Limnology and Oceanography最新文献

{"title":"Global satellite observations of marine phytoplankton pigments over the past two decades","authors":"Deyong Sun, Yuhang Chen, Zhenghao Li, Shengqiang Wang, Peng Chen, Yu Huan","doi":"10.1002/lno.70017","DOIUrl":"https://doi.org/10.1002/lno.70017","url":null,"abstract":"Documenting the variations of phytoplankton pigments is essential for understanding phytoplankton assemblages' dynamics and physiological characteristics in the global oceans. Advanced chlorophyll <jats:italic>a</jats:italic> satellite product has provided an overview of global phytoplankton biomass, yet deeper taxonomic biomass monitoring demands more detailed pigment information. In this study, we have collected 1562 in situ measured sea surface samples (depth &lt; 10 m) from 1997 to 2017 covering the global ocean, where the in situ dataset consists of pigment concentration and phytoplankton absorption coefficient (<jats:italic>a</jats:italic><jats:sub>ph</jats:sub>). A global semi‐analytical pigment model was developed using the Gaussian decomposition method and was evaluated by the leave‐one‐out cross validation method. Model accuracy verification based on in situ measurement (e.g., mean absolute percentage errors below ~ 67% for most pigments) and satellite synchronization dataset (e.g., most pigments have mean absolute percentage errors below ~ 70%) showed the reliable performance of the pigment model in the global oceans. We reconstructed the global hyperspectral phytoplankton absorption by the three‐component absorption model of the phytoplankton size class, enabling satellite application of the pigment model and obtaining the nearly 20‐yr spatiotemporal variations of 14 phytoplankton pigments. Global pigment concentrations exhibited a generally relatively unchanging pattern at the beginning of the 21<jats:sup>st</jats:sup> century, as evidenced by stable geographic distribution and temporal trends, while local environmental disturbances created anomalies in 1‐yr period. Our findings provide an effective model to detect global pigment concentration and essential satellite products for further analysis of phytoplankton assemblages.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"16 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143608179","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":"Algal food identity affects morphological anti‐predatory defense in Daphnia pulex","authors":"Carlos Sánchez Arcos, Yannick Hill, Sandra Klintworth, Eric von Elert","doi":"10.1002/lno.70018","DOIUrl":"https://doi.org/10.1002/lno.70018","url":null,"abstract":"Microcrustaceans of the genus <jats:italic>Daphnia</jats:italic> have evolved various inducible anti‐predator defenses; however, it is largely underexplored how the bottom‐up factor food quality may affect the extent of these defenses. A well‐studied example of an inducible defense is the deployment of neckteeth in <jats:italic>Daphnia pulex</jats:italic> in response to infochemicals from predatory larvae of <jats:italic>Chaoborus</jats:italic>, which prey on juvenile instars of <jats:italic>Daphnia</jats:italic>. In general, vulnerability depends on the body size in the respective juvenile <jats:italic>Daphnia</jats:italic> instars in relation to the mouth gape diameter of <jats:italic>Chaoborus</jats:italic> larvae. We hypothesized that algae that prolong the time in which juvenile animals remain in the vulnerable size also increase the predation risk and therefore increase the extent of induced neckteeth. To test this, we supplied three <jats:italic>D. pulex</jats:italic> genotypes with three food algae and quantified somatic growth rates, time in vulnerable instars, and neckteeth in response to <jats:italic>Chaoborus</jats:italic> infochemicals. Food algal identity affected the extent of induced neckteeth by up to 66%. However, this effect was not positively related to the time spent in vulnerable instars, indicating that the time that juveniles remain in a vulnerable size is not used to assess predation risk. We demonstrate that food identity may significantly affect the extent of induced neckteeth in <jats:italic>D. pulex</jats:italic> in a genotype‐dependent way. This strongly suggests that in nature, changing phytoplankton composition may affect the degree of morphological defense and thus constitutes a bottom‐up control of chemical predator–prey communication. This is another example of how environmental factors modulate the temporal dynamics of phenotypic plasticity.