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Seasonal patterns of phytoplankton photoacclimation in a dimictic oligotrophic lake over 5 yr: Implications for chlorophyll as an estimate of biomass Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-03-16 Scott Girdner, Joshua Sprague
Chlorophyll a is commonly used as a surrogate for algal biomass in lakes and oceans even though phytoplankton can readily adjust intracellular chlorophyll concentration to changes in the environment through a cellular process termed photoacclimation. Marine studies have documented fluctuations in cellular chlorophyll to year‐round changes in light intensity and nutrients using the chlorophyll : carbon
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Fluorescently labeled prey surrogates in combination with fluorescence‐activated cell sorting successfully discriminate actively feeding mixotrophs in a lake water sample Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-03-14 Javier Florenza, Anna‐Maria Divne, Stefan Bertilsson
Mixotrophic protists are capable of acting both as primary producers and primary consumers at the base of the aquatic food web, thus constituting key organisms in ecosystems where they are abundant. However, their identity, abundance, ecological dynamics, and biogeochemical impact in aquatic ecosystems remain understudied in comparison to classically demarcated autotrophs or heterotrophs. In this study
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Detecting climate‐related shifts in lakes: A review of the use of satellite Earth Observation Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-03-12 Elisa Calamita, J. Jelle Lever, Clement Albergel, R. Iestyn Woolway, Daniel Odermatt
Climate change exerts a profound impact on lakes, eliciting responses that range from gradual to abrupt transitions. When reaching critical tipping points, the established lake dynamics stand to undergo substantial modifications, setting off a chain reaction that reverberates through the entire ecosystem. This lake shift ripples into related ecosystem services and even influences the well‐being of
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Changes in isotope fractionation during nitrate assimilation by marine eukaryotic and prokaryotic algae under different pH and CO2 conditions Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-03-11 Yawen Chen, Jin‐Yu Terence Yang, Jin‐Ming Tang, Haizheng Hong, Shuh‐Ji Kao, Minhan Dai, Dalin Shi
The impact of environmental factors on nitrogen (N) and oxygen (O) isotope effects during algal nitrate assimilation causes uncertainty in the field application of sedimentary N isotope records and nitrate isotopes to understand the marine nitrogen cycle. Ocean acidification is predicted to change nitrogen cycling including nitrate assimilation, but how N and O isotope effects during algal nitrate
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Vertical trophic structure and niche partitioning of gelatinous predators in a pelagic food web: Insights from stable isotopes of siphonophores Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-03-09 Elizabeth D. Hetherington, Hilary G. Close, Steven H. D. Haddock, Alejandro Damian‐Serrano, Casey W. Dunn, Natalie J. Wallsgrove, Shannon C. Doherty, C. Anela Choy
Gelatinous zooplankton are increasingly recognized as key components of pelagic ecosystems, and there have been many recent insights into their ecology and roles in food webs. To examine the trophic ecology of siphonophores (Cnidaria, Hydrozoa), we used bulk (carbon and nitrogen) and compound‐specific (nitrogen) isotope analysis of individual amino acids (CSIA‐AA). We collected samples of 15 siphonophore
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Warm‐adapted sponges resist thermal stress by reallocating carbon and nitrogen resources from cell turnover to somatic growth Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-03-06 Maggioni Federica, Raimbault Patrick, Chateau Olivier, Pujo‐Pay Mireille, Letourneur Yves, Rodolfo‐Metalpa Riccardo
Ocean warming will affect the functioning of coral reef ecosystems with unknown cascading effects. Any perturbation in the ability of sponges to recycle the dissolved organic matter released by primary producers and make it available to higher trophic levels, might have unknown consequences for the reef trophic chain. Biogeochemical processes were measured in the sponge Rhabdastrella globostellata
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Internal wave resonance, surges, and strong nonlinear damping differentiated in two elongated lakes with the aid of an original Green's function Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-03-06 James P. Long, John D. Halfman, Nathan Hawley
While the analogy between the wind‐pumped internal seiche in a lake and the driven damped‐harmonic oscillator is recognized, use of a damped‐oscillator model to understand internal‐wave behavior is seldom attempted due to the irregular waveforms arising from variable winds, and to the presence of nonlinear waves like surges. Using a new variable‐frequency Green's function derived for a damped oscillator
