Limnology and Oceanography: Methods最新文献

An aquatic mesocosm array to regulate spatial and temporal water temperature variability 调节水温时空变化的水生中生态阵列

IF 2.1 3区地球科学

Limnology and Oceanography: Methods Pub Date : 2025-06-09 DOI: 10.1002/lom3.10698

Daniel Gibson, Jay Ewing, Samuel B. Fey

{"title":"An aquatic mesocosm array to regulate spatial and temporal water temperature variability","authors":"Daniel Gibson, Jay Ewing, Samuel B. Fey","doi":"10.1002/lom3.10698","DOIUrl":"https://doi.org/10.1002/lom3.10698","url":null,"abstract":"Temporal and spatial variability in temperature are key habitat features that will determine individual, population, and community-level responses to global climate warming. Lakes and ponds exhibit thermal heterogeneity in the form of diel and seasonal fluctuations as well as vertical stratification; however, experimental studies of warming in these ecosystems have largely focused on elevated mean temperatures within thermally homogeneous settings. Thus, new tools are needed to incorporate temperature variability into aquatic mesocosm experiments. We present a design for a mesocosm array to simulate lentic environments with different magnitudes of spatial and temporal temperature variability. Each mesocosm consists of a 77-L plastic container heated by two independent band heaters, where water temperature is regulated via a programmable logic controller that receives feedback from thermocouples. We find that the controller is capable of producing high temperatures (> 35°C) and substantial thermal stratification, with low variability between replicate mesocosms. We generated a vertical temperature gradient up to 12.4°C across 54 cm of water depth and diel fluctuations up to 12.2°C in the surface layer (top 14 cm). We additionally demonstrate the utility of the mesocosm array for other common applications, including temperature ramps and real-time transformations of ambient temperature time series. The control system's ability to simultaneously regulate temporal and spatial thermal variability, while being cost-effective and requiring relatively little technical knowledge to assemble, demonstrates the utility of the array for ecological experiments that seek to investigate the impacts of climate warming on thermally variable aquatic ecosystems.","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 7","pages":"467-481"},"PeriodicalIF":2.1,"publicationDate":"2025-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lom3.10698","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635218","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}

引用次数: 0

Refining resolution settings for analysis of dissolved organic matter in varied natural environments by Fourier-transform ion cyclotron resonance mass spectrometry 改进傅里叶变换离子回旋共振质谱法分析不同自然环境中溶解有机物的分辨率设置

IF 2.1 3区地球科学

Limnology and Oceanography: Methods Pub Date : 2025-06-06 DOI: 10.1002/lom3.10696

Shuchai Gan, Shiting Huang, Pengran Guo, Ying Wu, Faming Wang, Bin Jiang, Yumei Song, Jiachuan Pan, Zheng Gong

{"title":"Refining resolution settings for analysis of dissolved organic matter in varied natural environments by Fourier-transform ion cyclotron resonance mass spectrometry","authors":"Shuchai Gan, Shiting Huang, Pengran Guo, Ying Wu, Faming Wang, Bin Jiang, Yumei Song, Jiachuan Pan, Zheng Gong","doi":"10.1002/lom3.10696","DOIUrl":"https://doi.org/10.1002/lom3.10696","url":null,"abstract":"Dissolved organic matter (DOM) is a major carbon reservoir and exhibits high chemo-diversity and similarity. Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) enables analysis of DOM due to its ultrahigh resolution at various field strengths. Capturing distinguishing features of DOM is especially challenging for lower resolution instruments. Here, we aim to refine resolution settings for various types of DOM. With a low-field 7 Tesla (T) FT-ICR MS, two strategies for tuning resolution were compared with free induction decay (FID) of 1–4 s: the initial mass to charge (m/z) ratio (A) and data size (B). Peak number rises then falls with data size; 16 M leads to loss of low-mass compounds (< 220 m/z). In further, the comparability of intensity-weighted average parameters was evaluated, revealing that m/z, carbon number, H/C, O/C, aromatic index, and double bond equivalent have a coefficient of variation (CV) of < 3%; in contrast, the average number of heteroatoms—P (45%), N (21%), and S (22%)—shows considerable CV (%) with resolution, varying across samples. Furthermore, the minimum required value of resolution varies across samples, ranging from > 300,000 to > 500,000: it increases from riverine water to porewater, and then to seawater DOM, typically exhibiting abundant CHO, CHOS, and CHOP, respectively. For a 7T FT-ICR MS, we propose tailored FID strategies: a 2-s medium FID (resolution > 300,000) for regular DOM, a shorter FID (~ 1 s) for small metabolites with low initial m/z (~ 50–100), and a longer FID (resolution > 500,000) for heteroatom-enriched DOM.","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 7","pages":"509-521"},"PeriodicalIF":2.1,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635004","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

