimated free Cu²⁺ concentrations in Japanese coastal waters to evaluate the effects of Cu toxicity on phytoplankton growth. Incubation experiments were conducted using natural phytoplankton assemblages in seawater collected from Otsuchi Bay, northeastern Japan, and Goto-nada in the East China Sea. The cells were incubated for 14 days with Cu additions of up to 100 nM. Copper speciation parameters were determined using the reverse titration methods with competitive ligand exchange adsorptive cathodic stripping voltammetry (CLE-AdCSV). Chlorophyll-<em>a</em> concentrations increased with the addition of &lt;10 nM Cu but decreased at 100 nM Cu due to Cu toxicity. We found that phytoplankton growth caused negligible increases in Cu-binding organic ligand concentrations. Free Cu²⁺ concentrations were simulated using the initial Cu speciation parameters obtained from the reverse titration method under varying Cu concentrations. When assuming the presence of only one class of organic ligands, the estimated Cu²⁺ concentrations were inconsistent with the incubation results. In contrast, by considering two classes of ligands, the increase in the concentration of Cu²⁺ closely matched the incubation data. This suggests that the resolution of the weaker class of organic ligands is crucial for evaluating Cu toxicity in seawater.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"271 ","pages":"Article 104532"},"PeriodicalIF":3.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144501772","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":"Spatial variability of marine carbonate system along the Drake Passage and northern Antarctic Peninsula during the austral summer","authors":"Thiago Monteiro ,&nbsp;Matheus Batista ,&nbsp;Rodrigo Kerr","doi":"10.1016/j.marchem.2025.104529","DOIUrl":"10.1016/j.marchem.2025.104529","url":null,"abstract":"<div><div>The influence of physical and biogeochemical processes on the variability of the carbonate system in the Southern Ocean remains poorly constrained. Understanding this influence is crucial to distinguish natural variations from anthropogenic impacts and accurately interpret observed trends. Here, we investigate how physical and biogeochemical processes influence the spatial distribution of summer carbonate system variables along the Drake Passage and northern Antarctic Peninsula. Continuous, high-frequency surface partial pressure of CO₂ (<em>p</em>CO₂), dissolved oxygen (O₂) and essential hydrographic variables were collected during the austral summer of 2019, whereas other carbonate system variables were estimated after the reconstruction and evaluation of total alkalinity. Our findings show that in the Drake Passage, Circumpolar Deep Water upwelling increases the <em>p</em>CO₂ (&gt; 400 μatm) and dissolved inorganic carbon (&gt; 2175 μmol kg⁻¹), leading to reduced pH (&lt; 7.99) south of the Polar Front. North of the Polar Front, photosynthesis lowers <em>p</em>CO₂ (&lt; 390 μatm), while increasing pH (&gt; 8.00) and carbonate ions (&gt; 110 μmol kg⁻¹), with enrichment occurring in the Subantarctic coccolithophore growth region. Along the northern Antarctic Peninsula, including Gerlache Strait, Antarctic Sound, and Admiralty Bay, photosynthesis and sea ice/glacial melt are the main drivers of <em>p</em>CO₂ reductions to levels below 350 μatm. The mixing of Circumpolar Deep Water with Weddell Sea Dense Shelf Water can naturally and anthropogenically raise <em>p</em>CO₂ and decrease pH in northern Antarctic Peninsula waters, where pH is generally lower (as low as 7.90) compared to adjacent areas. Nevertheless, most environments remain supersaturated with respect to carbonate minerals calcite and aragonite, although signs of aragonite undersaturation have occur in surface waters influenced by Dense Shelf Water. These findings offer new insights into carbonate system processes across a large Southern Ocean region, improving understanding of spatial variability in marine carbon dynamics.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"271 ","pages":"Article 104529"},"PeriodicalIF":3.