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Grazing strategies determine the size composition of phytoplankton in eutrophic lakes Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-03-02 Sze‐Wing To, Esteban Acevedo‐Trejos, Subhendu Chakraborty, Francesco Pomati, Agostino Merico
Although the general impacts of zooplankton grazing on phytoplankton communities are clear, we know comparatively less about how specific grazing strategies interact with environmental conditions to shape the size structure of phytoplankton communities. Here, we present a new data‐driven, size‐based model that describes changes in the size composition of lake phytoplankton under various environmental
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Isotope effects of O2 consumption in a deep lake as means for understanding partitioning of O2 demand among microorganisms, particles, and sediment Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-29 Israela Musan, Hezi Gildor, Thomas Gonsiorczyk, Hans‐Peter Grossart, Boaz Luz
The isotopic ratio 18O/16O of dissolved O2 in aquatic systems is affected by the preferential biological uptake of 16O (ε). Studies over the past six decades reveal that during incubation experiments, the isotopic effect of microorganism respiration (εorganism) varies in the range of −18‰ to −22‰. In contrast, natural variations in the deep‐ocean O2 concentration and δ18O levels show a considerably
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Zooplankton in northern lakes show taxon‐specific responses in fatty acids across climate‐productivity and ecosystem size gradients Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-29 Fernando Chaguaceda, Danny C. P. Lau, Willem Goedkoop, Mariem Fadhlaoui, Isabelle Lavoie, Tobias Vrede
Northern lakes are facing rapid environmental alterations—including warming, browning, and/or changes in nutrient concentrations—driven by climate change. These environmental changes can have profound impacts on the synthesis and trophic transfer of polyunsaturated fatty acids (PUFA), which are important biochemical molecules for consumer growth and reproduction. Zooplankton are a key trophic link
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Switches between nitrogen limitation and nitrogen–phosphorus co‐limitation in the subtropical North Atlantic Ocean Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-27 Zhongwei Yuan, Eric P. Achterberg, Anja Engel, Minhan Dai, Thomas J. Browning
Concentrations of bioavailable inorganic nitrogen (N) and phosphorus (P) are simultaneously depleted in the (sub)tropical North Atlantic Ocean, but it remains unclear if phytoplankton growth rates are N limited or N–P co‐limited. Here we present findings from three bottle‐scale experiments using a four‐by‐four matrix of low‐level N and P additions, conducted at one site in the subtropical North Atlantic
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Salinity as a key factor affecting viral activity and life strategies in alpine lakes Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-26 Lin Zang, Yongqin Liu, Nianzhi Jiao, Kevin Xu Zhong, Xuanying Song, Yunlan Yang, Lanlan Cai, Keshao Liu, Guannan Mao, Mukan Ji, Rui Zhang
Viruses are major players in the biosphere, yet little is known about their dynamics and life strategies in alpine lakes, particularly those on the Tibetan Plateau. We investigated microbial abundance, viral dynamics, and viral life strategies in 10 high‐altitude Tibetan lakes and found that they harbor high levels of active viruses. Salinity was identified as a crucial factor influencing viral abundance
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Omnivorous summer feeding by juvenile Antarctic krill in coastal waters Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-24 John A. Conroy, Deborah K. Steinberg, Schuyler C. Nardelli, Oscar Schofield
The Antarctic krill Euphausia superba is often considered an herbivore but is notable for its trophic flexibility, which includes feeding on protistan and metazoan zooplankton. Characterizing krill trophic position (TP) is important for understanding carbon and energy flow from phytoplankton to vertebrate predators and to the deep ocean, especially as plankton composition is sensitive to changing climate
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Variability in the phytoplankton response to upwelling across an iron limitation mosaic within the California current system Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-24 YuanYu Lin, Olivia Torano, Logan Whitehouse, Emily Pierce, Claire P. Till, Matthew Hurst, Robert Freiberger, Travis Mellett, Maria T. Maldonado, Jian Guo, Mariam Sutton, David Zeitz, Adrian Marchetti
Coastal upwelling currents such as the California Current System (CCS) comprise some of the most productive biological systems on the planet. Diatoms dominate these upwelling events in part due to their rapid response to nutrient entrainment. In this region, they may also be limited by the micronutrient iron (Fe), an important trace element primarily involved in photosynthesis and nitrogen assimilation
