Limnology and Oceanography最新文献

{"title":"Seasonal genotypic and phenotypic differentiation of a cosmopolitan freshwater diatom","authors":"Domiziana Cristini, Joseph B. Kelly, Pia Mahler, David Schleheck, Harry Lerner, Lutz Becks","doi":"10.1002/lno.70207","DOIUrl":"https://doi.org/10.1002/lno.70207","url":null,"abstract":"Most ecosystems are characterized by seasonality, which, through biotic and abiotic changes, influences species biomass dynamics. Recent studies have shown that ecologically important traits can evolve rapidly in response to environmental changes, resulting in eco‐evolutionary dynamics with consequences for population and community dynamics. Evidence for seasonal effects on intraspecific variation is still scarce and understanding eco‐evolutionary dynamics in the presence of seasonal fluctuations remains a major challenge. Following the phytoplankton spring bloom in Lake Constance, we investigated how seasonal changes influence the intraspecific diversity of <jats:italic>Asterionella formosa</jats:italic> both at genotypic and phenotypic levels. We found a moderate degree of genetic and phenotypic differentiation characterizing the <jats:italic>Asterionella</jats:italic> population, explained by a clustering of the isolates into early and late spring according to lake thermal stratification. Yet, most traits related to environmental parameters as well as fitness in different seasonal environments did not show a clear response to seasonality (i.e., temperature and nutrients). The changes in genetic patterns observed after a peak in parasite relative abundance suggested that seasonal changes in biotic interactions (i.e., parasitic chytrids) might be an important driver of the observed seasonal shift in <jats:italic>Asterionella</jats:italic> genotypes. Our results highlight the importance of studying eco‐evolutionary processes for understanding variations in population and community dynamics in response to seasonal environmental fluctuations.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"4 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145084288","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":"Ecophysiology of two mesophotic octocorals intended for restoration: Effects of light and temperature","authors":"Kassidy Lange, Allisan Aquilina‐Beck, Mark McCauley, Julia Johnstone, Amanda Demopoulos, Thomas Greig, Jody M. Beers, Heather L. Spalding, Peter J. Etnoyer","doi":"10.1002/lno.70214","DOIUrl":"https://doi.org/10.1002/lno.70214","url":null,"abstract":"Light and temperature are driving forces that shape the evolution and physiology of mesophotic organisms. On the Mississippi‐Alabama continental shelf, octocorals dominate the mesophotic seascape and provide habitat for many fish and invertebrate species. Gaps in knowledge regarding the fundamental physiological responses of these species to light and temperature are of particular interest to restoration activities following the <jats:italic>Deepwater Horizon</jats:italic> oil spill. To address these gaps, the photobiology and thermal tolerance of <jats:italic>Swiftia exserta</jats:italic> and <jats:italic>Muricea pendula</jats:italic> were assessed in the field and laboratory. Pulse amplitude modulated fluorometry, histology, light microscopy, and epifluorescence imaging revealed low densities of photosynthetic endobionts in samples of <jats:italic>S. exserta</jats:italic> and none in samples of <jats:italic>M. pendula</jats:italic> collected near the determined bottom of the euphotic zone (51.45 m). Response to the recorded monthly mean habitat temperature range (18.5–25.4°C) was assessed using respirometry and polyp activity data from live corals exposed to temperatures between 18°C and 26°C. There was no significant difference in oxygen consumption for either species between 18°C and 26°C, and calculated <jats:italic>Q</jats:italic><jats:sub>10</jats:sub> values were not significantly different from 1, thus suggesting that both species have a low sensitivity to the local thermal environment. However, a negative correlation between temperature and polyp activity suggests that <jats:italic>M. pendula</jats:italic> is more sensitive to higher temperatures than <jats:italic>S. exserta</jats:italic>. This study improves the understanding of the effects of light and temperature on mesophotic octocoral physiology and lays the foundation for future work to explore the thermal thresholds of each species and the endobiont–host relationship in <jats:italic>S. exserta</jats:italic>.