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"11 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143599350","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":"Multi‐trait responses in two marine diatoms to pH and irradiance reveal interactive effect of light and acidification, mediated by silicification","authors":"Billy FitzGerald‐Lowry, Daniel Aagren Nielsen, Rebecca Julianne Duncan, Alyson May Theseira, Georgia Thompson, Katherina Petrou","doi":"10.1002/lno.70014","DOIUrl":"https://doi.org/10.1002/lno.70014","url":null,"abstract":"Ocean ecosystem shifts in response to anthropogenic climate change are impacting marine organisms, including phytoplankton. Ocean acidification and warming represent two key threats to marine phytoplankton, causing significant changes to the upper mixed layer of the ocean, reshuffling their distribution, and reorganizing their physiology and metabolism. In this study, we investigated changes in biomolecular composition and silicification rates of the two “model” diatom species <jats:italic>Phaeodactylum tricornutum</jats:italic> and <jats:italic>Thalassiosira weissflogii</jats:italic> under low (~ 350) and projected future (~ 800) <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> concentrations with low (20 <jats:italic>μ</jats:italic>mol photons m<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup>) and high (200 <jats:italic>μ</jats:italic>mol photons m<jats:sup>−2</jats:sup> s<jats:sup>−1</jats:sup>) light, simulating expected climate change‐induced impacts of ocean shoaling and acidification. Specifically, our study conditions elicited changes in lipid and protein content in both species. We also found a negative effect of <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> on silica production under high light in <jats:italic>T. weissflogii</jats:italic> that was linked to improved photochemical efficiency. This interactive effect between light and <jats:italic>p</jats:italic>CO<jats:sub>2</jats:sub> with silica production suggests a potential controlling role of the frustule in diatom photosynthesis and photoprotection (energy balance). Based on these data, ocean shoaling and acidification have the potential to influence the nutritional value and biogeochemical role of diatoms through its effect on diatom frustule synthesis and photobiology.","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"86 1","pages":""},"PeriodicalIF":4.5,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143599352","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":"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":"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":"Macroalgae detritus decomposition and cross-shelf carbon export from shallow and deep reefs","authors":"Taylor Simpkins,&nbsp;Mirjam Van Der Mheen,&nbsp;Morten F. Pedersen,&nbsp;Albert Pessarrodona,&nbsp;Chari Pattiaratchi,&nbsp;Thomas Wernberg,&nbsp;Karen Filbee-Dexter","doi":"10.1002/lno.70006","DOIUrl":"10.1002/lno.70006","url":null,"abstract":"<p>Macroalgal forests have been suggested to export substantial amounts of carbon to deep ocean sinks and could account for 27–34% of annual blue carbon sequestered in Australia. However, a major knowledge gap concerns how carbon in the detrital tissue of the dominant seaweed species is remineralized as it is exported offshore. We quantified decomposition and carbon content in detrital tissue of dominant canopy-forming seaweeds <i>Ecklonia radiata</i> and <i>Scytothalia dorycarpa</i> at three depths (10, 20, and 50 m) in a 50 d in situ litterbag experiment in Western Australia. We then combined these rates with a particle tracking model to estimate the potential export of macroalgae detritus from our experiment sites into deeper waters. Decomposition of particulate organic carbon was fast relative to other cooler regions globally, and there were no significant differences between species and most depths. One-half of the detritus was remineralized within 12 (± 2) days for <i>E. radiata</i> and 8 (± 2) days for <i>S. dorycarpa</i>, with ~ 8% remaining for both species after 50 d in situ. Based on simulated transport times and decomposition, 10% and 11% of the <i>E. radiata</i> and <i>S. dorycarpa</i> detritus from shallow reefs (10–20 m) were exported beyond the shelf break (≥ 200 m) whereas 47% and 37% were exported from deep reefs (50 m). These estimates highlight the variable but substantial carbon sequestration potential across the coastal zone.</p>","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 4","pages":"1046-1058"},"PeriodicalIF":3.8,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1002/lno.70006","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143599353","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":"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,&nbsp;Apostolos-Manuel Koussoroplis,&nbsp;Christian Desvilettes","doi":"10.1002/lno.70007","DOIUrl":"10.1002/lno.70007","url":null,"abstract":"<p>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.</p>","PeriodicalId":18143,"journal":{"name":"Limnology and Oceanography","volume":"70 4","pages":"1059-1074"},"PeriodicalIF":3.8,"publicationDate":"2025-02-27","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}