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River network‐scale drying impacts the spatiotemporal dynamics of greenhouse gas fluxes Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-23 Teresa Silverthorn, Naiara López‐Rojo, Romain Sarremejane, Arnaud Foulquier, Vincent Chanudet, Abdelkader Azougui, Rubén del Campo, Gabriel Singer, Thibault Datry
Rivers significantly contribute to global biogeochemical cycles; however, we have a limited understanding of how drying may influence these cycles. Drying fragments river networks, thereby influencing important ecosystem functions such as the processing of carbon and nitrogen, and associated fluxes of greenhouse gases (GHGs) both locally, and at the river network scale. Our objective was to assess
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Stimulation of small phytoplankton drives enhanced sinking particle formation in a subtropical ocean eddy Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-23 Haoran Liu, Thomas J. Browning, Edward A. Laws, Yibin Huang, Lei Wang, Yiwei Shang, Xiaogang Xing, Kuanbo Zhou, Zong‐Pei Jiang, Xin Liu, Bangqin Huang, Minhan Dai
Nutrient transfer into the sunlit surface ocean by cyclonic eddies is potentially crucial for sustaining primary productivity in the stratified subtropical gyres. However, the nature of productivity enhancements, including the flow of matter to higher trophic levels and its impact on carbon fluxes, remain poorly resolved. Here, we report a detailed assessment of the biogeochemical response to a cyclonic
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Blue carbon additionality: New insights from the radiocarbon content of saltmarsh soils and their respired CO2 Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-23 Alex Houston, Mark H Garnett, William E. N. Austin
International policy frameworks recognize the net drawdown and storage of atmospheric greenhouse gases through management interventions on blue carbon ecosystems (saltmarshes, mangroves, seagrasses) as potential emissions offset strategies. However, key questions remain around the “additionality” of the carbon sequestered by these ecosystems, and whether some fraction of the organic carbon (OC) that
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Light-use efficiency for coral reef communities and benthic functional types Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-21 Eric J. Hochberg, Chiara Pisapia, Robert C. Carpenter, Siarah Hall
Coral reef metabolism is dominated by benthic photoautotrophic communities that comprise varying combinations of algae, coral, and sand. Rates of daily gross primary production (GPP) for these benthic functional types (BFTs) are remarkably consistent across biogeographical regions, supporting the idea that reefs exhibit modal metabolism. Most variability in reported rates likely arises from differences
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Nonlinear responses in interannual variability of lake ice to climate change Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-21 David C. Richardson, Alessandro Filazzola, R. Iestyn Woolway, M. Arshad Imrit, Damien Bouffard, Gesa A. Weyhenmeyer, John Magnuson, Sapna Sharma
Climate change is contributing to rapid changes in lake ice cover across the Northern Hemisphere, thereby impacting local communities and ecosystems. Using lake ice cover time-series spanning over 87 yr for 43 lakes across the Northern Hemisphere, we found that the interannual variability in ice duration, measured as standard deviation, significantly increased in only half of our studied lakes. We
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Detritivore physiology and growth benefit from algal presence during microbial leaf colonization Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-16 Alexander Feckler, Sebastian Pietz, Sara Gonçalves, Verena Gerstle, Ute Risse-Buhl, Mirco Bundschuh
In headwater streams, riparian leaf litter is the primary food source for detritivores. While it is well known that aquatic fungi improve the nutritious quality of leaves, our understanding on whether and how benthic algae influence this process remains limited. Here, we hypothesized that the interplay between algae and fungi, termed “algal priming”, further enhances food quality. In a 40-d microcosm
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Environmental driving forces and phytoplankton diversity across the Ross Sea region during a summer–autumn transition Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-16 Antonia Cristi, Cliff S. Law, Matt Pinkerton, Adriana Lopes dos Santos, Karl Safi, Andres Gutiérrez-Rodríguez
The Ross Sea is a highly productive system characterized by a seasonal succession of phytoplankton groups. However, most of the current understanding is based on observations on the continental shelf in spring and summer at relatively coarse taxonomic resolution. Here, we characterize community composition (class to species) using V4-18S rRNA gene metabarcoding on transects to and across the Ross Sea
