Limnology and Oceanography: Methods最新文献

{"title":"Assessing the applicability of sequential eye lens stable isotope analysis for reconstructing dietary histories in amphibians","authors":"Arisa Shiga,&nbsp;Jun Matsubayashi,&nbsp;Nanako O. Ogawa,&nbsp;Naohiko Ohkouchi,&nbsp;Noriko Iwai","doi":"10.1002/lom3.10689","DOIUrl":"https://doi.org/10.1002/lom3.10689","url":null,"abstract":"<p>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, <i>Rana ornativentris</i> and <i>Babina subaspera</i>, using diets with distinct <i>δ</i>¹³C 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.</p>","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}

{"title":"Particulate inorganic carbon in the ocean: Evaluation of discrete sampling protocols","authors":"Catherine Mitchell,&nbsp;Jelena Godrijan","doi":"10.1002/lom3.10683","DOIUrl":"https://doi.org/10.1002/lom3.10683","url":null,"abstract":"<p>This study evaluates the impact of sampling protocols on the measurement of particulate inorganic carbon (PIC) in ocean waters, an essential component for understanding the global carbon cycle and climate regulation. The study compares four protocols for estimating PIC in discrete water column samples, focusing on the effects of filter pore size (0.4 vs. 0.8 <i>μ</i>m) and rinsing agents (pH-adjusted MilliQ water with NH₄OH vs. potassium tetraborate buffer). Five coccolithophore strains were selected to represent variations in PIC content resulting from species-specific differences in coccolith mass, coccolith number per cell, and life cycle phase. Discrete samples were analyzed using inductively coupled plasma mass spectrometry. Statistical analyses show no significant differences in PIC concentrations between protocols, filter types, or rinsing agents, confirming the robustness and precision of the measurement method. In addition, the non-calcifying strain provided insights into the measurement uncertainty and enabled us to quantify the precision of the sampling method. These results suggest that researchers can use any tested protocol without compromising data quality. This will improve the reliability and comparability of PIC measurements and contribute to a more precise understanding of ocean carbon dynamics and climate regulation.</p>","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 5","pages":"326-335"},"PeriodicalIF":2.1,"publicationDate":"2025-03-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lom3.10683","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949779","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":"DISCO: A low-cost device-instrumented Secchi disk for water clarity observations","authors":"Gaia Donini,&nbsp;Sebastiano Piccolroaz","doi":"10.1002/lom3.10684","DOIUrl":"https://doi.org/10.1002/lom3.10684","url":null,"abstract":"<p>Water clarity regulates irradiance penetration in aquatic environments, influencing physical and biological dynamics: irradiance penetration affects heat transfer in the water column and provides energy through photosynthetically active radiation (PAR) in the euphotic zone, which is vital for light-dependent organisms. The ability to accurately assess water clarity is therefore important in several aquatic science contexts, from data analysis and process interpretation to modeling. Common metrics used to quantify water clarity include the vertical irradiance attenuation coefficient <span></span><math>\u0000 <mrow>\u0000 <mi>K</mi>\u0000 </mrow></math>, a measure of irradiance penetration, and the Secchi disk depth (<span></span><math>\u0000 <mrow>\u0000 <msub>\u0000 <mi>z</mi>\u0000 <mi>SD</mi>\u0000 </msub>\u0000 </mrow></math>), a measure of water visibility. The enduring simplicity and low cost of the Secchi disk has made it a global standard for measuring water clarity for almost two centuries. In contrast, <span></span><math>\u0000 <mrow>\u0000 <mi>K</mi>\u0000 </mrow></math> is typically determined using expensive instruments that measure underwater irradiance profiles. This highlights the need for innovative, cost-effective methods that integrate both types of measurements. Here we present DISCO, a low-cost, easy-to-build instrument that retains the traditional appearance of a Secchi disk, and is equipped with photoresistors (also known as light-dependent resistors, LDRs) both looking upwards and downwards for planar irradiance measurements. DISCO is also equipped with low-cost temperature and pressure sensors, all connected to an ArduinoUNO board. DISCO was tested in two mountain lakes together with high resolution PAR, temperature and pressure sensors to calibrate the LDRs and validate its performance. The results show that the proposed instrument is able to measure the irradiance attenuation coefficients with an error of less than 10<span></span><math>\u0000 <mrow>\u0000 <mo>%</mo>\u0000 </mrow></math> compared to the reference PAR sensor.