Calibration of the transparency tube for estimating turbidity in estuarine systems 河口系统浊度估算用透明管的校正

IF 2.1 3区地球科学

Limnology and Oceanography: Methods Pub Date : 2025-05-29 DOI: 10.1002/lom3.10695

Makenna Thompson, Erik Smith, James L. Pinckney

{"title":"Calibration of the transparency tube for estimating turbidity in estuarine systems","authors":"Makenna Thompson, Erik Smith, James L. Pinckney","doi":"10.1002/lom3.10695","DOIUrl":"https://doi.org/10.1002/lom3.10695","url":null,"abstract":"Turbidity, quantified in turbidity units (nephelometric or formazin), is a common and valid measure of water quality related to transparency. A transparency tube (TT) is an economical tool developed to estimate water clarity as an alternative to the Secchi disk, but it is also frequently used to estimate turbidity. Although the relationship between TT measures and turbidity is well characterized for freshwater river and lake systems, this relationship has not been tested for estuarine waters. The objective of the current study was to empirically determine the TT–turbidity relationship for estuarine waters in coastal South Carolina (SC) and compare these results with the traditional freshwater system conversions. We obtained 107 measurements of TT depth, turbidity, total suspended solids, colored dissolved organic matter absorbance, Secchi depth, and chlorophyll a at 22 estuarine locations in SC over a 1-year period. Linear regressions provide conversion equations that can be applied to SC estuarine waters. The TT–turbidity relationship for estuaries was compared with freshwater systems. Our results suggest that the slope of the relationship differs between systems (−1.11 vs. −1.41), resulting in different turbidity estimates for TT measurements for estuarine vs. inland waters. We propose a combined conversion table incorporating estuarine and freshwater (riverine and lacustrine) systems. A TT–turbidity conversion for coastal SC and similar estuarine waters significantly benefits current water quality programs and citizen science groups by producing more accurate turbidity estimates for screening and routine monitoring efforts.","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 7","pages":"500-508"},"PeriodicalIF":2.1,"publicationDate":"2025-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lom3.10695","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635666","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}

引用次数: 0

A novel, self-contained benthic chamber design for conducting freshwater ecosystem experiments 一种新颖的、独立的底栖生物室设计，用于进行淡水生态系统实验

IF 2.1 3区地球科学

Limnology and Oceanography: Methods Pub Date : 2025-05-20 DOI: 10.1002/lom3.10692

Jonathan W. Lopez, Matthew B. Lodato, Taylor C. Michael, Lauren M. Morris, Carla L. Atkinson