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Contribution of gas concentration and transfer velocity to CO2 flux variability in northern lakes Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-15 David Rudberg, Jonathan Schenk, Gustav Pajala, Henrique Sawakuchi, Anna Sieczko, Ingrid Sundgren, Nguyen Thanh Duc, Jan Karlsson, Sally MacIntyre, John Melack, David Bastviken
The CO2 flux (FCO2$$ {F}_{{\mathrm{CO}}_2} $$) from lakes to the atmosphere is a large component of the global carbon cycle and depends on the air–water CO2 concentration gradient (ΔCO2) and the gas transfer velocity (k). Both ΔCO2 and k can vary on multiple timescales and understanding their contributions to FCO2$$ {F}_{{\mathrm{CO}}_2} $$ is important for explaining variability in fluxes and developing
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A multiple baseline approach for marine heatwaves Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-07 Luis Giménez, Maarten Boersma, Karen H. Wiltshire
Marine heatwaves and other extreme temperature events can drive biological responses, including mass mortality. However, their effects depend on how they are experienced by biological systems (including human societies). We applied two different baselines (fixed and shifting) to a time series of North Sea water temperature to explore how slowly vs. quickly adapting systems would experience extreme
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Watershed, lake, and food web factors influence diazotrophic cyanobacteria in mountain lakes Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-03 Lara S. Jansen, Daniel Sobota, Yangdong Pan, Angela L. Strecker
Cyanobacterial blooms can occur in freshwater ecosystems largely isolated from development and not experiencing extensive cultural eutrophication. For example, remote mountain lakes can experience intense blooms of diazotrophic (nitrogen-fixing) cyanobacteria caused by factors acting at different spatial and temporal scales. In this study, we examined how cross-scale interactions among watershed, lake
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Water aging and the quality of organic carbon sources drive niche partitioning of the active bathypelagic prokaryotic microbiome Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-03 Marta Sebastián, Pablo Sánchez, Guillem Salazar, Xosé A. Álvarez-Salgado, Isabel Reche, Xosé Anxelu G. Morán, Maria Montserrat Sala, Carlos M. Duarte, Silvia G. Acinas, Josep M. Gasol
Due to the scarcity of organic matter (OM) sources in the bathypelagic (1000–4000 m depth), prokaryotic metabolism is believed to be concentrated on particles originating from the surface. However, the structure of active bathypelagic prokaryotic communities and how it changes across environmental gradients remains unexplored. Using a combination of 16S rRNA gene and transcripts sequencing, metagenomics
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Seasonality strongly affects short-term C-storage in coastal macrophyte communities Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-02-01 Roel Lammerant, Eva Karin Rohlfer, Alf Norkko, Camilla Gustafsson
Ecosystem functions provided by aquatic plants are context dependent and mediated by environmental conditions and plant growth form. This impedes our ability to predict the carbon (i.e., C) sink potential of multispecies coastal meadows characterized by marked seasonal succession of environmental conditions, causing a clear need to explore the distinct patterns of both C capture and release associated
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Denitrification, anammox, and DNRA in oligotrophic continental shelf sediments Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-25 Henry L. S. Cheung, Jenny R. Hillman, Conrad A. Pilditch, Candida Savage, Isaac R. Santos, Ronnie N. Glud, Francisco J. A. Nascimento, Simon F. Thrush, Stefano Bonaglia
Continental shelf sediments are considered hotspots for nitrogen (N) removal. While most investigations have quantified denitrification in shelves receiving large amounts of anthropogenic nutrient supply, we lack insight into the key drivers of N removal on oligotrophic shelves. Here, we measured rates of N removal through denitrification and anammox by the revised-isotope pairing technique (r-IPT)
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Effects of year-long exposure to elevated pCO2 on the metabolism of back reef and fore reef communities Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-24 Peter J. Edmunds, Steve S. Doo, Robert C. Carpenter
The implications of ocean acidification are acute for calcifying organisms, notably tropical reef corals, for which accretion generally is depressed and dissolution enhanced at reduced seawater pH. We describe year-long experiments in which back reef and fore reef (17-m depth) communities from Moorea, French Polynesia, were incubated outdoors under pCO2 regimes reflecting endpoints of representative