</p>","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 5","pages":"346-361"},"PeriodicalIF":2.1,"publicationDate":"2025-03-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lom3.10684","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143950279","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":"Fast responses, rich insights: Optimizing experimental stream studies using periphyton for comprehensive environmental assessment","authors":"Luciane Ayres Castro Reis,&nbsp;Gilberto Fonseca Barroso","doi":"10.1002/lom3.10681","DOIUrl":"https://doi.org/10.1002/lom3.10681","url":null,"abstract":"<p>Experimental streams (ESs) are enclosures of fluvial ecosystems designed as flume microcosms to simulate flowing waters and assess environmental disturbances on aquatic communities' structure and function under controlled conditions. This study presents an ES system that combines ecological relevance with reliability in a compact design, offering rapid responses to iron ore tailings. The system used periphyton biofilm as a bioindicator in a recirculating flume microcosm over 65 d. Periphyton is a key bioindicator, representing critical aquatic metabolic processes such as primary production. The system includes artificial glass channels, microscope slide substrates, and recirculating pumps. It was developed with replicates, three controls, and three treatments, each consisting of a main channel and a water reservoir, for a total volume of 10.0 L. Six sampling campaigns evaluated periphyton biofilm and water quality indicators under acute, short, and long-term exposures. The system's reliability is ensured by standardizing setup conditions, maintaining river water properties, ensuring uniform flow, and standardizing slide sampling. Realism is achieved by renewing large water volumes, regular inoculation of periphyton propagules, and the appropriate sampling frequency for periphyton and water quality. The results showed that the ES, a simple and low-cost system (US$569), was sensitive to indicators throughout the exposure period. This approach is practical for assessing various aquatic stressors.</p>","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 5","pages":"309-325"},"PeriodicalIF":2.1,"publicationDate":"2025-03-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lom3.10681","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143950259","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":"Retrieving vertical phytoplankton functional types in the South China Sea and adjacent Taiwan Strait based on phytoplankton absorption spectra and machine learning","authors":"Qing Zhu,&nbsp;Zhongping Lee,&nbsp;Wupeng Xiao,&nbsp;Bangqin Huang,&nbsp;Gong Lin","doi":"10.1002/lom3.10679","DOIUrl":"https://doi.org/10.1002/lom3.10679","url":null,"abstract":"<p>Phytoplankton functional types (PFTs) found in natural aquatic environments play different roles in the biogeochemical cycles of different elements. However, commonly used methods for identifying PFTs have inherent limitations. In this study, based on a large dataset (1747 samples) collected from 2004 to 2019 in the South China Sea and adjacent Taiwan Strait, which had concurrent measurements of the spectral absorption coefficient of phytoplankton and chlorophyll <i>a</i> concentration of nine PFTs (PFTs_Chla), along with depth and time information, a reliable support vector regression (SVR) model was developed to retrieve these nine PFTs_Chla in the water column. These PFTs included diatoms, dinoflagellates, haptophytes_8, haptophytes_6, chlorophytes, cryptophytes, <i>Prochlorococcus</i>, <i>Synechococcus</i>, and prasinophytes. The independent validation results indicated that the SVR model outperformed the traditional PFTs_Chla retrieval algorithms, with an average mean bias of −14.2%, an average mean absolute unbiased relative difference of 60.3%, and an average coefficient of determination of 0.56. The predicted PFTs_Chla values and their error distributions in the water column were subsequently analyzed. Finally, the SVR model was found to be applicable to most PFTs_Chla retrieval in the East China Sea.