{"title":"A novel, self-contained benthic chamber design for conducting freshwater ecosystem experiments","authors":"Jonathan W. Lopez, Matthew B. Lodato, Taylor C. Michael, Lauren M. Morris, Carla L. Atkinson","doi":"10.1002/lom3.10692","DOIUrl":"https://doi.org/10.1002/lom3.10692","url":null,"abstract":"We present a newly developed design for a self-contained benthic chamber for conducting in situ ecosystem experiments in streams, with a focus on biogeochemical processes such as ecosystem metabolism and nutrient cycling. Our design expands upon smaller, portable chamber designs and is meant to answer questions at larger scales. These new chambers allow for a high level of experimental control in the field and can be used to generate spatially explicit data regarding ecosystem processes and to test mechanistic hypotheses. They are built to be deployed within the stream over periods of weeks to months and to withstand natural hydraulic forces of the benthic zone. First, we describe the materials and steps that are needed to construct these chambers in detail. Then, we report the methods and results of a multi-part, diagnostic field study meant to demonstrate the performance and utility of the design. We quantified solute dynamics using a conservative tracer injection, then we estimated ecosystem metabolism across the study site and performed nutrient additions. We detected asymptotic declines in tracer concentrations, calculated nutrient removal rates, and mapped hotspots of ecosystem metabolism. Flow velocity and water depth imposed limitations, but with appropriate methodological forethought these limitations can be minimized. The capacity of our design to accommodate complex, three-dimensional habitats and macrofauna, along with the capability to generate spatially explicit data, are the main advances we present. These advances provide a novel method whereby motivated users can connect mechanistic hypothesis testing with natural ecological processes through ecosystem-level field experiments.","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 7","pages":"451-466"},"PeriodicalIF":2.1,"publicationDate":"2025-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635259","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

Trace analysis of volatile fatty acids in marine waters using modern high-pressure ion chromatography 现代高压离子色谱法对海水中挥发性脂肪酸的痕量分析

IF 2.1 3区地球科学

Limnology and Oceanography: Methods Pub Date : 2025-05-19 DOI: 10.1002/lom3.10686

Samuel I. Pereira, Bo Emilsson, Eoghan P. Reeves

{"title":"Trace analysis of volatile fatty acids in marine waters using modern high-pressure ion chromatography","authors":"Samuel I. Pereira, Bo Emilsson, Eoghan P. Reeves","doi":"10.1002/lom3.10686","DOIUrl":"https://doi.org/10.1002/lom3.10686","url":null,"abstract":"Volatile fatty acids (VFAs) are key intermediates in carbon transformation in marine environments and feature widely in models for a hydrothermal origin of life. Quantifying VFAs in hydrothermal fluids is challenging due to their trace concentrations and the high inorganic ion loads of these matrices. Previous methods often rely on manual sample pre-treatment or complex instrumentation (e.g., mass spectrometry), increasing contamination risks, consumable use, and costs. To circumvent such challenges, we developed a simplified quantification method for trace VFAs in seawater-like matrices using a modern high-pressure ion chromatography (HPIC) system. This approach utilizes single-dimension ion exchange chromatography with conductivity detection alone, and a choice of two analytical column options to separate formate, acetate, propionate, butyrate, valerate, pyruvate, and lactate (measured as ∑anion) from inorganic anions. Modern HPIC systems, in addition to being versatile for other analytes (e.g., cations, nutrients), enable higher peak resolution and increased ion exchange capacity, and our tests show this allows for significantly greater trace VFA sensitivity than previous techniques. With careful sample handling and contamination control, our method achieves better absolute limits of detection for smaller sample requirements (≤ 0.3 mL), statistically determined to be below 10 ppb (~ 0.05 μmol/kg for ∑formate, ~ 0.03 μmol/kg for ∑acetate). Additionally, our study provides detailed insights into limiting VFA contamination sources, as well as their stability in storage. Initial analysis of hydrothermal fluids from the Arctic Mid-Ocean Ridges reveals formate (0.6–7.3 μmol/kg) controlled by metastable CO2–H2–HCOOH equilibrium, and unexpectedly low acetate (2.6–5.8 μmol/kg), likely reflecting competition between thermogenic formation and stability.","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 6","pages":"389-412"},"PeriodicalIF":2.1,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144245021","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

Monitoring Euplotes species dynamics in mixed experiments using genetic markers for quantitative polymerase chain reaction 利用遗传标记进行定量聚合酶链反应，监测混合实验中的常体物种动态