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Organic matter, eutrophication, and increased mass accumulation rates in the Anthropocene are the main drivers of mercury concentrations and historical enrichment in Canadian lake sediments Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-24 Marieke Beaulieu, Marc Amyot, Katherine Griffiths, Ashu Dastoor, Adam Jeziorski, Irene Gregory-Eaves
Mercury (Hg) contamination in the environment is a persistent issue as emissions from industry are ongoing and legacy cycling is prolonged. To quantify total mercury (total Hg) and methylmercury (MeHg) concentrations in lake sediments across a wide suite of temperate to subarctic lakes, measurements and modeling were conducted for 320 sites across Canada. Total Hg varied from 7 to 567 ng g−1 dry sediment
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Copepod egg production estimates are biased by female mortality Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-21 Wim J. Kimmerer, Anne M. Slaughter, Toni R. Ignoffo
Egg production rate (EPR, eggs ♀−1d−1) is a key measure of the nutritional state of metazoans such as copepods. Chlorophyll concentration is most often used to index responses of copepod vital rates to ambient food, but the fits to EPR are often poor. A known but unexplored bias in EPR estimates is the interaction between lifetime reproductive schedules of adult females and their mortality. We examined
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Differential dissolution of biogenic silica significantly affects the utility of sediment diatoms as paleoceanographic proxies Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-18 Lihua Ran, Martin G. Wiesner, Yuzhao Liang, Wen Liang, Lanlan Zhang, Zhi Yang, Hongliang Li, Jianfang Chen
Diatoms and biogenic silica (biogenic Si) in sediments are commonly analyzed as paleoceanographic environmental indicators. However, the correspondence between these sedimentary components and their counterparts in the water column above can vary over time and space. This study, undertaken in the northern South China Sea, compares diatoms and biogenic Si in sinking particles from the water column with
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Mixing-driven changes in distributions and abundances of planktonic microorganisms in a large, oligotrophic lake Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-18 Kate A. Evans, Logan M. Peoples, John R. Ranieri, Emma K. Wear, Matthew J. Church
Temperate lakes experience variation in mixing and stratification that affects the distributions, activities, abundances, and diversity of plankton communities. We examined temporal and vertical changes in the composition of planktonic microorganisms (including Bacteria and Archaea) in oligotrophic Flathead Lake, Montana. Using a combination of approaches that included 16S rRNA gene sequencing and
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Size-dependent community patterns differ between microbial eukaryotes and bacteria in a permafrost lake–river–sea continuum Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-18 Marie-Amélie Blais, Alex Matveev, Connie Lovejoy, Warwick F. Vincent
Microbial communities play a crucial role in ecosystem functioning, with contributions that can vary among taxonomic domains and size fractions. However, microbial assembly processes for bacteria and eukaryotes are seldom characterized together using size fractionation, especially in flowing waters. Here, we used amplicon sequencing combined with physicochemical measurements to determine how size fractionated
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Temperature and hypoxia-driven shifts in Daphnia interspecific competition Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-15 Piotr Maszczyk, Karol Krajewski, Konrad Leniowski, Szymon Pukos, Julia Wawrzeńczak, Wojciech Wilczynski, Marcin Lukasz Zebrowski, Jae-Seong Lee, Ewa Babkiewicz
Previous research has shown that elevated temperature and environmental hypoxia are associated with a reduced representation of larger-bodied species in communities of ectotherms, suggesting their competitive disadvantage resulting from increased oxygen demands and limited oxygen availability. To investigate this, we conducted a comparative analysis of two pairs of competing zooplankton species: Daphnia
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Drivers of rising monthly water temperature in river estuaries Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-12 Rei Itsukushima, Kazuaki Ohtsuki, Tatsuro Sato
River estuaries are habitats for a variety of organisms, including many temperature-sensitive species; water temperatures in estuaries are affected by several factors as they are influenced by both terrestrial and marine environments. Therefore, understanding the factors that influence river estuaries are essential for environmental management. However, no information exists on temperature change at
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Seasonal and daily patterns in known dissolved metabolites in the northwestern Sargasso Sea Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-10 Krista Longnecker, Melissa C. Kido Soule, Gretchen J. Swarr, Rachel J. Parsons, Shuting Liu, Winifred M. Johnson, Brittany Widner, Ruth Curry, Craig A. Carlson, Elizabeth B. Kujawinski
