Coastal wetlands are highly sensitive to changes occurring at the coastline. It is critically important to determine region-specific projections for these areas due to their specificities and vulnerabilities to climate change. This work aimed to value the impacts of recent climate changes at West Africa Sahara coastland, southern Morocco, at Khnifiss Lagoon. We have applied a combined approach using

Anaerobic oxidation of methane (AOM) is a potentially important methane sink in lake sediments, but the biogeochemistry and microbial ecology of this process are understudied. Potential electron acceptors for AOM include Fe(III) and sulfate; however, it is not clear to which extent low sulfate concentrations constrain the coupling of AOM to sulfate reduction, nor if Fe(III) reduction drives AOM directly

Animals that disrupt sediments through burrowing or foraging contribute to ecosystem function through bioturbation and ecosystem engineering processes linked to their excavation behavior. Empirical evidence linking behavior with function is rare; yet this information is critical for assessing species-specific functional roles. Using two stingray species, Himantura australis and Pastinachus ater, as

Photosynthesis and respiration cause distinct chemical microenvironments within cyanobacterial aggregates. Here, we used microsensors and a diffusion–reaction model to characterize gradients in carbonate chemistry and investigate how these are affected by ocean acidification in Baltic vs. Pacific aggregates (Nodularia and Dolichospermum vs. Trichodesmium). Microsensor measurements of O2 and pH were

Foundation species play a disproportionate role in maintaining biodiversity and ecosystem functioning. Improved understanding of how environmental factors influence the distribution and population structure of foundation species therefore contributes to management and conservation of entire ecosystems. We surveyed subtidal kelp forests within four regions of the U.K., distributed over 9° of latitude

Coral populations from reef habitats that experience extreme daily abiotic fluctuations have been suggested as candidates to survive and proliferate under future climate change. Few studies, however, have exposed corals from dynamic environments to the synergistic effects of ocean warming and acidification to investigate whether tolerance of present-day environmental variability is maintained under

Diel vertical migration (DVM) is a common behavior among marine organisms to balance the trade-off between surface feeding opportunities and predation-related mortality risk. Body size is a master trait that impacts predation risk to both visual and nonvisual predators. Acoustic measurements from the autonomous Zooglider revealed size-dependent DVM behaviors in the San Diego Trough. Dual frequency

Multiple biogeochemical processes in estuaries modulate the flux of nutrients from land to sea, thus contributing to the coastal filter. The role of particle dynamics in regulating the fate of terrestrial nutrients in estuaries is poorly constrained. To address this issue, we resolved the particle size distribution of suspended material, and quantified size-fractionated particulate nitrogen (PN) and

We present concentrations of total particulate carbon (PC), carbonate (PIC), total particulate nitrogen (PN), 13C and 15N of suspended particles along a North Pacific transect. In the upper 400 m, suspended PIC to particulate organic carbon (POC) ratios generally follow published sinking PIC/POC ratios. Below 600 m, suspended PIC/POC become significantly lower than sinking PIC/POC, likely indicating

Mesophotic coral ecosystems (30–150 m depth) present a high oceanic biodiversity, but remain one of the most understudied reef habitats, especially below 60 m depth. Here, we have assessed the rates of photosynthesis and dissolved inorganic carbon (DIC) and nitrogen (DIN) assimilation by Symbiodiniaceae associated with four soft coral species of the genus Sinularia and two stony coral species of the

Phytoplankton blooms are a global water quality issue, and successful management depends on understanding their responses to multiple and interacting drivers, including nutrient loading and climate change. Here, we examine a long-term dataset from Lake 227, a site subject to a fertilization experiment (1969–present) with changing nitrogen:phosphorus (N:P) ratios. We applied a process-oriented model

Unicellular photoautotrophic diazotrophs such as Crocosphaera spp. are ubiquitous in many oligotrophic and N-limited oceans, as they can reduce N2 into bioavailable ammonia. The Mediterranean Sea is potentially an ideal environment for photoautotrophic diazotrophic activity, and yet N2-fixation rates measured in the last two decades are typically very low and no diazotrophic blooms have been recorded