IF 2.1 3区地球科学

Limnology and Oceanography: Methods Pub Date : 2025-05-10 DOI: 10.1002/lom3.10691

Verena Bamberger, Ralph Tollrian, Linda C. Weiss

{"title":"Monitoring Euplotes species dynamics in mixed experiments using genetic markers for quantitative polymerase chain reaction","authors":"Verena Bamberger, Ralph Tollrian, Linda C. Weiss","doi":"10.1002/lom3.10691","DOIUrl":"https://doi.org/10.1002/lom3.10691","url":null,"abstract":"Ciliates are widespread and play a major role in ecosystems as they form an important link between primary producers and higher trophic levels. They have been used as a classic model to study predator–prey interactions of co-evolutionary processes. In our experimental system, predators and prey interact dynamically, with prey exhibiting predator-induced defenses and predators potentially adapting through offensive strategies, both of which influence population dynamics. When analyzing population dynamics in similar ciliate species, individuals must be accurately identified and counted. Morphologically, the genus Euplotes is generally identified by the arrangement of cilia and cirri and the position of the macronucleus and micronucleus. This requires expensive and laborious cell counters and time-consuming staining methods. Furthermore, staining methods are not ideal for determining cell numbers, as individual cells may be lost during staining processes. As ciliates are unicellular organisms, we used DNA quantity to determine the number of individuals. We identified unique sequences of three Euplotes species: Euplotes octocarinatus, Euplotes daidaleos, and Euplotes aediculatus using random amplified polymorphic DNA (RAPD) fingerprinting. Using these sequences, we designed species-specific primers for quantitative polymerase chain reaction and generated corresponding standard curves based on microscopic cell counts. Using this method, we are now able to determine cell counts in unknown samples of different Euplotes species within a single experimental system and monitor population growth rates of one or even several species simultaneously. Additionally, using RAPD fingerprinting enables the identification of unique genetic sequences, allowing differentiation between clones of the same species and facilitating measurement of their population growth rates in mixed experiments.","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 7","pages":"442-450"},"PeriodicalIF":2.1,"publicationDate":"2025-05-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lom3.10691","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635461","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}

引用次数: 0

Meiofauna investigation and taxonomic identification through imaging—a game of compromise 通过影像调查和分类鉴定——一个妥协的游戏

IF 2.1 3区地球科学

Limnology and Oceanography: Methods Pub Date : 2025-04-29 DOI: 10.1002/lom3.10690

Valentin Foulon, Abdesslam Benzinou, Kamal Nasreddine, Abdul Qayyum, Edwin Daché, Valentine Foulquier, Catherine Borremans, Marine Malloci, Colomban De Vargas, Daniela Zeppilli

{"title":"Meiofauna investigation and taxonomic identification through imaging—a game of compromise","authors":"Valentin Foulon, Abdesslam Benzinou, Kamal Nasreddine, Abdul Qayyum, Edwin Daché, Valentine Foulquier, Catherine Borremans, Marine Malloci, Colomban De Vargas, Daniela Zeppilli","doi":"10.1002/lom3.10690","DOIUrl":"https://doi.org/10.1002/lom3.10690","url":null,"abstract":"Imaging methods have developed rapidly in recent decades, opening new opportunities for taxonomy and biodiversity studies of marine organisms. In particular, the microscopic size range, which used to be challenging to study due to time-consuming preparation and observation steps, now benefits from high-throughput quantitative imaging methods and the development of fast high-resolution microscopy approaches. Meiofauna, interstitial sediment animals ranging from 20 μm to 1 mm, are important components of ecosystems. These organisms can serve as bioindicators, and the group as a whole holds immense potential for the discovery of new species. However, protocols for studying meiobenthos are highly time-consuming, which helps explain why this group is understudied. We tested five imaging techniques, ranging from low to high resolution, that could accelerate hard-bodied meiofauna studies, both for ecology and species description, and address the gap in our understanding of this part of marine life. Thus, two flow imaging modalities (in line holographic microscopy and classic optic microscopy), a semi-automated microscopy acquisition procedure, and two three-dimensional (3D) fluorescence microscopy protocols were used. We examined the classic compromises of imaging, including resolution, throughput, and data volume, to evaluate the potential benefits of using such techniques for meiofaunal studies. For ecological surveys, flow imaging could benefit meiobenthos studies, but resolution remains a limiting factor. For taxonomic description, 3D fluorescent imaging added relevant information, considering the time required for preparation and acquisition. The semi-automated motorized microscopy procedure could be used for both purposes according to the versatility of the system.","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 7","pages":"482-499"},"PeriodicalIF":2.1,"publicationDate":"2025-04-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144635662","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