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"35 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145077659","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":"Sediment depth–dependent fungal community and biogeochemical potentials along the abyssal–hadal transition zone of the Mariana Trench","authors":"Qianqian Song, Qun Jiang, Hongmei Jing, Xiang Xiao, Zhiyong Li","doi":"10.1002/lno.70212","DOIUrl":"https://doi.org/10.1002/lno.70212","url":null,"abstract":"The Mariana Trench is the deepest of the world's deep‐sea trenches. To date, our knowledge of the fungal metabolism and biogeochemical cycles in the Mariana Trench biosphere is very limited compared with the Mariana Trench prokaryotes. Here, we collected the sediment cores from three layers (surficial 0–6 cm, intermediate 6–12 cm, and deep 12–18 cm) at eight stations in the abyssal–hadal transition zone of the Mariana Trench to investigate the sediment fungal community and biogeochemical potentials using metagenomics. Eight fungal phyla were detected, with Ascomycota being the most abundant, followed by Mucoromycota and Basidiomycota, along with the unique representatives Microsporidia and Rozellomycota (Cryptomycota). Distinct fungal community and biogeochemical potentials of carbon, sulfur, and nitrogen in the fine scale of the different sediment layers were revealed, while no obvious difference was detected between the southern and northern slopes of the abyssal–hadal transition zone of the Mariana Trench. In particular, the assimilatory sulfate reduction (ASR) pathway, including <jats:italic>sat</jats:italic> and <jats:italic>cysI</jats:italic>, <jats:italic>cysC/PAPSS</jats:italic> catalytic processes, as well as the dissimilatory nitrite reduction to ammonia by <jats:italic>NIT‐6</jats:italic>, were highlighted based on the fungal metagenome. These results suggest sediment depth–dependent fungal community and biogeochemical potentials, providing novel insights into the less well‐known fungal microbiome in the Mariana Trench, particularly fungal different pathways from prokaryotes.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"19 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145077657","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":"Climate warming disrupts zooplankton phenology and overwintering strategies","authors":"Ida K. Svendsen, Anders Forsman, Mark Dopson, Emelie Nilsson, Johanna Sunde, Sofia Håkansson, Marcelo Ketzer, Samuel Hylander, Romana K. Salis","doi":"10.1002/lno.70162","DOIUrl":"https://doi.org/10.1002/lno.70162","url":null,"abstract":"Zooplankton are crucial for food webs and biogeochemical cycles. However, warming associated with climate change may alter their seasonal timing and reproductive strategies. This study investigated how long‐term warming impacted zooplankton (mainly copepods) phenology and overwintering strategies by comparing a Baltic Sea bay, heated by warm water discharge for more than 50 yr, with an unaffected control bay. Field observations showed that copepod and phytoplankton population growth began earlier in the heated bay than in the control bay, suggesting that copepod abundance was driven by both temperature and food availability in the heated bay and by a stronger temperature dependence in the control bay. Resting eggs are normally produced as a life‐history strategy to survive unfavorable environmental conditions. Our laboratory incubation experiment showed fewer dormant resting eggs hatched from the heated bay sediment compared with the control bay, supporting an evolutionary change in overwintering strategy. In conclusion, the results seemed to suggest that copepods adjusted their life‐history in elevated temperatures by relying less on the strategy of using sediment‐stored dormant eggs and instead started their spring development earlier, when phytoplankton food was available. Hence, this study suggests that climate change can shift copepod overwintering strategies, leading to potential cascading effects in the food web and affecting overall biodiversity and productivity.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"307-308 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-09-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072178","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":"Daily temperature variation explains zooplankton community differences in freshwater mesocosms recovering from a natural drought","authors":"James R. Hubbard, Dania Albini, Michelle C. Jackson","doi":"10.1002/lno.70181","DOIUrl":"https://doi.org/10.1002/lno.70181","url":null,"abstract":"Drought events are typically studied as a single stressor. However, multiple environmental variables are altered under drought conditions, including water level and daily temperature variation. Here, we experimentally manipulated both variables in 16 outdoor mesocosms to disentangle how they impact freshwater zooplankton communities. During a natural drought in summer 2022, we maintained water level in eight mesocosms while allowing eight to almost dry out. We reduced daily temperature variation using insulation in half of these outdoor mesocosms to give a fully factorial design with four replicates for each of the four treatments: <jats:italic>Control</jats:italic>, <jats:italic>Low water level</jats:italic>, <jats:italic>Insulated</jats:italic>, <jats:italic>Insulated</jats:italic> + <jats:italic>Low water level</jats:italic>. We found a lasting effect of low water level over the 150‐day study period; community recovery was incomplete despite natural precipitation restoring the <jats:italic>Low water level</jats:italic> treatment to a similar depth as <jats:italic>Controls</jats:italic>. However, our results consistently identified daily temperature variation as more important than water depth in explaining drought effects, with amplified daily temperature variation strongly associated with the initial divergence of zooplankton community structure and reductions in net biomass. Since daily temperature variation may be higher in small outdoor mesocosms than larger natural freshwaters, we recommend that this is considered in the design of mesocosm experiments. By taking a multiple stressor perspective, our findings indicate that temperature variation can be more important than water level in structuring freshwater invertebrate communities.