The occurrence of regime shifts in marine ecosystems has important implications for environmental legislation that requires setting reference levels and targets of quantitative restoration outcomes. The Baltic Sea ecosystem has undergone large changes in the 20th century related to anthropogenic pressures and climate variability, which have caused ecosystem reorganization. Here, we compiled historical

Phytoplankton dynamics in coastal ecosystems is increasingly altered by land-based human activities. Yet, this global vision conceals major disparities, among sites and through time. As conventional monitoring time series are quite sparse and relatively short, biological records of environmental variability appear as relevant tools to gain insights into phytoplankton dynamics over larger temporal and

Human-induced expansion of oxygen-deficient zones can have dramatic impacts on marine systems and its resident biota. One example is the formation of the potent neurotoxic methylmercury (MeHg) that is mediated by microbial methylation of inorganic divalent Hg (HgII) under oxygen-deficient conditions. A negative consequence of the expansion of oxygen-deficient zones could be an increase in MeHg production

Phytoplankton are key players in global biogeochemical cycles, and the effects of ocean warming on their carbon–nitrogen–phosphorus (CNP) stoichiometry, photosynthesis, size, morphology, growth rates, and other traits are of great ecological consequence. The physiological mechanisms of adaptation to temperature in phytoplankton are poorly understood, as are the consequences of the evolution of these

Lakes in human-dominated landscapes often face high loads of nutrients that may alter ecosystem function. High N loads relative to P are especially common in agricultural watersheds, where nitrate (NO3) in particular is elevated due to fertilizer application and runoff. While past research has focused extensively on the impact of nutrient loads on reductions in water quality, we still lack assessment

Light affects iron (Fe) growth requirements in marine phytoplankton while CO2 can influence energy allocation and light sensitivity. Therefore, ongoing increases in seawater CO2 concentrations could impact the growth of Fe- and light-limited phytoplankton. In this study, Phaeodactylum tricornutum was used as a model diatom to examine the interactive effects of Fe, light, and CO2 on photosynthesis,

Marine microorganisms comprise a large fraction of ocean carbon and are central players in global biogeochemical cycling. Significant gaps remain, however, in our understanding of processes that determine the fate, distribution, and community structure of microbial communities. Protists and viruses are accepted as being part of the microbial loop and a source of microbial mortality. However, pelagic

The warming ocean is expected to be more phosphorus (P) limited due to increasing stratification. P is a major limiting nutrient of marine diazotrophs, while the interactive effect of temperature elevation and P limitation on marine unicellular diazotrophs is unknown. Here, we examined the physiology of a major unicellular diazotroph, Crocosphaera watsonii, grown under P-limited and P-replete conditions

Microbial organic matter decomposition is a critical ecosystem function, which can be negatively affected by chemicals. Although the majority of organic matter is stored in sediments, the impact of chemicals has exclusively been studied in benthic systems. To address this knowledge gap, we assessed the impact of a fungicide mixture at three concentrations on the decomposition of black alder leaves

Natural ecosystems are experiencing unprecedented rates of change due to anthropogenic activities and global change, leading to either gradual changes in a given response or tipping points. While the tipping point concept has been tested in an array of habitats since the 1960s, the spatiotemporal superposition of multiple drivers in different ecosystems needs to be considered when investigating the

Seascape ecology is an emerging pattern-oriented and integrative science conceptually linked to landscape ecology. It aims to quantify multidimensional spatial structure in the sea and reveal its ecological consequences. The seascape ecology approach has made important advances in shallow coastal environments, and increasing exploration and mapping of the deep seabed provides opportunities for application

Biotic and abiotic processes control the formation and evolution of tidal channel networks. However, which factor regulates the planimetric geometry of the network remains unclear. Here, we compare the geometric properties of tidal channel networks in 14 salt marshes along the coasts of the United States and China. Significant difference in the geometric properties of tidal channel networks was found