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144205285","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 cross-shelf transport and accumulation of particulate organic carbon in the continental margin bottom sediments using Aluminum and 210Pb","authors":"Hojong Seo ,&nbsp;Guebuem Kim","doi":"10.1016/j.marchem.2025.104530","DOIUrl":"10.1016/j.marchem.2025.104530","url":null,"abstract":"<div><div>We investigated particulate organic carbon (POC) transport across the shelf to the basin bottom in the East/Japan Sea, using Aluminum (Al) and ²¹⁰Pb as tracers. Our results show that the sedimentary deposition of ²¹⁰Pb in the basin (2327 m) is comparable with the scavenging removal flux from the water column (117 ± 15 %), whereas it increases threefold in the shelf (296 ± 50 %) (200 m), suggesting substantial lateral inputs of land- and shelf-origin sediments. We also show that conventionally used excess ²¹⁰Pb-derived sedimentation rates without considering mixing can be overestimated by 3–8 times in continental margin sediments, where sedimentation rates are low (&lt; 0.15 cm yr⁻¹), leading to significant overestimation of POC burial fluxes. Sedimentation rates based on an Al mass balance with sedimentary ²¹⁰Pb budgets align more closely with those from ¹⁴C and tephra analyses in this region. A POC box model using the refined sedimentation rate indicates that POC burial fluxes in the East Sea are 0.3–1.0 % of primary production. These values are four times lower than previous estimates based on ²¹⁰Pb-derived sedimentation rates in the same region, but consistent with those observed in similar oceanic settings. Additionally, the POC box model suggests that sediment resuspensions can significantly contribute (34–70 %) to sinking POC fluxes in the bottom sediments. Thus, our results highlight that in continental margins, where ²¹⁰Pb decay and mixing are difficult to distinguish due to slow sedimentation rates, traditional ²¹⁰Pb dating methods can significantly overestimate sedimentation rates and associated material fluxes.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"271 ","pages":"Article 104530"},"PeriodicalIF":3.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144230867","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":"In situ measurement of trace sulfide concentrations in marine coastal waters using diffusive gradient in thin film passive samplers","authors":"Kevin Diaz ,&nbsp;David Point ,&nbsp;Wilson Carhuapoma ,&nbsp;Astrid Avellan ,&nbsp;Maricarmen Igarza ,&nbsp;Jesús Ledesma ,&nbsp;Fanny Rioual ,&nbsp;Michelle Graco","doi":"10.1016/j.marchem.2025.104521","DOIUrl":"10.1016/j.marchem.2025.104521","url":null,"abstract":"<div><div>The diffusive gradient in thin film technique (DGT) represents an <em>in situ</em> passive sampling method designed to preconcentrate various compounds, including sulfides, for detection at low concentrations. While DGT applications for sulfides have been studied in freshwater, this research extends its use to marine environments. A detailed methodology is presented for synthesizing, assembling, calibrating, and field-deploying DGT samplers to measure sulfides in the low micromolar range in marine waters. The in-house DGT samplers developed in this study demonstrated improved performance, with more homogeneous binding gels and smaller silver iodide particles (0.51 ± 0.34 μm) compared to commercial alternatives. Grayscale imaging enabled accurate quantification of sulfide accumulation in the gels, confirming the method's reliability for detecting trace-level sulfides in marine environments. Comparative analysis showed in-house and commercial samplers performed similarly in estimating sulfide concentrations. Field deployments along the Peruvian coast revealed significant vertical and spatial sulfide gradients. In the Callao coastal area (12°S) (July–August 2022), concentrations ranged from 0.03 to 0.45 μM across a 35 m depth profile. In Paracas bay (13.8°S) (March–April 2023), a shallower coastal station, concentrations ranged from 1.17 to 6.46 μM, reflecting increased benthic production. These results highlight the utility of DGT samplers as cost-effective tools for biogeochemical monitoring, enabling studies of the ocean sulfur cycle. The findings emphasize the growing application of DGTs in marine and coastal water column research.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"271 ","pages":"Article 104521"},"PeriodicalIF":3.