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"36 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072181","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":"High‐resolution coral oxygen and carbon isotope records reveal temperature and autotrophy dynamics in a Mediterranean climate change hotspot","authors":"Diego K. Kersting, Thomas C. Brachert, Juan P. D'Olivo, Cristina Linares, Lars Reuning, Joan Lluís Riera, Philipp Spreter, Ulrich Struck, Marina J. Vergotti, Jens Zinke","doi":"10.1002/lno.70208","DOIUrl":"https://doi.org/10.1002/lno.70208","url":null,"abstract":"The Mediterranean Sea is warming at a rate exceeding the global average. Long‐term, high‐resolution data are essential for contextualizing changes within broader temporal scales, and coral skeletons provide valuable environmental archives, especially in data‐sparse regions or as supplements to existing records. While coral‐based reconstructions are well established in tropical settings, they remain limited in temperate areas. As the only reef‐building zooxanthellate coral in the Mediterranean, <jats:italic>Cladocora caespitosa</jats:italic> is particularly important for expanding coral‐based environmental archives in these understudied regions. Here, we present records of δ<jats:sup>18</jats:sup>O and δ<jats:sup>13</jats:sup>C in the skeletons of <jats:italic>C. caespitosa</jats:italic> from a global change sentinel site in NW Mediterranean. This study provides the most accurate temperature–δ<jats:sup>18</jats:sup>O calibration equations for <jats:italic>C. caespitosa</jats:italic>, including a traditional linear model and a novel exponential model that better accounts for the region's wide seasonal temperature range. Both calibrations rely on long‐term in situ water temperature data and a multi‐corallite composite approach to reduce non‐climatic variability. Seasonal trends in δ<jats:sup>13</jats:sup>C reveal, for the first time, variation in the coral's autotrophy–heterotrophy balance, while geochemical anomalies in the skeletons signal thermal stress effects on biomineralization. Our findings establish <jats:italic>C. caespitosa</jats:italic> skeletons as critical archives for reconstructing anthropogenic warming and its ecological effects in the Mediterranean.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"74 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072421","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":"Aquatic fungal diversity assessment through metagenomics is still limited to current databases","authors":"Anushree Sanyal, Mariana Kluge, Miguel Angel Redondo, Moritz Buck, Maliheh Mehrshad, Sarahi L. Garcia, Stefan Bertilsson, Sari Peura","doi":"10.1002/lno.70205","DOIUrl":"https://doi.org/10.1002/lno.70205","url":null,"abstract":"Fungi play essential roles across ecosystems, yet their diversity in aquatic environments remains poorly understood compared to terrestrial systems. To address this gap, we analyzed metagenomes from 26 lakes in the boreal and subarctic zones, along with one tropical reservoir, to characterize fungal and fungal‐like (Oomycota) community structure. We also examined environmental factors shaping these communities. Most variation in fungal composition was explained by lake identity, depth layer, and season, with total organic carbon as a significant explanatory variable. Despite geographic and time differences, dominant fungal phyla, orders, and genera were largely consistent across all lakes. However, genus‐level variation indicated distinct community compositions likely influenced by differences in carbon substrate availability. Attempts to classify metagenomic reads down to the species level—illustrated here through the well‐characterized oomycete genus <jats:italic>Phytophthora</jats:italic>—were constrained by the limited taxonomic resolution of current reference databases. While metagenomics offers powerful means to investigate entire microbial communities, our results underscore a persistent bottleneck: the insufficient representation of aquatic eukaryotic genomes in public databases.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"9 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-09-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145072180","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":"Urban heterogeneity drives dissolved organic matter sources, transport, and transformation from local to macro scales","authors":"Rebecca L. Hale, Kristina G. Hopkins, Krista A. Capps, John S. Kominoski, Jennifer L. Morse, Allison H. Roy, Shuo Chen, Annika Quick, Andrew J. Blinn, Liz Ortiz Muñoz, Gwendolynn Folk","doi":"10.1002/lno.70201","DOIUrl":"https://doi.org/10.1002/lno.70201","url":null,"abstract":"Urbanization reshapes dissolved organic matter (DOM) sources, transport, and transformations through changes in vegetation, hydrology, and management of waste and water. Yet the impacts of urbanization on DOM are variable within and among cities. Predicting heterogeneous responses to urbanization is challenged by diverse human activities and underlying biophysical variation along stream networks. Using data from the 486 largest urban areas in the continental United States and seven focal cities, we identified macro and local scale urban gradients in social, built, and biophysical factors that are expected to shape DOM. We used these gradients and the literature to develop hypotheses about heterogeneity in DOM quantity and quality within and among cities. Interactions among landscape and infrastructure attributes across spatial and temporal scales result in heterogeneous responses in DOM. Characterizing and quantifying these inconsistent responses to urbanization in contrasting settings may help to better understand heterogeneity and identify generalities among urban watersheds.