Organic carbon in seawater plays a significant role in the global carbon cycle. The concentration and composition of dissolved organic carbon reflect the activity of the biological community and chemical reactions that occur in seawater. From 2016 to 2019, we repeatedly sampled the oligotrophic northwest Sargasso Sea in the vicinity of the Bermuda Atlantic Time-series Study site (BATS) to quantitatively
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Long-term shifts in phenology, thermal niche, population size, and their interactions in marine pelagic copepods Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-10 Stefano Corona, Andrew G. Hirst, David Atkinson, Jasmin Renz, Maarten Boersma, Angus Atkinson
Under climatic warming many species shift their seasonal timing of life cycle events (phenology) and seasonal abundance distribution, but whether they maintain the same thermal niche is still poorly understood. Here, we studied multidecadal trends in abundance and phenology of seven major copepod species across three stations (Stonehaven (SH), Helgoland Roads (HR), and Plymouth L4) on the North–West
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Bidirectional energy subsidies for fish in river mouths of a large lake as revealed by stable isotopes and fatty acids Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-10 Elvita Eglite, Sarah R. Stein, Benjamin A. Turschak, Gabriel J. Bowen, Tomas O. Höök
Freshwater river mouths may facilitate cross-habitat resource use and bidirectional subsidization through (a) active cross-habitat movement by consumers like fish and (b) water and material movement both downstream, from tributary to nearshore lake, and in the opposite direction due to backflow processes. Despite potential importance of freshwater river mouths, relative contributions of lentic and
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Physiological mortality of planktonic ciliates: Estimates, causes, and consequences Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-09 Thomas Weisse
Contrasting physiological mortality with predator-induced mortality is of tremendous importance for the population dynamics of many organisms but is difficult to assess. This is especially true for tiny organisms, such as most protists, which do not leave any carcasses behind. I performed a meta-analysis using planktonic ciliates as model organisms to estimate the maximum physiological mortality rates
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Outwelling of reduced porewater drives the biogeochemistry of dissolved organic matter and trace metals in a major mangrove-fringed estuary in Amazonia Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-10 Melina Knoke, Thorsten Dittmar, Oliver Zielinski, Morimaru Kida, Nils E. Asp, Carlos Eduardo de Rezende, Bernhard Schnetger, Michael Seidel
Mangrove-fringed estuaries are intertidal ecosystems discharging significant amounts of dissolved organic matter (DOM) into coastal oceans. DOM in these ecosystems is derived from autochthonous production, fluvial input, and mangrove porewater outwelling; however, differentiating between these sources remains challenging. Our incomplete understanding of the biogeochemical factors controlling DOM dynamics
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Sediment–vegetation interactions determine the fate of fluvial sediment in the upper reaches of a large estuary Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-09 Cindy M. Palinkas, Cassie Gurbisz, Miles C. Bolton
Feedbacks between sediment and plants in the submersed aquatic vegetation (SAV) beds of the Susquehanna Flats help modulate sediment delivery into the upper Chesapeake Bay from its major tributary (Susquehanna River). Recent modeling work has shown that SAV can steer the river plume, directly controlling sediment transport and fate. However, transport mechanisms likely differ between flood and non-flood
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Region-specific drivers cause low organic carbon stocks and sequestration rates in the saltmarsh soils of southern Scandinavia Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-09 Carmen Leiva-Dueñas, Anna Elizabeth Løvgren Graversen, Gary T. Banta, Jeppe Najbjerg Hansen, Marie Louise Kjærgaard Schrøter, Pere Masqué, Marianne Holmer, Dorte Krause-Jensen
Saltmarshes are known for their ability to act as effective sinks of organic carbon (OC) and their protection and restoration could potentially slow down the pace of global warming. However, regional estimates of saltmarsh OC storage are often missing, including for the Nordic region. To address this knowledge gap, we assessed OC storage and accumulation rates in 17 saltmarshes distributed along the
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Assessing and predicting the influence of chromophoric dissolved organic matter on light absorption by phytoplankton in boreal lakes Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-09 Salla A. Ahonen, Kristiina M. Vuorio, Roger I. Jones, Heikki Hämäläinen, Krista Rantamo, Marja Tiirola, Anssi V. Vähätalo