</p>","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 4","pages":"223-245"},"PeriodicalIF":2.1,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749659","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":"FISH, a new tool for in situ preservation of RNA in tissues of deep-sea mobile fauna","authors":"Valérie Cueff-Gauchard,&nbsp;Johanne Aubé,&nbsp;Jean-Romain Lagadec,&nbsp;Laurent Bignon,&nbsp;Jean-Pierre Lafontaine,&nbsp;Iván Hernández-Ávila,&nbsp;Nathalie Marsaud,&nbsp;Bruce Shillito,&nbsp;Louis Amand,&nbsp;Erwan G. Roussel,&nbsp;Marie-Anne Cambon","doi":"10.1002/lom3.10677","DOIUrl":"https://doi.org/10.1002/lom3.10677","url":null,"abstract":"<p>Accessing the metabolic functioning of deep-sea animals in situ remains a technological challenge as the recovery time of samples is incompatible with the short lifespan of such molecules as mRNAs. Tools able to preserve RNA in situ exist, but they are incompatible with the study of mobile fauna. Here, we describe a new sampling tool, named FISH (fixer in situ of homogenized substrates), implemented on a submersible and equipped with a number of new specific features to collect and preserve in situ tissue of mobile fauna. Connected to the suction pump of a submersible, the FISH sampler incorporates a sampling bowl to which two bottles of a preservative reagent are attached, a suction hose, and a support containing a motor connected to the sampling bowl by a magnetic coupling system. We used the deep-sea hydrothermal shrimp <i>Rimicaris exoculata</i> from the Mid-Atlantic Ridge as a model to test the suitability of our new tool. The FISH sampler was compared to two other sampling methods, which use a metatranscriptomic approach targeting microbial communities associated with cephalothorax symbionts. RNA quality, gene assignment, and taxonomic and gene function diversity showed differences between in situ and on-board preservation of tissues. Of the alternative sampling methods tested, the suction sampler was clearly not suitable for RNA-based studies, while pressurized recovery showed results closer to the sample quality obtained with FISH sampling. The FISH sampler has therefore demonstrated to be a cost-effective and reliable tool to efficiently preserve RNA recovered from deep-sea environments.</p>","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 4","pages":"273-292"},"PeriodicalIF":2.1,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lom3.10677","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749822","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":"Estimating phytoplankton primary production by coupling pulse amplitude modulation and incubation methods","authors":"Yichong Wang,&nbsp;Wupeng Xiao,&nbsp;Chengwen Xue,&nbsp;Yaqin Zhang,&nbsp;Chao Xu,&nbsp;Weinan Li,&nbsp;Mingwang Xiang,&nbsp;Chun Yang,&nbsp;Jixin Chen,&nbsp;Bangqin Huang","doi":"10.1002/lom3.10678","DOIUrl":"https://doi.org/10.1002/lom3.10678","url":null,"abstract":"<p>Pulse amplitude modulation (PAM) fluorometry provides high-resolution and high-frequency primary production (PP) estimates, crucial for understanding and managing dynamic ecosystems such as estuaries. However, traditional PAM-derived PP estimations often overlook the variability of the photosynthetic quotient and the dynamics of chlorophyll <i>a</i>, leading to uncertainties. This study introduced an innovative method for estimating the PP of natural phytoplankton communities using the rapid light curve of PAM measurements. Validation using ¹⁴C incorporation and oxygen techniques in two subtropical estuaries demonstrated a strong linear relationship between PAM-derived PP and measured oxygen evolution rates (<i>R</i>² = 0.76, <i>p</i> &lt; 0.001) and carbon fixation rates (<i>R</i>² = 0.94, <i>p</i> &lt; 0.001). While the dynamics of chlorophyll <i>a</i> had minimal impact on hourly PAM-derived PP estimations, they caused significant deviations on daily time scales, influenced by sampling times. Predicting photosynthetic quotient values based on salinity (<i>R</i>² = 0.34, <i>p</i> &lt; 0.05) allowed for expanded temporal and spatial PP estimations. Seasonal PP patterns in the Jiulong River Estuary, Xiamen Bay, Zhangjiang Estuary, and Dongshan Bay revealed the highest PP in summer, followed by spring, with similar levels in autumn and winter. Using these surface measurements, annual phytoplankton carbon fixation fluxes were estimated through the entire water column across the four regions. This method provides a more comprehensive understanding of PP dynamics, highlighting its potential for frequent application in small-scale valuable ecosystems like estuaries and bays to better assess their ecological functions and biogeochemical cycles.