Tropical lakes experience less thermal convection than temperate lakes and can be stably stratified by temperature gradients alone. Deep tropical lakes are often presumed meromictic, but conditions for sustained meromixis are poorly constrained. Here, we investigate the stratification stability of a deep (200 m) tropical Lake Towuti (Indonesia) and analyze its sensitivity to meteorological and climatic

The transport of particulate organic carbon (POC) from land to deep‐sea sediments is a critical component of the global carbon cycle. However, the transport processes of terrestrial POC across continental shelves remain poorly understood due to the complexity of these systems. In this study, we investigated the vertical fluxes and fates of terrestrial vs. marine POC using stable carbon isotope ratios

Inland waters emit a globally significant amount of methane (CH4) into the atmosphere. Measurements of potential CH4 production rates in the sediment can help constrain the magnitude of CH4 sources and time‐averaged emission rates. We explored the magnitude, variability, and drivers of potential CH4 production rates in the sediment, based on compiled measurements (238 sediment cores from 72 aquatic

Periphyton plays an important functional role in shallow lakes and is sensitive to variation in nutrient availability and global warming. Understanding the responses of periphyton to changes in nutrient availability in contrasting warming scenarios can contribute to the development of more efficient techniques for the restoration of lakes in a future warmer world. We analyzed the periphyton response

Viral lysis accounts for approximately 50% of prokaryotic mortality, significantly influencing the diversity, composition, and succession of prokaryotic communities. Despite its importance, the specific influence of viral lysis on seasonal dynamics within aquatic ecosystems remains poorly understood. In this study, we investigated the seasonal dynamics of prokaryotes in the river–estuary–coastal ecosystem

Terrestrial run‐off is increasing in temperate lakes due to climate change and can lead to loading of colored dissolved organic matter (cDOM) and nutrients, thus reducing light availability and increasing carbon, nitrogen, and phosphorus. Run‐off events are highly irregular, resulting in temporal resource variability that may determine the energy flow in planktonic communities. To understand the effects

Dinitrogen (N2)‐fixing microorganisms play a crucial role in supplying nitrogen (N) to the oceans by converting atmospheric N2 into bioavailable N. N2 fixation was thought to be limited to warm oligotrophic ocean waters, but the association between the N2‐fixing UCYN‐A cyanobacterium and specific haptophytes, including Braarudosphaera bigelowii and relatives, has been found in diverse ocean environments

Diatom‐dominated blooms in coastal upwelling systems contribute disproportionately to global primary production. The fate of carbon captured during a diatom bloom is often influenced by species‐specific ecological differences. However, successional patterns that take place during a diatom bloom are often oversimplified, and the diversity of diatom adaptations to different stages of a bloom remains

Corals with high trophic plasticity, i.e., the ability to change the relative contribution of heterotrophic and autotrophic nutrition to their mixotrophic diet, can have increased tolerance to individual stressors, but it is poorly understood how trophic strategies shift in response to combined global (e.g., warming, acidification) and local stressors (e.g., nutrient input). Furthermore, it remains

Phytoplankton often rely on the regeneration of ammonium () to produce biomass and, for some cyanobacteria, nitrogen‐rich toxins, despite low or unmeasurable concentrations in water. Thus, measuring turnover rates (i.e., uptake and regeneration) is necessary to determine its actual availability. The objectives of this study were to quantify water column turnover rates in two large, shallow, eutrophic

Spatial environmental heterogeneity is an important driver of aquatic biodiversity. Ecological and evolutionary theory often consider spatial heterogeneity as being driven by exogenous factors, yet heterogeneity can also be generated and modified by organisms. Here we used a mesocosm experiment to investigate if consumers influence the build‐up of spatial heterogeneity. We expected that consumer effects

The introduction and extirpation of predators can have large impacts on food web structure and ecosystem function. The magnitude of these predator effects can be influenced by species diversity and turnover along environmental gradients in space or time, which have the potential to buffer or magnify the impact of trophic interactions on ecosystem functioning. In this study, we explored the individual

The maintenance of soil surface elevation in mangroves supports the persistence of mangroves with sea level rise. The processes contributing to soil surface elevation have rarely been assessed in the humid tropics, despite most mangroves occurring in river deltas and tidal estuaries within this climate zone. Using surface elevation table (SET) with marker horizon methods over sites that occurred on

The occurrence of oxic methane production (OMP) has been reported for numerous aquatic ecosystems. Its seasonal dynamics and contribution to global methane () emissions remains uncertain, however, due to the lack of measurements constraining the spatial and temporal variability of OMP. In this study, we used data collected over 4 yrs with three types of models to estimate the net production/consumption