Many boreal lakes are colored brown due to strong light absorption by chromophoric dissolved organic matter (CDOM), which reduces light penetration into the water column. However, the influence of CDOM on the fraction of photosynthetically utilizable radiation (PUR) absorbed by phytoplankton from the photosynthetically active radiation (PAR) entering the lake (i.e., PUR/PAR) remains largely unknown
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Physiological and interspecific factors determine diel changes in phytoplankton bio-optical properties Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-07 Nicholas Baetge, Kimberly H. Halsey, Jason R. Graff, Brian Ver Wey, Toby K. Westberry, Amanda E. Appel, Guillaume Bourdin, Charlotte Begouen Demeaux, Emmanuel Boss, Michael J. Behrenfeld
Bio-optical properties of marine phytoplankton retrieved through satellite remote sensing are used to estimate ocean productivity and carbon cycling. Daily activity of phytoplankton is attuned to the predictable light fluctuations of the diel cycle. Field and laboratory studies have documented diel changes in phytoplankton growth, division, and respiration, carbon and pigment content, cell size, photosynthetic
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Monitoring ecological dynamics on complex hydrothermal structures: A novel photogrammetry approach reveals fine-scale variability of vent assemblages Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-05 Loïc Van Audenhaege, Jozée Sarrazin, Pierre Legendre, Garance Perrois, Mathilde Cannat, Aurélien Arnaubec, Marjolaine Matabos
We set out to characterize the fine-scale processes acting on interannual dynamics of deep-sea vent fauna by using a novel approach involving a 5-yr time series of 3D photogrammetry models acquired at the Eiffel Tower sulfide edifice (Lucky Strike vent field, Mid-Atlantic Ridge). Consistently, with the overall stability of the vent edifice, total mussel cover did not undergo drastic changes, suggesting
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Tracing the fate of seabird-derived nitrogen in a coral reef using nitrate and coral skeleton nitrogen isotopes Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-03 Noémie Choisnard, Nicolas Noel Duprey, Tanja Wald, Martin Thibault, Fanny Houlbrèque, Alan D. Foreman, Pascale Cuet, Mireille M. M. Guillaume, Hubert Vonhof, Daniel M. Sigman, Gerald H. Haug, Jean-François Maguer, Stéphane L'Helguen, Alfredo Martínez-García, Anne Lorrain
Seabirds transfer nutrients from the ocean to their nesting island, potentially altering nitrogen (N) cycling within adjacent terrestrial and marine ecosystems. Yet, the processes involved in seabird-N transfer along the land–sea continuum remain elusive. Using δ15N and δ18O measurements of groundwater nitrate, we demonstrate the role of brackish groundwater located within a coral island's landmass
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Nitrogen enrichment decreases seagrass contributions to refractory organic matter pools Limnol. Oceanogr. (IF 4.5) Pub Date : 2024-01-03 Hongxue Luo, Songlin Liu, Stacey M. Trevathan-Tackett, Yuzheng Ren, Jiening Liang, Jinlong Li, Zhijian Jiang, Yunchao Wu, Xiaoping Huang
Coastal nitrogen enrichment significantly contributes to the decline of seagrass health and habitat, thereby diminishing its capacity to capture and sequester carbon (i.e., Blue Carbon). However, the consequences to blue carbon stocks due to sublethal changes in chemical recalcitrance of seagrass organic matter (OM) caused by nitrogen enrichment is unknown. In this study, we investigated the effects
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Aggregation of zooplankton in a Stommel Retention Zone in a laboratory model of Langmuir circulation Limnol. Oceanogr. (IF 4.5) Pub Date : 2023-12-28 Sanjib Gurung, Kevin T. Du Clos, Abdullah Aldaddi, David W. Murphy
Langmuir circulation is a common form of surface turbulence comprising a series of counterrotating horizontal vortex pairs. Upwellings and downwellings in Langmuir circulation may suspend and trap passive particles or active swimmers like zooplankton in regions known as Stommel Retention Zones. For zooplankton, Stommel Retention Zone formation depends on flow speed and animal swimming speed and direction
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Ingestion and respiration rates of a common coastal mysid respond differently to diurnal temperature fluctuation Limnol. Oceanogr. (IF 4.5) Pub Date : 2023-12-28 Konstanze Brinkop, Laura M. Wienhausen, Erik Sperfeld, Alexander Wacker
Animals face strong environmental variability even on short time scales particularly in shallow coastal habitats, forcing them to permanently adjust their metabolism. Respiration rates of aquatic ectotherms are directly influenced by water temperature, whereas ingestion rates might additionally be influenced by behavior. We aim to understand how respiration and ingestion rates of an aquatic invertebrate