</p>","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 4","pages":"293-308"},"PeriodicalIF":2.1,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749905","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":"Accurate estimation of photosynthetic available radiation from multispectral downwelling irradiance profiles","authors":"Jaime Pitarch,&nbsp;Edouard Leymarie,&nbsp;Vincenzo Vellucci,&nbsp;Luca Massi,&nbsp;Hervé Claustre,&nbsp;Antoine Poteau,&nbsp;David Antoine,&nbsp;Emanuele Organelli","doi":"10.1002/lom3.10673","DOIUrl":"https://doi.org/10.1002/lom3.10673","url":null,"abstract":"&lt;p&gt;Photosynthetic available radiation (PAR) is the light usable by photosynthetic organisms. Photosynthetic available radiation measurements at depth are required to quantify the light availability for primary production. Direct PAR measurements may be measured with full-spectrum quantum sensors for the range 400 to 700 nm. When spectrally resolved light is measured, as for the downwelling irradiance spectrum &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;E&lt;/mi&gt;\u0000 &lt;mi&gt;d&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;&lt;/math&gt;, PAR may be computed by numerically integrating &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;E&lt;/mi&gt;\u0000 &lt;mi&gt;d&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;&lt;/math&gt; within those limits. As radiation varies across a spectral continuum, &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;E&lt;/mi&gt;\u0000 &lt;mi&gt;d&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;&lt;/math&gt; needs to be resolved at a sufficiently large number of bands, to provide an unbiased PAR estimate. When &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;E&lt;/mi&gt;\u0000 &lt;mi&gt;d&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;&lt;/math&gt; is available at a small number of spectral bands, as for multispectral &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;E&lt;/mi&gt;\u0000 &lt;mi&gt;d&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;&lt;/math&gt; sensors, it is still possible to numerically integrate &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;E&lt;/mi&gt;\u0000 &lt;mi&gt;d&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;&lt;/math&gt;, but the estimation will contain errors. Here, we propose a method that delivers unbiased PAR estimates, based on two-layer neural networks, formulable in a small number of matrix equations, and thus exportable to any software platform. The method was calibrated with a dataset of hyperspectral &lt;span&gt;&lt;/span&gt;&lt;math&gt;\u0000 &lt;mrow&gt;\u0000 &lt;msub&gt;\u0000 &lt;mi&gt;E&lt;/mi&gt;\u0000 &lt;mi&gt;d&lt;/mi&gt;\u0000 &lt;/msub&gt;\u0000 &lt;/mrow&gt;&lt;/math&gt; acquired by new types of BioGeoChemical (BGC)-Argo floats deployed in a variety of open ocean locations, representative of a wide range of bio-optical properties. This procedure was repeated for several band configurations, including those existing on multispectral radiometers presently the standard for the BGC-Argo fleet. Validation results against independent data were highly satisfactory, displaying minimal uncertainties across a wide PAR range, with the performance varying as a function of each sensor configuration, overall supporting the operational implementation in the Argo program. Model codes are findable at https://gi","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 4","pages":"261-272"},"PeriodicalIF":2.1,"publicationDate":"2025-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lom3.10673","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749982","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":"Picturing plankton: Complementing net-based plankton community assessments with optical imaging across diverse marine environments","authors":"Anouk Ollevier,&nbsp;Jonas Mortelmans,&nbsp;Wieter Boone,&nbsp;Klaas Deneudt,&nbsp;Marleen De Troch,&nbsp;Roeland Develter,&nbsp;Cedric Goossens,&nbsp;Lorenz Meire,&nbsp;Klas Ove Möller,&nbsp;Leandro Ponsoni,&nbsp;Pascal