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143917536","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":"Dust deposition directly affects the concentration of dissolved organic carbon in the ocean","authors":"Rianne J.M. van Kaam,&nbsp;Martin Kölling,&nbsp;Marcus Elvert,&nbsp;Kai-Uwe Hinrichs,&nbsp;Matthias Zabel","doi":"10.1016/j.marchem.2025.104531","DOIUrl":"10.1016/j.marchem.2025.104531","url":null,"abstract":"<div><div>Dust deposition to the ocean plays an indirect role in the carbon cycle due to stimulating the primary production by fertilisation. Additionally, it transports carbon to the ocean floor by acting as ballast for marine aggregates. Despite these recognized impacts, the direct influence of dust-seawater interactions on the carbon cycle remains poorly understood. Here, we study the effects of mineral dust on the dissolved organic carbon (DOC) concentration in seawater by performing sorption experiments through time series and stable carbon isotope analysis. We added two different amounts of dust to a solution of artificial seawater and ¹³C-labelled dissolved organic matter from <em>Spirulina</em> extract, creating a low and high dust-seawater ratio system. After 72 h, we observe a decrease in DOC for both systems, indicating the adsorption of DOC from the <em>Spirulina</em> extract onto dust particles. Analysis of the stable carbon isotope ratios of total organic carbon on the dust samples, before and after the sorption experiments, confirms these findings. Furthermore, our study shows that the net uptake of DOC on dust depends on the relative importance of adsorption, release and degradation of organic carbon. DOC release can become the dominant process based on the dust-seawater ratio and the initial organic carbon present on the dust, demonstrating that dust can act as both a sink and a source of organic carbon in the near-surface waters.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"271 ","pages":"Article 104531"},"PeriodicalIF":3.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144557449","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":"Diatom-induced calcification in coastal marine environments: Biomineralization threshold and mechanism","authors":"Qixian Chen ,&nbsp;Yifan Li ,&nbsp;Chen-Tung Arthur Chen ,&nbsp;Zong-Pei Jiang ,&nbsp;Wei-Jun Cai ,&nbsp;Hongwen Pan ,&nbsp;Yunwen Shen ,&nbsp;Zesheng Ding ,&nbsp;Yanan Di ,&nbsp;Chenba Zhu ,&nbsp;Nianzhi Jiao ,&nbsp;Yiwen Pan","doi":"10.1016/j.marchem.2025.104533","DOIUrl":"10.1016/j.marchem.2025.104533","url":null,"abstract":"<div><div>Diatoms play a pivotal role in the ocean, contributing approximately 40 % of marine primary production, with nearly half of the particulate organic carbon being exported. The recent discovery of a novel diatom-induced calcification pathway has attracted significant attention due to its implications for marine carbon, calcium, and silicon cycling. Despite its potential, the lack of a quantitative initiation threshold and comparative analysis with known calcifying organisms limit our ability to predict its ecological impact, particularly on carbon sequestration. This study addresses these gaps by cultivating the common diatom species, <em>Skeletonema costatum</em>, under simulated marine conditions to evaluate its CaCO₃ precipitation potential and define the biogeochemical threshold for calcification. The experimental results showed that <em>S. costatum</em> can induce calcification across a range of environmental conditions, including varying dissolved inorganic carbon (DIC 1837 to 2709 μmol·kg⁻¹), nitrogen sources (NH₄⁺ or NO₃⁻), and cell densities (10⁴ to 10⁵ cells·mL⁻¹). Calcification was initiated when the aragonite saturation state (Ω_arag) exceeded ∼8. The calcification rate exhibits a linear correlation with Ω_arag in the bulk solution, categorizing it as a “biologically induced” process. Our findings highlight similarities between the calcification mechanisms of <em>S. costatum</em> and other calcifying organisms, revealing the common ality of environmental drivers. This study advances our understanding of diatom-induced calcification, offering insights into its role in the marine carbon cycle and potential contributions to carbon sequestration strategies.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"271 ","pages":"Article 104533"},"PeriodicalIF":3.0,"publicationDate":"2025-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144524021","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":"Surface macro- and micro-nutrients within the Copper River plume region respond to along-shore winds","authors":"E.L.S. Ortega,&nbsp;I. Reister,&nbsp;S.L. Danielson,&nbsp;A.M. Aguilar-Islas","doi":"10.1016/j.marchem.2025.104508","DOIUrl":"10.1016/j.marchem.2025.104508","url":null,"abstract":"<div><div>The Copper River is a major source of freshwater to the Northern Gulf of Alaska (NGA) shelf with a seasonal cycle that reaches peak discharge in summer. This glacially-fed river also provides a large input of dissolved chemicals to the NGA, and because of its large particle load, it impacts the distribution of particle-reactive elements. Summertime sampling of shelf water properties was carried out within the Copper River plume region during two years: