Limnology and Oceanography最新文献

{"title":"Predicting river ecosystem metabolism across large environmental gradients: Drivers and temporal dependencies in the Iberian Peninsula","authors":"Amaia A. Rodeles, Francisco J. Peñas, Maite Arroita, José Barquín","doi":"10.1002/lno.70019","DOIUrl":"https://doi.org/10.1002/lno.70019","url":null,"abstract":"River ecosystem metabolism plays a significant role in the global carbon cycle. However, the limited spatial or temporal scale of most river metabolism studies hinders our ability to draw general patterns, identify common drivers, and make reliable global predictions. We developed Random Forest models for predicting daily metabolism rates using a large database of more than 100 river reaches across the Iberian Peninsula covering a large environmental gradient. As potential drivers, we included static variables (e.g., catchment area, distance to the sea), anthropogenic factors (e.g., land uses), and short‐term dynamic variables (e.g., light, water temperature, discharge) averaged over different periods (from 0 to 40 d) to explore the role of shorter vs. longer‐term environmental control on daily river metabolism rates. Both daily gross primary production and ecosystem respiration rates responded more strongly to average environmental conditions over the previous 40 d than to daily values. The 40‐d average random forest models explained up to 77% of gross primary production and 82% of ecosystem respiration variance. The most important drivers of GPP were stage (depth), distance to the sea, and light, while the main predictors of ER were stage and GPP. Dynamic variables were generally the most important drivers of daily metabolic rates, although static ones such as distance to the sea also played a role. Our results indicate that temporal patterns in river metabolism are influenced by a combination of environmental conditions integrated over several weeks, seasonal timing, and to a lesser extent, topology.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"36 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143599551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular activity mediates the composition and assembly of dissolved organic matter in lake sediments","authors":"Shuailong Wen, Ang Hu, Francisco Dini‐Andreote, Lei Han, Shuyu Jiang, Kyoung‐Soon Jang, Jianjun Wang","doi":"10.1002/lno.70015","DOIUrl":"https://doi.org/10.1002/lno.70015","url":null,"abstract":"Lake sediments are hotspots for carbon transformation and burial, where the turnover of dissolved organic matter (DOM), influenced by molecular activity, regulates global carbon cycling. However, the composition of sediment DOM and how its assembly mechanisms are related to molecular activity remain poorly understood. Here, 63 freshwater sediments were collected from tropical to cold temperate climatic zones in China. We explored the molecular composition and assembly of sediment DOM and the underlying mechanisms driven by climate, physicochemical factors, and microbes along the gradient of molecular activity, indicated by the number of potential biochemical transformations in which a molecule is involved. Sediment DOM was dominated by lipid‐ (35%) and lignin‐like compounds (33%), and the latter were enriched as the molecular activity of DOM increased. Besides, the DOM assemblage with higher potential biochemical transformations had greater compositional similarity across different climatic zones and tended to assemble deterministically. Specifically, as the average number of potential biochemical transformations of molecules increased from 0.4 to 14, the assembly of these molecules was structured by a shift from stochastic to deterministic processes, with the latter accounting for ≥ 75% thereafter. Overall, DOM assemblages were primarily structured by physicochemical factors, including sediment total organic carbon and electrical conductivity. As molecular activity increased, however, assemblages were increasingly affected by climate and bacterial communities, consistent with the enhanced complexity of bacterial–molecular networks. Collectively, our study highlights that the turnover of DOM regulated by biotic and abiotic factors is further constrained by the intrinsic molecular activity.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"20 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143599349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transport and retention of microplastic fibers in streams are impacted by benthic algae, discharge, and substrate","authors":"Elizabeth M. Berg, Shannon Speir, Arial J. Shogren, Martha M. Dee, Anna E. S. Vincent, Jennifer L. Tank, John J. Kelly, Timothy J. Hoellein","doi":"10.1002/lno.70003","DOIUrl":"https://doi.org/10.1002/lno.70003","url":null,"abstract":"Microplastics (particles < 5 mm) are pollutants of emerging concern in aquatic ecosystems worldwide. Streams are key sites of microplastic input, retention, and transport, and empirical measurements of microplastic movement in lotic ecosystems are needed to inform global microplastic budgets. However, factors that influence microplastic retention in lotic ecosystems are not well studied. We used particle spiraling metrics to directly measure microplastic retention following pulse releases of polyester fibers using outdoor, experimental streams lined with substrates of varying sizes. We tested the impact of benthic algae, stream discharge, and substrate type on the transport of experimentally added microplastic fibers. We also quantified microplastic retention in and release from the stream benthos after an increase in discharge to