Limnology and Oceanography最新文献

Effect of increased carbon dioxide and iron limitation on coastal and oceanic strains of Synechococcus 二氧化碳增加和铁限制对海岸和海洋聚囊球菌菌株的影响

IF 4.5 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-10 DOI: 10.1002/lno.70130

Huan Wang, William G. Sunda, Haiqi Shen, Haizheng Hong, Dalin Shi

{"title":"Effect of increased carbon dioxide and iron limitation on coastal and oceanic strains of Synechococcus","authors":"Huan Wang, William G. Sunda, Haiqi Shen, Haizheng Hong, Dalin Shi","doi":"10.1002/lno.70130","DOIUrl":"https://doi.org/10.1002/lno.70130","url":null,"abstract":"Iron (Fe) is an essential nutrient that limits primary productivity in vast regions of the oceans. Ongoing increases in ocean carbon dioxide (CO2) concentrations can affect both Fe availability and its requirement by phytoplankton, potentially impacting carbon fixation and the growth of Fe‐limited phytoplankton. The cyanobacterium Synechococcus is one of the most ubiquitous phytoplankton groups in the ocean, and the strategies for oceanic and coastal Synechococcus to cope with low Fe stress may be different owing to large differences in Fe concentrations between oceanic and coastal waters. We cultured the oceanic Synechococcus strain WH8102 and coastal Synechococcus strain WH5701 under different pCO2 levels and concentrations of bioavailable dissolved inorganic iron species (Fe′) to investigate how Fe limitation affects their response to increased CO2 levels. The growth of the coastal strain was more limited by low Fe' concentrations than that of the oceanic strain. High pCO2 significantly promoted the growth rate of both strains only under low Fe' concentrations. At similar degrees of Fe limitation, this effect was larger in the oceanic species and was largely due to a reduced growth demand for Fe‐containing photosynthetic proteins. High pCO2 also down‐regulated CO2‐concentrating mechanisms and reduced intracellular oxidative stress in the Fe‐limited oceanic strain, further benefiting cellular growth rates. Therefore, ongoing and future increases in CO2 concentrations may affect the growth rate and species composition of Synechococcus in Fe‐limited regions of the ocean.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"92 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144603686","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}

引用次数: 0

Radium isotopes quantify vertical mixing and reveal large benthic silicate fluxes in anoxic deep waters 镭同位素量化垂直混合并揭示缺氧深水中大量底栖硅酸盐通量

IF 4.5 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-07 DOI: 10.1002/lno.70126

Tristan McKenzie, Aprajita Singh Tomer, Tibaud Cardis, Claudia Majtényi‐Hill, Beata Szymczycha, Per O. J. Hall, Shibin Zhao, Stefano Bonaglia, Michael Ernst Böttcher, Isaac R. Santos

{"title":"Radium isotopes quantify vertical mixing and reveal large benthic silicate fluxes in anoxic deep waters","authors":"Tristan McKenzie, Aprajita Singh Tomer, Tibaud Cardis, Claudia Majtényi‐Hill, Beata Szymczycha, Per O. J. Hall, Shibin Zhao, Stefano Bonaglia, Michael Ernst Böttcher, Isaac R. Santos","doi":"10.1002/lno.70126","DOIUrl":"https://doi.org/10.1002/lno.70126","url":null,"abstract":"Benthic fluxes are important sources of nutrients and dissolved carbon to the water column. Yet, most approaches for quantifying benthic fluxes are labor intensive and cover relatively small areas of the ocean. Here, we use 224Ra to quantify ecosystem‐scale vertical mixing across a largely hypoxic deep water column in the Baltic Sea and related benthic Si fluxes. Bottom water profiles from 50 stations along a ~ 5000 km cruise track in the Baltic Sea revealed highest 224Ra activities in the deep anoxic basins near the sediment source. Dissolved Si concentrations reached 110 μM and followed a similar trend to radium. For the radium‐based vertical mixing model, 26 out of 50 stations satisfied the required assumptions. When criteria were met, the radium profiles resolved vertical mixing rates on the order of 10−4 m2 s−1 and median dissolved Si fluxes of 5.9 mmol m−2 day−1, both well within the range of previous local scale estimates based on modeling and sediment core incubations. Extrapolated benthic dissolved Si fluxes were 32 times greater than river dissolved Si flux to the Baltic Sea, highlighting the large contribution of seafloor sources to the water column.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"20 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144568608","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}

引用次数: 0

Climate‐driven alterations of lake thermal regimes 气候驱动的湖泊热状态变化

IF 4.5 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-07 DOI: 10.1002/lno.70128