Understanding dissolved concentrations of the essential coenzyme thiamin (vitamin B1) can provide insights into the biological controls on highly productive upwelling systems such as the California Current Ecosystem. To connect thiamin availability with microbial communities in the California Current Ecosystem, we measured concentrations of dissolved thiamin and its biochemically related moieties (thiamin

The Southern Ocean is a critical region for global biogeochemical cycles, particularly for carbon dioxide uptake and organic carbon export, partly driven by extensive phytoplankton blooms. In naturally iron‐fertilized regions of this otherwise iron‐limited ocean, these blooms are primarily driven by diatoms. Variability in bloom occurrences on spatiotemporal scales makes it challenging to track and

Wave attenuation in partially vegetated aquatic environments remains an underexplored area of research. This study addresses this gap by conducting laboratory experiments to examine the influence of vegetation on wave dynamics. The wavelength‐to‐vegetation spacing ratio is essential to quantifying the behavior of the waves within and around vegetated areas. Laboratory experiments measure wave height

The benthic flux of nutrients underpins marine food webs, influences conditions for life in the oceans, and contributes to climatic feedback. Estimates of these fluxes' contributions to macro‐ and micronutrient cycles are, however, highly variable, generating significant uncertainty in biogeochemical models. Traditional benthic flux methodologies have potentially significant limitations, and in geochemically

Ocean alkalinity enhancement (OAE) is a widely considered marine CO2 removal method. Ocean alkalinity enhancement works by converting seawater CO2 into and by electrochemical methods or the addition of alkaline minerals. Although OAE does not require biology to remove CO2, the perturbations caused by OAE may affect marine organisms. Due to logistical challenges, it is likely that alkalinity additions

This study presents the first high‐resolution spatial analysis of carbonate chemistry on Georges Bank, a highly productive shallow bank located at the southeastern edge of the Gulf of Maine. Despite numerous studies on the hydrography, nutrient chemistry, and biology, regional carbonate chemistry remains unexplored, in particular for near‐bottom conditions. Observations from cruises in May and October

The North Sea has been identified as an area where the impacts of climate change and de‐eutrophication efforts are already apparent, specifically on phytoplankton communities, with shifts in biogeography, altered species composition, and increased biomass of harmful algal bloom (HAB) species. Here, we test whether environmental changes in the Dutch North Sea are associated with changes in the abundances

Eutrophication in the Baltic Sea has caused an imbalance in the inorganic nitrogen (N) to phosphorus (P) ratio, leaving excess phosphate (PO4) after the phytoplankton spring bloom that terminates after N depletion. Using monitoring data, we demonstrated that the PO4 concentration has continued to increase in the outermost Gulf of Finland during past decades. We further investigated the fate of such

Few in situ measurements are conducted early in the productive season in the Arctic Ocean, making it difficult to accurately assess the impact of the recent decline in sea ice cover on algal fluxes. Since 2017, time‐series sediment traps have been deployed to collect sinking particles at two sites in the Pacific Arctic region. Here, we present algal fluxes obtained in the East Siberian Sea (ESS) and

Despite the role of extracellular vesicles (EVs) in genetic and biogeochemical exchange in the ocean, there is a notable dearth of studies delving into the seasonal annual dynamics of EVs in uncultured microbial communities. Here, quantitative data from the oligotrophic Mediterranean Sea revealed that EVs mL−1 ranged from 104 to 106 throughout the year and correlated with microbial abundances (correlation

The impact of chromophoric dissolved organic matter (CDOM) on the spectral underwater light field within photosynthetically active radiation (PAR), and the related responses of spectral phytoplankton light absorption are poorly documented in the mixed layer of lakes. We examined how CDOM influences the spectrum of lake optical properties, underwater light field, photons absorbed by phytoplankton, photoacclimation

Methanol metabolism is important in marine carbon cycling, while the control of metabolic mode and activity remains poorly constrained, particularly in coastal waters. Here, we investigated the biogeochemical cycling of methanol across the estuary–coast–shelf continuum of the East China Sea. Methanol concentrations varied from < 12.3 to 617.3 nmol L−1, decreasing from coast to shelf. The total uptake

Diel vertical movement (DVM) is a widespread behavior in aquatic ecosystems, occurring across a variety of taxa and water bodies. The factors hypothesized to drive DVM can vary tremendously through time, yet little is known about how DVM changes at interannual timescales. Here we explore how cyclical prey abundance affects predator DVM. Higher consumption levels increase the optimal temperatures for