Assessing the applicability of sequential eye lens stable isotope analysis for reconstructing dietary histories in amphibians 评估序贯眼晶状体稳定同位素分析在重建两栖动物饮食史中的适用性

IF 2.1 3区地球科学

Limnology and Oceanography: Methods Pub Date : 2025-04-26 DOI: 10.1002/lom3.10689

Arisa Shiga, Jun Matsubayashi, Nanako O. Ogawa, Naohiko Ohkouchi, Noriko Iwai

{"title":"Assessing the applicability of sequential eye lens stable isotope analysis for reconstructing dietary histories in amphibians","authors":"Arisa Shiga, Jun Matsubayashi, Nanako O. Ogawa, Naohiko Ohkouchi, Noriko Iwai","doi":"10.1002/lom3.10689","DOIUrl":"https://doi.org/10.1002/lom3.10689","url":null,"abstract":"Retrospective isotope analysis using metabolically inert tissues is a powerful tool for reconstructing historical environmental conditions experienced by animals. Although this technique has been successfully applied to fish and squids using eye lenses, its applicability to metamorphosing organisms, such as amphibians, across multiple life-history stages has not been thoroughly assessed. In this study, we examined whether stable isotope ratios in frog eye lenses reflect dietary data from both the larval and post-metamorphic stages through feeding trials of two species, Rana ornativentris and Babina subaspera, using diets with distinct δ13C values. Additionally, we analyzed samples collected from the wild and assessed the potential future use of this method. Our feeding trials demonstrated that δ13C values in the central and outer lens sections were closely aligned with the larval and adult food, respectively, confirming the applicability of the method. The transition point of stable isotope ratios was closely aligned with the actual metamorphosis point, indicating that this method can effectively identify metamorphosis. However, the two wild specimens exhibited no discernible patterns in isotope ratios across their life stages. This indicates that applying this method in the field requires careful selection of the environmental conditions and a comprehensive understanding of the stable isotope ratios of potential food sources.","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 5","pages":"336-345"},"PeriodicalIF":2.1,"publicationDate":"2025-04-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143950226","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

MARS: Programmable multipurpose auto-release system for aquatic observations 用于水生观测的可编程多用途自动释放系统

IF 2.1 3区地球科学

Limnology and Oceanography: Methods Pub Date : 2025-04-25 DOI: 10.1002/lom3.10688

Marko Radeta, João Gama Monteiro, João Pestana, Dinarte Vieira, Pedro Abreu, Rodrigo Silva, Susanne Schäfer, Patrício Ramalhosa, Ana Lopez Martos, Bruno Loureiro, Nuno Queiroz, Rui Seabra, Fernando P. Lima, João Canning-Clode