simulate a storm event. Microplastic deposition rates were significantly higher with (1) well‐established benthic algal biofilms, (2) higher stream discharge, and (3) larger benthic substrate. The increase in microplastic deposition rates with elevated discharge is opposite the expected trend observed for particulate organic matter, indicating distinct retention processes for microplastics. A rapid increase in discharge in our experimental streams resulted in resuspension of retained microplastic from all substrate types, suggesting that storm events could trigger microplastic release in natural streams. The results from this study provide direct measurements of the magnitude and direction of factors that drive microplastic retention in streams, which will contribute to the parameterization of models for microplastic deposition (and release) at larger spatial and temporal scales for freshwater ecosystems.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"5 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143599548","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Inorganic carbon dynamics and their relation to autotrophic community regime shift over three decades in a large, alkaline river","authors":"Jacob S. Diamond, An Nguyen Truong, Gwenaël Abril, Enrico Bertuzzo, Vincent Chanudet, Raphael Lamouroux, Florentina Moatar","doi":"10.1002/lno.70016","DOIUrl":"https://doi.org/10.1002/lno.70016","url":null,"abstract":"How much of the excess CO<jats:sub>2</jats:sub> in running waters comes from in‐stream respiration of organic carbon? To answer this, we developed a 30‐yr metabolism‐carbonate system database at an hourly resolution for the Loire River, France, a large, alkaline river. We asked the following questions: what are the intra‐annual patterns of in‐stream (“internal”) CO<jats:sub>2</jats:sub> production, what processes drive these patterns, and how do these patterns depend on autotrophic community composition? We estimated internal CO<jats:sub>2</jats:sub> production as the ratio of net ecosystem production to CO<jats:sub>2</jats:sub> water‐to‐air flux (FCO<jats:sub>2</jats:sub>). We also estimated the daily ecosystem quotient (EQ, O<jats:sub>2</jats:sub> released: dissolved inorganic carbon [DIC] consumed) and the prevalence of non‐CO<jats:sub>2</jats:sub> autotrophic DIC uptake pathways under CO<jats:sub>2</jats:sub> depletion. Median internal CO<jats:sub>2</jats:sub> production was 49% of FCO<jats:sub>2</jats:sub> in the Loire from 1990 to 2022. The river predictably shifted from a heterotrophic, CO<jats:sub>2</jats:sub> source to an autotrophic, CO<jats:sub>2</jats:sub> sink as a function of discharge, leading to four trophic‐flux (“trophlux”) states: autotrophic‐sink, autotrophic‐source, heterotrophic‐sink, and heterotrophic‐source. During autotrophic states (41% of the time), CO<jats:sub>2</jats:sub> depletion (FCO<jats:sub>2</jats:sub> ≤ 0, median pCO<jats:sub>2</jats:sub> = 135 <jats:italic>μ</jats:italic>atm) led to the use of and of CO<jats:sub>2</jats:sub> released by CaCO<jats:sub>3</jats:sub> precipitation as alternative DIC sources to autotrophs to support their high rates of primary production (occurring on average for 33% of the growing season). Finally, during a period of phytoplankton dominance, the median EQ was 1.3, which was reduced to 1.0 under macrophyte dominance. This work describes a dynamic coupling among autotrophic communities, calcium carbonate equilibria, and discharge‐controlled FCO<jats:sub>2</jats:sub> that together imply lower‐than‐predicted FCO<jats:sub>2</jats:sub> magnitude and greater‐than‐predicted internal CO<jats:sub>2</jats:sub> production for the Loire River.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"20 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143599354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Relative phase between tidal and solar cycles influences the heating of a coral atoll lagoon","authors":"Sarah Ruth Merrigan, Geno Pawlak, Gregory Sinnett, Ke‐Hsien Fu, Kristen A. Davis","doi":"10.1002/lno.70013","DOIUrl":"https://doi.org/10.1002/lno.70013","url":null,"abstract":"We seek to understand the physical processes driving a recent warming event in Dongsha Atoll lagoon, a coral atoll in the South China Sea. The system has experienced hypoxia‐related fish kills and seagrass die‐offs, further motivating our understanding of circulation and exchange within the lagoon. Hydrographic observations were collected in summer 2019 to examine circulation and ocean–lagoon exchange. A heat budget was constructed to investigate the relative influence of tides, wind, waves, surface heating, and advective ocean–lagoon exchange on the lagoon heat content. Volume fluxes also allow for the estimate of bulk lagoon flushing time, which is critical in driving water temperatures, biogeochemical cycles, and reef ecosystem functions. Over the 22‐d study period, the lagoon warmed by 1.5°C, driven primarily by solar radiative heating. Surface heat fluxes were balanced by cooling from advective exchange through deeper channels and over the shallow reef flat surrounding the lagoon. Without these cooling flows, the lagoon would have heated by 4.5°C over the study period. Estimated flushing times for the Dongsha Atoll lagoon range from 4.6 to 6.1 d for spring and neap tide. A phase‐locked interaction between the diurnal solar cycle and the diurnal tide drives advective cooling over the reef flat into the lagoon at night during the summer, especially during spring tide. These results highlight a unique mechanism shaping seasonal patterns in circulation and heat fluxes in a diurnal‐tide‐dominated reef system, which is likely important for other biogeochemical parameters and in shallow coastal ecosystems with similar tidal forcing.