Uncertainties in the temporal and spatial patterns of marine primary production and respiration limit our understanding of the ocean carbon (C) cycle and our ability to predict its response to environmental changes. Here we present a comprehensive time‐series analysis of plankton metabolism at the Hawaii Ocean Time‐series program site, Station ALOHA, in the North Pacific Subtropical Gyre. Vertical

Tidal wetland reclamation is a worldwide issue that profoundly alters ecological functions and ecosystem service provisions; however, its impacts on sediment microbial communities and functions remain poorly understood. Here, we investigated the spatial and seasonal patterns of greenhouse gas (GHG) production in response to land use change in mangrove wetlands and elucidated the underlying mechanisms

Phytoplankton chlorophyll Sun‐induced fluorescence is observable in the upwelling light field of the ocean. This allows its observation by radiometers in situ or on satellite sensors. Since it is influenced by both biomass and physiology it can potentially provide information about both. Since fluorescence yield is complementary to photosynthesis and heat in photosystem II, its observation throughout

Documenting the variations of phytoplankton pigments is essential for understanding phytoplankton assemblages' dynamics and physiological characteristics in the global oceans. Advanced chlorophyll a 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

The expansion of autonomous observation platforms offers vast opportunities for analyzing ocean ecosystems and their role in carbon export. As part of the EXport Processes in the Ocean from RemoTe Sensing campaign, we autonomously measured the productivity regimes in two contrasting end‐member ecosystem states. The first campaign occurred in the subpolar North Pacific near Ocean Station Papa (Site

Microplastics (particles < 5 mm) are pollutants of emerging concern in aquatic ecosystems worldwide. Streams are key sites of microplastic input, retention, and transport, and empirical measurements of microplastic movement in lotic ecosystems are needed to inform global microplastic budgets. However, factors that influence microplastic retention in lotic ecosystems are not well studied. We used particle

How much of the excess CO2 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”) CO2 production, what processes drive these patterns, and

The attraction‐production continuum in fishery management centers on the extent to which artificial reefs increase fish production or whether they simply redistribute fish. Reef systems could produce carbon to support growth of higher trophic levels. Therefore, we aimed to understand carbon flows at lower trophic levels on shallow‐water (11 m) artificial reefs within a region which hosts an extensive

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

Microcrustaceans of the genus Daphnia 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 Daphnia pulex in response to infochemicals from predatory larvae of Chaoborus, which prey on juvenile instars of

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

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

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

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

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, Cerastoderma edule and Macoma balthica, to different heatwave intensities in a mesocosm experiment under near‐natural environmental

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

Understanding the ocean's capacity potential to store dissolved organic carbon (DOC) is essential for predicting its role in long‐term carbon sequestration and climate regulation. This capacity hinges on the behavior of DOC at elevated concentrations, a critical yet unresolved question that has produced mixed results due to narrow concentration ranges tested previously and limited molecular insights

Escalating high‐energy hydrodynamic events, like storms, represent a significant manifestation of global climate change, causing detrimental impacts on various ecosystems and potentially triggering thresholds that result in abrupt shifts in ecosystem states. Despite the potential of such thresholds, few studies have explicitly addressed them. This gap is particularly notable for subtidal ecosystems

Oceanic emission is a primary source of brominated very short‐lived substances (BrVSLs) to the atmosphere, which have important effects on stratospheric ozone chemistry. Marine biogeochemical processes regulating BrVSLs are often sensitive to ocean acidification. Yet, the response of BrVSLs production to acidification remains poorly understood. Herein, the effects of acidification on the production

Salt marshes are vital but vulnerable ecosystems. However, our understanding of disturbance‐induced dieback and recovery processes in multi‐specific marshes remains limited. This study utilized remote sensing data (2001–2021) to analyze a dieback event and subsequent recovery in the multi‐specific San Felice marsh within the Venice lagoon, Italy. A significant dieback of Spartina maritima (Spartina)

Organic carbon (OC) burial in lake sediments is comparable to that in marine sediments globally. However, climatic and carbon cycle implications depend on the origin of buried OC. This study utilizes high‐resolution radiocarbon (14C) measurements in combination with stable carbon isotopes (13C) and total organic carbon/total nitrogen ratios to constrain sources and ages of OC deposited since the early

Cell surface properties can strongly mediate microbial interactions with predators in soil and host‐pathogen systems. Yet, the role of microbial surface properties in avoiding or enhancing predation in the ocean is less well known. Appendicularians are globally abundant marine suspension feeders that capture marine microorganisms in a complex mucous filtration system. We used artificial microspheres