Allochthonous subsidies to marine ecosystems have mainly focused on biogeochemical cycles, but there has also been recent interest in how terrestrial carbon (C) influences marine food webs. In the Baltic Sea, pine (Pinus sylvestris) pollen is found in large amounts in shallow bays in early summer. Pollen is a significant C-source in freshwater ecosystems and may also be important in coastal food webs

Marsh plants are typically composed of leaves attached to a central stem. Both the leaves and the stem are flexible and contribute to wave attenuation. This study developed a model to predict wave damping within a marsh based on a simple representation of the wave-induced drag on an individual, flexible marsh plant. Specifically, the drag force on the leaves and the stem was represented separately

Many seaweed species are particularly important for passive marine dispersal, yet relatively little is known about their floating and stranding dynamics. Here, we studied these dynamics for two kelp species over four consecutive years at mid-latitudes (30°S). Floating kelps were found during all seasons, but Macrocystis pyrifera was always more abundant than Durvillaea incurvata. Highest floating biomasses

There is a growing consensus that traits offer a powerful way to examine the relationship between the environment, organismal strategies, species interactions, and ecological success. To date, trait-based research has largely been focusing on individual trophic levels and not on cross-level interactions. Looking at traits not only within but across trophic levels and identifying traits that together

Over 40 years ago, it was suggested that Prorocentrum minimum in Chesapeake Bay has a seasonal life strategy that depends on the physical transport by estuarine circulation, bringing cells from lower bay to the mid-bay in spring when they bloom. In this study, a validated hydrodynamic-biogeochemical model is used to simulate the annual cycles of P. minimum in Chesapeake Bay and track its life history

Epibenthic biofilms are important in regulating nitrogen (N) fluxes in stream ecosystems. The efficiency of the regulation is controlled by hydraulic and biological processes and their interactions. However, knowledge on the underlying physical and biological processes, their controlling parameters, and interactions in stream ecosystems is still limited. To analyze the relative importance of hydraulic

We studied time-series fluxes of radiolarian particles collected by two sediment traps deployed at the eastern (Sta. NAP12t) and western (Sta. CAP12t) sides of the Chukchi Borderland in the Chukchi Sea from 04 October 2012 to 18 September 2013. In order to elucidate the contribution of radiolarian skeletons to the biogenic silica flux, a three-dimensional (3D) imaging technique using microfocus X-ray

Body size is a fundamental trait in ecology, and body size reduction with increasing temperature has been termed the third universal response to climate warming. Although effects of temperature and food on phenotypic plasticity of zooplankton adult body size have been investigated, density-dependent effects have been neglected. We measured seasonal changes in the prosome length of 7098 adult females

Harmful algal blooms (HABs) are globally increasing in number and spatial extent. However, their propagation dynamics along environmental gradients and the associated interplay of abiotic factors and biotic interactions are still poorly understood. In this study, a nutrient gradient was established in a linear meta-ecosystem setup of five interconnected flasks containing an artificially assembled phytoplankton

Despite being a major component in the mangrove carbon (blue carbon) budget, “outwelling” flux (or export to the sea) has gained little attention relative to other biogeochemical fluxes and reservoir carbon stock estimations. This study aims to estimate lateral exchange fluxes of dissolved and particulate organic carbon (DOC, POC) and dissolved inorganic carbon (DIC) from the watershed through a microtidal

Despite their importance in shaping the structure and function of marine microbial food webs, little is known about factors regulating marine virus abundance. Previous work demonstrated clearance of laboratory-cultured Emiliania huxleyi virus by the appendicularian Oikopleura dioica; however, the applicability of this interaction to natural virus assemblages was not investigated. Here, we conducted