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"54 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143589910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Heatwave intensity drives eco‐physiological responses in infaunal bivalves: A mesocosm experiment","authors":"Maren A. Staniek, Christian Pansch, Lisa N. S. Shama, Knut Mehler, Anna Steinmann, Jack J. Middelburg, Lukas Meysick","doi":"10.1002/lno.70012","DOIUrl":"https://doi.org/10.1002/lno.70012","url":null,"abstract":"Marine heatwaves are increasing globally in intensity and duration. To investigate the potential consequences for coastal ecosystems, the effects of short‐term heat stress must be better understood. This study examined eco‐physiological responses in two common intertidal bivalves, <jats:italic>Cerastoderma edule</jats:italic> and <jats:italic>Macoma balthica</jats:italic>, to different heatwave intensities in a mesocosm experiment under near‐natural environmental conditions. Single‐species assemblages were exposed to a 15‐d heatwave of either +2.8°C (mild heatwave) or +4.4°C (strong heatwave) above ambient temperatures. Survival and condition were monitored, and filtration rates were measured before and during heatwave exposure to investigate feeding behavior. Bivalve respiration rates were measured before, during, and after heatwave exposure as a proxy for metabolic responses. For <jats:italic>C. edule</jats:italic>, we found significantly elevated filtration rates during the mild but not the strong heatwave. For <jats:italic>M. balthica</jats:italic>, survival was similar across treatments, but marine heatwaves had a significant effect on the condition index (tissue/shell mass ratio). During heatwave exposure, respiration rates were similar across treatments for both species. However, following the heatwaves, bivalves previously exposed to a strong heatwave showed lower respiration rates compared to those exposed to an ambient or a mild heatwave. This study revealed that short‐term heatwaves can have persisting negative effects on bivalve metabolism and that the two species responded differently to the heatwave intensities. Further research is needed on the potential long‐term effects of marine heatwaves on intertidal fauna and their capacity to continue providing crucial ecosystem services.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"84 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143532715","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Red and brown macroalgae in temperate stream food webs: Are we missing an important trophic link?","authors":"Marine Escura, Apostolos‐Manuel Koussoroplis, Christian Desvilettes","doi":"10.1002/lno.70007","DOIUrl":"https://doi.org/10.1002/lno.70007","url":null,"abstract":"In temperate low‐order streams and rivers, the macroinvertebrate community has a key role in the flow of matter and energy. Despite its relative scarcity, in‐stream primary producers have a high functional importance for the macroinvertebrates as the main source of Long‐Chained PolyUnsaturated Fatty Acids (LC‐PUFAs), essential biochemical compounds for macroinvertebrates fitness. Among these primary producers, the trophic role of microalgae in periphytic biofilms has been largely studied over the last decades, while macroalgae (Rhodophyta, Ochrophyta) have been neglected or even ignored. We call for future studies quantifying macroalgal species and production in streams, their biochemical composition, as well as their nutritional value for stream invertebrates to assess their potential trophic role in stream food webs. Our literature review indicates that macroalgae can be seasonally and locally abundant in freshwater streams and that they are frequently found in the guts of numerous macroinvertebrate taxa. From a biochemical perspective, the macroalgal species studied are rich in LC‐PUFAs, particularly in Arachidonic Acid (ARA), an omega‐6 fatty acid, contrasting with periphytic biofilms, which are rich in the omega‐3 series, especially Eicosapentaenoic Acid (EPA). Consuming Rhodophyta and Ochrophyta macroalgae as a complementary resource could enable stream invertebrates to optimize their dietary EPA : ARA ratio.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"1 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Issue Information & Members","authors":"","doi":"10.1002/lno.70011","DOIUrl":"https://doi.org/10.1002/lno.70011","url":null,"abstract":"","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 2","pages":"iv"},"PeriodicalIF":3.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70011","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Issue Information & Masthead","authors":"","doi":"10.1002/lno.12802","DOIUrl":"https://doi.org/10.1002/lno.12802","url":null,"abstract":"","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 2","pages":"i"},"PeriodicalIF":3.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.12802","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431246","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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":"Issue Information & TOC","authors":"","doi":"10.1002/lno.70010","DOIUrl":"https://doi.org/10.1002/lno.70010","url":null,"abstract":"","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 2","pages":"iii"},"PeriodicalIF":3.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70010","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143431388","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}