I. Hablützel","doi":"10.1002/lom3.10674","DOIUrl":"https://doi.org/10.1002/lom3.10674","url":null,"abstract":"<p>In recent years, optical imaging has emerged as a promising tool for in situ observations of plankton. In this study, we aimed to compare the plankton community estimates obtained from a Video Plankton Recorder (VPR) imaging device with net-based approaches. By collecting VPR and net samples in clear waters with large-sized plankton and eutrophic waters with small-sized plankton, spatial and temporal patterns in plankton densities and community composition were compared. Furthermore, it allowed the evaluation of the performance of imaging methods under diverse hydrographic conditions. We observed pronounced spatial differences in density estimates. In the eutrophic site, the WP2 net densities consistently surpassed those from a VPR, while in the clear water site the observed densities of the VPR and a MultiNet were more similar. Variations in water column turbidity, plankton body size, plankton nets and their mesh size, and the total sampled water volume were found to likely play a role in the observed inconsistencies between the sampling sites. The results suggested that a VPR is particularly well-suited for use in clear waters inhabited by large-sized plankton. The VPR demonstrated potential in enhancing density estimates of fragile (<i>Phaeocystis</i>) and gelatinous taxa (Cnidaria and Ctenophora) in specific environments being non-invasive. Overall, the VPR and other optical imaging devices show valuable insights into zooplankton ecology and distribution, complementing density estimates of traditional net sampling methods, and enhancing our understanding of the role of zooplankton in marine ecosystems.</p>","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 4","pages":"246-260"},"PeriodicalIF":2.1,"publicationDate":"2025-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143749524","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":"Deep learning-based characterization of underwater methane bubbles using simple dual camera platform","authors":"Yann Marcon,&nbsp;Marie Stetzler,&nbsp;Bénédicte Ferré,&nbsp;Eberhard Kopiske,&nbsp;Gerhard Bohrmann","doi":"10.1002/lom3.10672","DOIUrl":"https://doi.org/10.1002/lom3.10672","url":null,"abstract":"<p>Seabed gas and oil emissions appear as bubble plumes ascending through the water column in various environments. Understanding bubble characteristics—size, rise speed—is important for estimating escape rates of fluids like methane, oil, and carbon dioxide. However, measuring underwater gas bubbles is challenging, often requiring expensive specialized equipment. This study presents a novel methodology using two calibrated consumer-grade cameras to estimate bubble size distribution, rise velocities, and corresponding gas or oil flow rates. Our approach, named BURST (Bubble Rise and Size Tracking), uses a trained neural network for automated bubble detection in diverse camera footage, effectively analyzing under varying lighting conditions and visibility, without requiring a uniform backlit background for bubble identification. Post-detection, bubbles are tracked and synchronized between the cameras, with three-dimensional triangulation used to deduce sizes and rise speeds, enabling flow rate calculations. We demonstrate the efficacy of our methodology through basin experiments capturing methane bubble plumes with controlled flow rates. Additionally, we successfully apply this methodology to existing footage from natural methane emission sites in the Hopendjupet seeps within the central Barents Sea, measuring methane flow rates of approximately 46 and 24 mmol CH₄ min⁻¹ at water depths of 327 and 341 m, respectively. These results underscore the practical applicability of BURST in complex underwater environments without disrupting natural bubble flow. By utilizing readily available equipment, BURST enables reliable bubble measurements in challenging real-world conditions, including the analysis of legacy footage not initially intended for bubble flow rate quantification. The BURST python script is available at https://github.com/BUbbleRST/BURST/.</p>","PeriodicalId":18145,"journal":{"name":"Limnology and Oceanography: Methods","volume":"23 3","pages":"155-175"},"PeriodicalIF":2.1,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lom3.10672","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143571196","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}