Arid zone coastal wetlands provide disproportionally important ecosystem services due to their relatively high levels of productivity relative to adjacent terrestrial systems. However, these wetlands are vulnerable to sea level rise as sediments needed for vertical accretion are limited. In order to assess the processes important for vertical accretion in arid zone coastal wetlands, we assessed vertical

Ocean acidification, due to the increase of carbon dioxide (CO2) concentration in the atmosphere and its absorption by the oceans, affects many aspects of marine calcifying organisms' biology, including reproduction. Most of the available studies on low pH effects on coral reproduction have been conducted on tropical species under controlled conditions, while little information is reported for either

The temporal dynamics of dissolved organic matter (DOM) are inherently linked with the functioning of aquatic ecosystems. Because DOM represents a complex mixture of millions of different compounds, the statistical analysis of DOM dynamics poses a huge challenge. Here, we present a statistical approach based on hierarchical clustering of time series that groups DOM compounds with synchronous dynamics

A field experiment study of flow transport around a coral reef was conducted at Scott Reef, an offshore atoll in the Timor Sea. A drifter deployment was designed based on the insight derived from two Lagrangian data analysis approaches, the finite-time Lyapunov exponent method and the optimized-parameter spectral clustering method, which were used to analyze the predictions of a numerical model. This

Herbicide use has increased very rapidly worldwide in recent decades, and some of these herbicides eventually enter the ocean. At present, herbicide pollution in the ocean has become a global environmental problem. Here, in a field investigation of 22 commonly used herbicide residues (triazine, phenylurea, and amide) in the Bohai Sea and the Yellow Sea, we found that the detection rate of herbicide

Ocean acidification is perceived to be a major threat for many calcifying organisms, including scleractinian corals. Here, we investigate (1) whether past exposure to low pH environments associated with CO2 vents could increase corals tolerance to low pH and (2) whether zooxanthellate corals are more tolerant to low pH than azooxanthellate corals. To test these hypotheses, two Mediterranean colonial

Zooplankton carcasses are an important, yet understudied, pathway of the biological gravitational pump. To understand their contribution to the downward carbon flux in the subantarctic, carcasses of the copepod Neocalanus tonsus were analyzed for carbon content, microbial remineralization rates, and sinking velocities. In addition, the sensitivity of carcass flux to varying mortality, microbial turnover

The critical role of marginal seas in the global carbon cycle and their response to climate and circulation changes are not well understood. In this study, we used long-term archives of sedimentary CaCO3 data and a conceptual model to systematically determine the spatial and vertical features of the sediment carbonate system in the marginal seas along the Western Pacific Ocean. Our results show that

Kelp forests are highly productive coastal habitats and are emerging as important sources of organic matter for other ecosystems. Although their high rates of productivity and detritus release are expected to lead to substantial export of carbon, few studies have actually quantified rates of export or the persistence of detritus. We addressed this in eight subtidal kelp forests (Laminaria hyperborea)

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L−1), and its subsets (2

Dam construction is widespread, changing the hydrological and biogeochemical conditions and thereby the bacterial communities in the rivers of the earth. To date, knowledge is lacking about bacterial communities in cascade reservoirs. Here, we investigated the bacterial communities and potential functions of nine cascade hydropower reservoirs in 1290 km of the upper Mekong River (Lancang River in China)

Fjords are recognized as hotspots of organic carbon (OC) burial in the coastal ocean. In fjords with glaciated catchments, glacier discharge carries large amounts of suspended matter. This sedimentary load includes OC from bedrock and terrigenous sources (modern vegetation, peat, soil deposits), which is either buried in the fjord or remineralized during export, acting as a potential source of CO2

Anthropogenic activities such as eutrophication and fishing have prominent effects on freshwater ecosystems. However, the ways in which ecosystem function and biodiversity respond to multiple drivers from eutrophication and top-down predation remains inconclusive. We studied zooplankton communities in 102 subtropical shallow lakes in the eastern plain of China and further examined the joint effects