{"title":"MARS: Programmable multipurpose auto-release system for aquatic observations","authors":"Marko Radeta, João Gama Monteiro, João Pestana, Dinarte Vieira, Pedro Abreu, Rodrigo Silva, Susanne Schäfer, Patrício Ramalhosa, Ana Lopez Martos, Bruno Loureiro, Nuno Queiroz, Rui Seabra, Fernando P. Lima, João Canning-Clode","doi":"10.1002/lom3.10688","DOIUrl":"https://doi.org/10.1002/lom3.10688","url":null,"abstract":"Aquatic biodiversity assessments are often labor-intensive due to the large size of the equipment and the complex logistics of sea vessel operations. Traditional drift and drop cameras are typically tethered to the surface, causing cable and line clutter on sea vessels. At the same time, landers rely on auto-release mechanisms that use costly acoustic signals or inaccurate galvanic reactions. We introduce a reusable, novel, and low-cost Multipurpose Auto-Release System, a versatile and programmable solution for diverse payloads and applications in shallow and mesophotic waters. Building on existing drop-cam and Baited Remote Underwater Video System techniques, we enhance them with natural ballasts and an electronically controlled timed-release mechanism, which is programmed via a smartphone app using Near Field Communication. Our technique allows tetherless retrieval from small sea vessels at the sea surface. This innovation simplifies aquatic monitoring logistics by eliminating the need for surface buoys or equipment retrieval from the seabed during each deployment. Our approach also advances benthic and deep-sea marine biodiversity assessments by enabling easy systems deployment and recapture without pingers. We validated the system through 10 seawater tests, reaching depths of 278 m, accumulating 6 h of submerged data collection, and 17 d during continuous water immersion. We provide a detailed guide for building this robust, reusable, user-friendly tool for diverse aquatic monitoring assessments. Additionally, we share key lessons learned, paving the way toward more democratized, customizable, and widely accessible applications capable of reaching the deepest seas.","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 6","pages":"376-388"},"PeriodicalIF":2.1,"publicationDate":"2025-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lom3.10688","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144245035","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}

引用次数: 0

Enhancing sampling of dissolved N2O in aquatic systems: Field-deployable automated gas bag collection system 加强水生系统中溶解N2O的采样：现场可部署的自动气囊收集系统

IF 2.1 3区地球科学

Limnology and Oceanography: Methods Pub Date : 2025-04-22 DOI: 10.1002/lom3.10687

Mohammad Arar, Timothy J. Clough, Naomi S. Wells

{"title":"Enhancing sampling of dissolved N2O in aquatic systems: Field-deployable automated gas bag collection system","authors":"Mohammad Arar, Timothy J. Clough, Naomi S. Wells","doi":"10.1002/lom3.10687","DOIUrl":"https://doi.org/10.1002/lom3.10687","url":null,"abstract":"Measuring dissolved nitrous oxide (N2O), a potent greenhouse gas and contributor to ozone depletion, is essential for understanding its aquatic dynamics and informing climate mitigation and emission estimates. Dissolved N2O concentration measurements typically involve headspace equilibration of water samples in sealed containers, followed by gas chromatography analysis. This manual method is labor-intensive and often requires toxic preservatives. Alternatively, air-water exchangers coupled with laser analyzers provide high-precision continuous measurements but lack sample storage capabilities and require frequent relocation and setup to capture spatiotemporal variations. We developed an automated gas bag (AGB) collection system for collecting N2O samples (AGB-N2O) from discrete water samples, which could then be analyzed for concentration using laser analyzers. This method combines the field-friendly sample collection and storage of the manual method with the precision of exchangers and laser analyzers. Field experiments tested four setups of exchangers with varying internal volumes (2 L vs. 1 L) and water flow rates (small nozzle: 0.75 L min−1 vs. medium nozzle: 3 L min−1) at sites with low vs. high N2O concentrations (13 nM vs. 95 nM). The 2-L exchanger with a medium nozzle achieved the fastest equilibration times of 2.25 and 0.08 min for high and low N2O sites, respectively. The AGB-N2O showed comparable results to the manual method for measuring dissolved N2O concentrations (p > 0.05). However, the AGB-N2O demonstrated significantly lower standard deviations, indicating higher precision and consistency. These findings demonstrate the suitability of the AGB-N2O for diverse aquatic environments, offering reliable and efficient N2O measurements.","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 6","pages":"363-375"},"PeriodicalIF":2.1,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lom3.10687","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144245002","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}

引用次数: 0