first during a period of upwelling-favorable winds and higher river discharge (4–7 July 2019) and later during lower river discharge and more typical downwelling conditions (11–13 July 2020). Although these wind conditions were observed in separate years, both can occur over the course of a single summer. We found that the export of most nutrients to surface shelf waters was enhanced under upwelling-favorable winds accompanied by higher river discharge compared to downwelling conditions and lower discharge. For example, greater cross-shelf plume transport in 2019 resulted in higher mid-shelf surface inventories for nitrate + nitrite (N + N), silicic acid (H₄SiO₄), phosphate (PO₄³⁻), dissolved Fe (dFe), and dissolved Cu (dCu) compared to 2020. Entrainment of relatively macronutrient-rich subsurface waters under upwelling conditions may also have contributed to the enhancement of these mid-shelf nutrient inventories. The observed high N:P ratios in plume waters were likely driven by the scavenging of P within particle-laden plume waters. Similarly, we observed lower than expected [dFe] (1.58 to 6.12 nM) in particle-laden plume waters, likely a result of enhanced scavenging combined with low concentrations of dissolved Fe-binding ligands. Although dNi and dZn have a river source, we observed lower concentrations in surface shelf waters under upwelling conditions, suggesting enhanced dilution by relatively micronutrient-poor subsurface waters. Results highlight the influence of sub-seasonal variations in atmospheric forcing on nutrient distributions and suggest that this forcing also impacts the location and timing of primary production hotspots during summer, adding to the ecological mosaic of the NGA across a range of temporal and spatial scales.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"270 ","pages":"Article 104508"},"PeriodicalIF":3.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143510835","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":"Comparative analysis of HPLC methods for measuring phytoplankton pigments in the Western Mediterranean Sea: A contribution to the satellite Cal/Val activities","authors":"Elisabetta Canuti ,&nbsp;F. Artuso ,&nbsp;A. Di Cicco","doi":"10.1016/j.marchem.2025.104516","DOIUrl":"10.1016/j.marchem.2025.104516","url":null,"abstract":"<div><div>High-performance liquid chromatography (HPLC) is the gold standard for calibrating and validating satellite-derived Chlorophyll <em>a</em> (TChl <em>a</em>) concentration. Other phytoplankton pigments quantified by HPLC can provide taxonomic and functional insights into the composition and abundance of phytoplankton communities. This study assesses the uncertainties associated with HPLC measurements by comparing results from two analytical laboratories, one from the Joint Research Centre (JRC) and the other from the Italian National Agency for New Technologies, Energy, and Sustainable Economic Development (ENEA). These laboratories employed different analytical methods to examine natural water samples from the oligotrophic waters of the Western Mediterranean Sea, collected during the Sentinel 2017 campaign. Chlorophyll <em>a</em> concentrations in these samples ranged from 0.048 to 0.653 mg m⁻³ in the JRC dataset. The present study evaluated phytoplankton community composition using multiple techniques, including chemotaxonomic methods based on the analysis of biomarker pigments and CHEMTAX method (<span><span>Mackey et al., 1996</span></span>), alongside unsupervised machine learning approaches such as Hierarchical Clustering Analysis (HCA), Principal Components Analysis (PCA), and Network-Community Analysis (NCA). Significant differences in pigment quantification were observed between the two laboratories, particularly for chlorophylls <em>c</em> (85.5 % difference) and peridinin (56.6 % difference). However, differences in total TChl <em>a</em> quantification were within 6.1 %, indicating that both laboratories are capable of supporting satellite data validation and algorithm development (Hooker et al., 2000). The results highlighted both limitations and advantages of this comparative approach, related to different methods for estimating uncertainties, providing insights into the consistency and reliability of HPLC measurements in a challenging low concentration matrix.</div></div>","PeriodicalId":18219,"journal":{"name":"Marine Chemistry","volume":"270 ","pages":"Article 104516"},"PeriodicalIF":3.0,"publicationDate":"2025-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143851334","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}