Christopher J. Sullivan, Jordan S. Read, Gretchen J. A. Hansen

{"title":"Climate‐driven alterations of lake thermal regimes","authors":"Christopher J. Sullivan, Jordan S. Read, Gretchen J. A. Hansen","doi":"10.1002/lno.70128","DOIUrl":"https://doi.org/10.1002/lno.70128","url":null,"abstract":"Temperate lakes are undergoing climate‐driven alterations in their thermal regimes, changing their ecology. Previous efforts to understand temperature changes have overlooked multi‐dimensional temperature dynamics, missing complex shifts at high spatiotemporal resolutions across landscapes. Here, we use simulated daily water temperature profiles from > 11,000 temperate lakes throughout the Midwestern United States to (1) quantify multivariate, landscape‐scale patterns in contemporary thermal regimes and (2) contextualize forecasted shifts and identify novel regimes that may emerge with climatic change. Hierarchical clustering and principal component analyses identified six lake clusters with distinct thermal regimes driven by differences in annual warming rates and spring–summer dynamics, with secondary influences from extreme heat events and seasonal variability. Annual temperature variations were influenced by lake‐specific physical characteristics, emphasizing distinct thermal profiles and seasonal variability patterns. Projected climate‐driven alterations in thermal regimes suggest a homogenization toward warmer and more variable conditions, with the majority of lakes characterized by higher temperatures and increased variability. Few lakes (n = 310), particularly in the southern and southeastern Midwest, may experience novel, non‐analog conditions by the late 21st century, while others will undergo shifts between clusters but remain within analogous regime frameworks. Projected changes in lake thermal regimes highlight concerns about ecological impacts on aquatic species and habitats, especially as extreme and variable growing season temperatures intensify and periods of stratification become prolonged. Furthermore, we identify thermal regimes that are likely to dominate the region by the late 21st century while identifying those likely to be lost. The ecological consequences of such changes remain unknown.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"37 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144577698","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}

引用次数: 0

Predictive links between microbial communities and biological oxygen utilization in the Arctic Ocean 北冰洋微生物群落与生物氧利用之间的预测联系

IF 4.5 1区地球科学

Limnology and Oceanography Pub Date : 2025-07-03 DOI: 10.1002/lno.70125

Emelia J. Chamberlain, Sebastian Rokitta, Björn Rost, Alessandra D'Angelo, Jessie M. Creamean, Brice Loose, Adam Ulfsbo, Allison A. Fong, Clara J. M. Hoppe, Elise S. Droste, Daiki Nomura, Kirstin Schulz, Jeff Bowman

{"title":"Predictive links between microbial communities and biological oxygen utilization in the Arctic Ocean","authors":"Emelia J. Chamberlain, Sebastian Rokitta, Björn Rost, Alessandra D'Angelo, Jessie M. Creamean, Brice Loose, Adam Ulfsbo, Allison A. Fong, Clara J. M. Hoppe, Elise S. Droste, Daiki Nomura, Kirstin Schulz, Jeff Bowman","doi":"10.1002/lno.70125","DOIUrl":"https://doi.org/10.1002/lno.70125","url":null,"abstract":"Microbial metabolism influences rates of net community production (NCP), exerting a direct biological control on marine oxygen and carbon fluxes. In the Arctic, it is increasingly important to understand and quantify this process, as ecological and oceanographic conditions shift due to changing climate. Here, we describe potential ecological links between pelagic microbial diversity and an NCP precursor, biological oxygen utilization, using machine learning and paired observations of community structure and metabolic activity from a seasonally and spatially variable transect of the Arctic Ocean (2019–2020 MOSAiC Expedition). Community structure was determined using 16S (prokaryotic) and 18S (eukaryotic) rRNA gene amplicon sequencing, and metabolic activity was derived from ΔO2/Ar. Using self‐organizing maps, we identified clear successional patterns in observed microbial community structure that were seasonally driven in the upper ocean and vertically stratified with depth. Metabolic activity was also stratified, with a primarily net heterotrophic water column (median −1.5% biological oxygen saturation), excepting periodic oxygen supersaturation (maximum: 13.6%) within the mixed layer. Using DNA sequences as predictor variables, we then constructed a random forest regression model that reliably reconstructed biological oxygen concentrations (root mean squared error = 4.14 μmol kg−1). Top predictors from this model were from heterotrophic (bacteria) or potentially mixotrophic (dinoflagellate) taxa. These analyses highlight biologically driven diagnostic tools that can be used to expand biogeochemical datasets and improve the microbial perspectives and metabolisms represented in ecological models of net productivity and carbon flux in a changing Arctic Ocean.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"1 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144566210","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}

引用次数: 0

Prairie stream nutrient stoichiometry across space and time: Influence of discharge, season, and crop type 跨时空的草原河流养分化学计量：流量、季节和作物类型的影响