Urea sinks are mainly associated with assimilation by phytoplankton. However, recent studies have shown that there is a process by which nitrifiers convert urea-derived nitrogen (urea-N) into nitrate. We examined these two processes in the shelf and off-shelf regions of the Arctic Ocean. Urea concentration was high near the bottom in the shelf region, while it was depleted throughout the water column

Global change impacts marine organisms and communities mainly through ocean warming, acidification, deoxygenation, and changes in nutrient inputs and water circulation. To assess the ecological impacts of global change, the effects of multiple interacting environmental drivers, including their fluctuations, should be tested at different levels of biological organization. In an outdoor mesocosm study

Relationships between sea urchins and noncrustose macroalgae are typically nonlinear, and an abrupt phase shift from a barren to a macroalgae-dominated state and vice versa happens when the sea urchin abundance exceeds a critical threshold. Here, we have used two mass mortality events as a natural experiment to study progressive changes and dynamics between these stable states. In 2009–2010 and 2018

Secondary production connects primary producers with higher-order consumers. The response of secondary production to seasonal variation in primary producers can influence trophic flows that underpin key ecosystem functions and services. Within the canopy-forming macroalgal meadows of Ningaloo Reef, Western Australia, we quantified the secondary production generated by Sargassum-associated epifauna

Seasonal variations in dissolved organic matter (DOM) fluxes from land to sea have been well documented in the Arctic, yet remarkably little is known about how DOM varies seasonally within Arctic coastal waters. This is particularly true for shallow inshore environments. Here we document seasonality of DOM in lagoons along the eastern Alaska Beaufort Sea coast during the spring ice break-up (June)

The Subantarctic Ocean is a sink for atmospheric CO2, largely due to its biological pump, which is enhanced by the influence of the Subantarctic islands on the plankton ecosystem (the so-called “island mass effect”). The influence of the Prince Edward Islands archipelago in the Indian Subantarctic on the surrounding hydrography and benthos has been well studied; however, over the last two decades,

The 18O/16O of precipitated silica in natural environments is posited to record the temperature of the ambient environment. Measurements of 17O/16O in silica (SiO2), when paired with 18O/16O, provide an opportunity to further constrain the environmental conditions at the time of mineral precipitation and ripening. On Cenozoic timescales, siliceous frustule precipitation by diatoms has served as the

Natural and human features on land result in differential loadings of carbon (C), nitrogen (N), and phosphorus (P) to rivers that influence within ecosystem processing. However, little is known about how land use, together with seasonal changes in climate and hydrology, influence the relative proportions of C, N, and P in rivers. To evaluate the spatial and temporal patterns in ecosystem-level C: N: P

Benthic animal populations inhabiting intertidal flats provide important ecosystem functions and services that may be disrupted by physical disturbances such as tropical cyclones, which are predicted to increase in frequency and intensity under future climate change. However, the spatial reach at which tropical cyclones impact macrobenthos populations in intertidal flats remains poorly understood.

Inorganic nutrient limitation affects the stoichiometry and nutritional quality of marine phytoplankton. Mixoplankton, able to photosynthesize and feed simultaneously in the one cell, can compensate shortage of nutrients by phagotrophy, theoretically upgrading their nutritional quality for their predators: the zooplankton. Yet, the additional value that phagotrophy in mixoplankton may provide to support

Marine heterotrophic flagellates (HFs) form a diverse and ecologically relevant functional group of bacterial grazers and nutrient remineralizers in oceanic waters. Despite playing a crucial role in marine biogeochemical cycles, there is still a lack of information on which specific taxa dominate HF assemblages and what are their patterns of distribution in a global context. In the present work, we

While it is well known that severe marine summer heatwaves can cause acute and dramatic die-offs of seagrass meadows, the effect of trans-seasonal warming and winter/spring heatwaves are yet poorly understood. This study simulated a 9-months warming scenario on the common seagrass Zostera marina from winter into summer, using outdoor mesocosms, which provided near-natural conditions. The relevance