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"14 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145035529","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":"Under which conditions can tidal reeds contribute to shore protection? The critical interplay between external stress and internal stress resistance in brackish marshes","authors":"Jana Carus, Dörthe Holthusen, Tim Scheufen, Heiner Fleige, Hamed Kashi, Maike Heuner","doi":"10.1002/lno.70184","DOIUrl":"https://doi.org/10.1002/lno.70184","url":null,"abstract":"Tidal reeds provide essential coastal protection by shielding the shore from the effects of waves and currents, reducing soil erosion or even enabling sediment accretion. However, these environments face increasing threats from human activities and climate change. This study focuses on the Elbe estuary in Germany, investigating factors that influence tidal reed expansion and recession. We investigated the dynamics of three shore sections, comparing reed‐dominated and grassland‐dominated shore sections, and assessed their ability to attenuate waves and mitigate shoreline erosion. Our findings reveal significant differences in shoreline dynamics between the sites, influenced by factors such as hydrodynamic stress, vegetation cover, and sediment composition. In particular, we highlight how tidal reeds contribute to shore stabilization through wave attenuation and the strengthening effects of their root systems during periods of reduced plant biomass in winter. However, the effectiveness of reeds in shoreline protection depends on the level of external stress, particularly from storm surges, with areas exposed to higher hydrodynamic forces showing greater erosion. The study underscores the importance of maintaining tidal reeds for resilient coastal protection, while also acknowledging that external stress factors sometimes require supplementary measures to ensure long‐term shoreline stability. Our results contribute to a deeper understanding of estuarine shore dynamics and offer insights for future management strategies.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"38 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-09-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145035530","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":"Broad‐scale climate patterns combined with local flow and turbidity disturbances structure the seasonality of gross primary production in an aridland river","authors":"Betsy M. Summers, Robert O. Hall, Justin K. Reale, Eric Joseph, Mark C. Stone, David J. Van Horn","doi":"10.1002/lno.70173","DOIUrl":"https://doi.org/10.1002/lno.70173","url":null,"abstract":"Both local and global climate phenomena shape the hydrologic regimes of watersheds. For aridland rivers in the southwestern United States, peak flows occur during two distinct periods: spring snowmelt and summer monsoons. Although discharge (<jats:italic>Q</jats:italic>) is a primary driver of variation in the production and consumption of instream organic matter, or stream metabolism, few connection have been made regarding how climate impacts ecosystem processes through changes in flow and related disturbances. We considered how variation in disturbance variables, specifically <jats:italic>Q</jats:italic> and associated changes in turbidity, affected gross primary production during spring snowmelt and summer monsoons in the Rio Grande. Nine years of continuous environmental data (<jats:italic>Q</jats:italic>, turbidity, light) and climate indices (i.e., El Niño‐Southern Oscillation and Monsoon Index) were used to explain the variation in gross primary production estimates. We found that relationships were sensitive to the timescale of disturbance: at the seasonal scale, high snowmelt <jats:italic>Q</jats:italic> decreased spring mean gross primary production, while at the daily scale, high turbidity, and to a lesser extent <jats:italic>Q</jats:italic>, reduced gross primary production during summer. Also, mean <jats:italic>Q</jats:italic> and turbidity disturbances were uncoupled in spring and inversely related in summer. We conclude that long‐term datasets are essential to uncover emergent relationships between broad‐scale climate patterns and ecosystem processes and are necessary to better understand how hydroclimatic variability drives ecosystem processes at varying time scales in rivers across Earth.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"16 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145003178","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}