IF 4.5 1区地球科学

Limnology and Oceanography Pub Date : 2025-06-30 DOI: 10.1002/lno.70117

Amy B. White, Robert B. Brua, Kristin J. Painter, Helen P. Jarvie, Adam G. Yates

{"title":"Prairie stream nutrient stoichiometry across space and time: Influence of discharge, season, and crop type","authors":"Amy B. White, Robert B. Brua, Kristin J. Painter, Helen P. Jarvie, Adam G. Yates","doi":"10.1002/lno.70117","DOIUrl":"https://doi.org/10.1002/lno.70117","url":null,"abstract":"Stream water nutrient ratios are often influenced by flow variation and landscape characteristics. However, the influence of these drivers on total and dissolved nutrient ratios remains understudied, especially in prairie ecosystems where hydrologic connectivity between soils and streams exhibits substantial spatial and seasonal variability. Here, we ask how hydrology and land cover drive patterns of nitrogen (N), phosphorus (P), and N : P ratios across streams and rivers draining northern prairie ecosystems. To answer this, we compiled nutrient concentration data for tributaries of the Red River, Manitoba, Canada, to assess seasonal and annual variation in nutrient ratios, as well as the relationship between crop cover, discharge, and ratios, over 1‐yr, 10‐yr, and 30‐yr time spans. Total nitrogen : total phosphorus ratios were near the Redfield mass ratio (N/P = 7.23) across 24 streams in the Red River Valley. By comparison, dissolved inorganic nitrogen : total dissolved phosphorus ratios in these streams were N depleted and generally declined from spring through to autumn. The types of crops grown did not appear to be a consistent influence on nutrient ratios in streams throughout the region. In contrast, stream flows strongly influenced spring and summer nutrient ratios in four tributaries over a 30‐yr period. Specifically, increasing stream flow tended to decrease TN : TP and DIN : TDP in the two eastern tributaries but increase DIN : TDP in the western tributaries. Our findings that nutrient ratios in prairie streams are impacted by seasonality and fluctuating hydrologic conditions suggest that nutrient ratios in Red River tributaries may be impacted by future climate change.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"30 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144520501","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}

引用次数: 0

Issue Information & TOC 发行信息和TOC

IF 3.8 1区地球科学

Limnology and Oceanography Pub Date : 2025-06-28 DOI: 10.1002/lno.70113

引用次数: 0

Issue Information & Masthead 发行信息和报头

IF 3.8 1区地球科学

Limnology and Oceanography Pub Date : 2025-06-28 DOI: 10.1002/lno.70115

引用次数: 0

Issue Information & Copyright 发行信息及版权

IF 3.8 1区地球科学

Limnology and Oceanography Pub Date : 2025-06-28 DOI: 10.1002/lno.70114

引用次数: 0

Issue Information & Members form 发行信息和会员表格

IF 3.8 1区地球科学

Limnology and Oceanography Pub Date : 2025-06-28 DOI: 10.1002/lno.70116

引用次数: 0

On the fundamental additive modes of ocean color absorption 海洋颜色吸收的基本加性模式

IF 4.5 1区地球科学

Limnology and Oceanography Pub Date : 2025-06-28 DOI: 10.1002/lno.70098

J. Xavier Prochaska, Patrick Gray

{"title":"On the fundamental additive modes of ocean color absorption","authors":"J. Xavier Prochaska, Patrick Gray","doi":"10.1002/lno.70098","DOIUrl":"https://doi.org/10.1002/lno.70098","url":null,"abstract":"Previous principal component analyses of ocean color absorption coefficient spectra have shown the variation in these data is captured by a few eigenfunctions. Here, we perform an unsupervised, non‐negative matrix factorization (NMF) of to derive their fundamental and physically interpretable modes. When applied independently to two large datasets—one semi‐empirical and one from inline measurements of the Tara Microbiome expedition—we find that four NMF basis functions describe of the variance in each. Furthermore, despite significant differences between the datasets in methodology and by geographic and temporal acquisition, the two sets of basis functions show very similar features at wavelengths nm. Two of the modes capture the amplitude and spectral slope of absorption by color dissolved organic matter and/or detritus. The other two describe absorption by phytoplankton () separated into the pigments that couple tightly to the chlorophyll a (Chl a) 675 nm feature and another that captures variability at nm. Together, the majority of ocean color absorption is physically described by these four fundamental modes. We present several applications of the NMF analysis including the exploration of geographic trends in particulate composition, the search for outlier absorption spectra, and the application of a new, additive decomposition of . Lastly, we detail the limitations of this technique, especially in the context of mechanistic approaches more commonly adopted in the literature.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"22 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144503617","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}

引用次数: 0