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Predicting the presence of hypoxic hypolimnia in lakes at large spatial scales Limnol. Oceanogr. (IF 4.5) Pub Date : 2023-12-28 Richard LaBrie, Roxane Maranger
Lakes and reservoirs provide multiple essential ecosystem services to humans, and several of these require the presence of a cool, oxygen-rich hypolimnion. These ecosystem services include supporting habitat for recreational fish species and the maintenance of a non-eutrophic state by limiting internal nutrient loading. However, changes in land use and global warming are modifying the thermal structure
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Nitrogen availability regulates the effects of a simulated marine heatwave on carbon sequestration and phycosphere bacteria of a marine crop Limnol. Oceanogr. (IF 4.5) Pub Date : 2023-12-26 Meijia Jiang, Jason M. Hall-Spencer, Lin Gao, Zengling Ma, Guang Gao
Great hope has been pinned on seaweed cultivation as being a potent way of removing CO2 to reduce rates of sea surface warming and acidification. Marine heatwaves and nitrogen pollution in coastal ecosystems are serious current issues that need to be better understood to inform decision making and policy. Here, we investigated the effects of a simulated heatwave and nitrogen pollution on carbon sequestration
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The role of seasonal hypoxia and benthic boundary layer exchange on iron redox cycling on the Oregon shelf Limnol. Oceanogr. (IF 4.5) Pub Date : 2023-12-23 Natalya Evans, Alexis E. Floback, Justin Gaffney, Peter J. Chace, Zachary Luna, Joël Knoery, Clare E. Reimers, James W. Moffett
Widespread hypoxia occurs seasonally across the Oregon continental shelf, and the duration, intensity, and frequency of hypoxic events have increased in recent years. In hypoxic regions, iron reduction can liberate dissolved Fe(II) from continental shelf sediments. Fe(II) was measured in the water column across the continental shelf and slope on the Oregon coast during summer 2022 using both a trace
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Harmonizing marine zooplankton trait data toward a mechanistic understanding of ecosystem functioning Limnol. Oceanogr. (IF 4.5) Pub Date : 2023-12-22 Patrick R. Pata, Brian P. V. Hunt
Compiling trait information promotes discovery and innovation in using trait-based approaches in ecology. Various zooplankton trait datasets are stored in unlinked data repositories, in diverse data structures, and have varying levels of complexity. These require standardization and harmonization to allow interoperability and to limit the duplication of efforts in the time-consuming and error-prone
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Recycling and deposition of inorganic carbon from calcium carbonate encrustations of charophytes Limnol. Oceanogr. (IF 4.5) Pub Date : 2023-12-18 Małgorzata Strzałek, Lech Kufel, Karina Apolinarska, Marcin Becher, Elżbieta Biardzka, Michał Brzozowski, Rafał Kiełczewski, Grzegorz Kowalewski, Andrzej Pukacz, Michał Woszczyk, Mariusz Pełechaty
Many aquatic primary producers can use bicarbonates as a carbon source for photosynthesis. Charophytes of the two genera: Chara and Nitellopsis are quite efficient in this process. Some species of these macroalgae produce carbonate encrustations, mainly calcium carbonate, constituting up to 86% of the summer maximum dry weight of the standing crop. In this study, we analyzed the fate of inorganic carbon
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The distribution of depth, volume, and basin shape for lakes in the conterminous United States Limnol. Oceanogr. (IF 4.5) Pub Date : 2023-12-18 Keenan J. Ganz, Max R. Glines, Kevin C. Rose
Depth regulates many attributes of aquatic ecosystems, but relatively few lakes are measured, and existing datasets are biased toward large lakes. To address this, we used a large dataset of maximum (Zmax; n = 16,831) and mean (Zmean; n = 5,881) depth observations to create new depth models, focusing on lakes < 1,000 ha. We then used the models to characterize patterns in lake basin shape and volume
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Uncertainty sources for measurable ocean carbonate chemistry variables Limnol. Oceanogr. (IF 4.5) Pub Date : 2023-12-14 Brendan R. Carter, Jonathan D. Sharp, Andrew G. Dickson, Marta Álvarez, Michael B. Fong, Maribel I. García-Ibáñez, Ryan J. Woosley, Yuichiro Takeshita, Leticia Barbero, Robert H. Byrne, Wei-Jun Cai, Melissa Chierici, Simon L. Clegg, Regina A. Easley, Andrea J. Fassbender, Kalla L. Fleger, Xinyu Li, Macarena Martín-Mayor, Katelyn M. Schockman, Zhaohui Aleck Wang
The ocean carbonate system is critical to monitor because it plays a major role in regulating Earth's climate and marine ecosystems. It is monitored using a variety of measurements, and it is commonly understood that all components of seawater carbonate chemistry can be calculated when at least two carbonate system variables are measured. However, several recent studies have highlighted systematic