Trophic interactions in the pelagic area of lakes and the opposing effects of fish feeding (top-down) and phytoplankton biomass (bottom-up) on zooplankton communities are central topics in limnology. We hypothesized that zooplankton size distributions should be a more sensitive approach to disentangle top-down and bottom-up effects than the commonly measured zooplankton biomass. We examined zooplankton

The interaction of various environmental triggers on phytoplankton communities of an artificial lagoon of Hangzhou Bay China, was studied during a Microcystis bloom in summer 2016. Forty-two phytoplankton genera (six phyla) were defined, with Bacillariophyta accounting for half of all phytoplankton genera. It was determined that Melosira, Chlorella, Cyclotella, Microcystis, Merismopedia, Anabaena and

Understanding the movement ecology of marine species is important for conservation management and monitoring their responses to environmental change. In this study, adult and subadult bull sharks (Carcharhinus leucas; n = 16) were acoustically tagged in Biscayne Bay, Florida (USA), where they were tracked locally via an array of 40 passive acoustic receivers, as well as regionally via cooperative acoustic

We studied feeding behavior and prey selection of topmouth gudgeon (Pseudorasbora parva), big-scale sand smelt (Atherina boyeri) and pike-perch (Sander lucioperca) in Lake Eğirdir, the second largest freshwater lake in Turkey. Fish specimens were collected between January and August in 2010 and 2011 using gill-nets and purse seines. A total of 941 specimens were analyzed for stomach contents analysis

Few studies have evaluated the effects of large wildfires on downstream non-salmonid fish assemblages. Using multi-year (2009–2015) data from fish assemblage surveys and high-frequency water quality monitoring, we analyzed within-site responses of a cypriniform-dominated fish assemblage at two sites located > 20 km downstream of a 633 km2 wildfire in 2011 in the Rio Grande watershed in New Mexico,

The constant entry of microplastics in several environmental matrices has been of great concern to the scientific community and to society in general, mainly due to the mysteries that surround the implications of this pollutant in the environment. Freshwater ecosystems are resources especially susceptible to variations in environmental quality, and the lack of data on the impacts caused by plastic

The Salado River basin, Buenos Aires, Argentina, contains numerous permanent shallow lakes under anthropic pressure due to different land uses/land covers (LULC) in their catchments. Here, we explored the relation of LULC in the surrounding areas and the physical and chemical variables of six shallow lakes of the aforementioned basin with phytoplankton structure and morpho-functional groups (MFGs)

Calcifying organisms such as benthic foraminifera are susceptible to changes in ocean pH and alkalinity. Responses to these changes include variations in mortality, calcification rates or assemblage composition, which have been observed in field and experimental studies. Here we applied a growth experiment with benthic foraminiferal propagules under different pH conditions to gather insights into the

Many aquatic plants are characterized by clonal growth through which the mother ramet can support offspring ramets by providing resources. The capacities of exploring space, sampling environment and overcoming establishment risks for offspring ramets could be enhanced with the resource support of the mother plant, which may change over time. This study aimed to investigate whether there is a change

The salinization of freshwaters due to the use of deicing road salts is a serious anthropogenic threat. We investigated the effects of the road deicer, which is mostly composed (ca. 70%) of NaCl, on the life cycle parameters of the cladoceran Moina macrocopa in acute and chronic toxicity tests and on the hatching success of resting eggs exposed to sediments contaminated with the road salt. The negative

Diaphanosoma s.l., with 40+ described species, is the largest genus of the Sididae and the Ctenopoda, similar in many ways to the anomopod genus Daphnia. Here, we offer a c morphological evaluation of 33 species and contrast it with an analysis of the bar coding fragment of the cytochrome c oxidase subunit (COI) gene in order to gain insight into the taxonomy and phylogeny of the group. A search for

Separating species in terms of dispersal capacity can be useful to understand how local and regional factors affect the distribution of organisms in metacommunities. In this study, we sought to unravel how the characteristics of local habitats and spatial distances structure fish communities in Amazonian streams. We hypothesized that fishes classified with high dispersal capacity are mainly structured

In freshwater ecosystems, macrophyte contribute to habitat heterogeneity with their varying structural forms, ranging from free submerged to rooted species. Macrophytes provide substrates that support fish populations, providing food and refuge from predators, especially in semi-lentic environments, like river floodplains, which tend to provide little shelter for small fish. We investigated how the

Multi-wavelength Chl a fluorometers are increasingly applied to assess phytoplankton photosynthetic capacity and composition, but their usefulness is limited by uncertainties in fluorescence excitation spectra (FES). We investigated this issue using the Phyto-PAM fluorometer to evaluate the effects of innate and irradiance-dependent variations in background (F) and variable (Fv) FES on analysis of

We analysed the relationship between functional and structural variables (leaf litter decomposition, biofilms growth, primary productivity, invertebrate communities’ taxonomic structure, and biological traits) and environmental conditions from headwaters into the estuary, which remains under-investigated. Six river sections (headwaters, middle reach, and four large river sections with increasing salinity)

Invertebrate species from temporary aquatic ecosystems produce resistant dormant stages (i.e. eggs) that accumulate in long lived mixed egg banks in the sediment. These dormant eggs not only bridge dry phases but also act as propagules for passive dispersal. Large branchiopod crustaceans (e.g. Notostraca, Anostraca and Spinicaudata) produce dormant eggs of variable shapes, sizes and external ornamentation

Our understanding of the ecological drivers that control community structure of benthic rotifers is poorly known. By reviewing 21 papers on freshwater benthic rotifers we compiled an inventory of an additional 258 species, 27 genera, and six families not previously listed in the review of benthic, lotic rotifers by Ricci and Balsamo (Freshw Biol 44:15–28, 2000). This raises the number of reported benthic

In ecology, interaction networks allow the investigation of how interactions among species affect community structure and functioning. The structure of interaction networks can be nested and/or modular. Ecologically, the nested structure minimizes competition and increases the number of coexisting species, creating high diversity, while the modular structure occurs when there are non-overlapping groups

Previous studies have shown that moderate concentrations of Chinese tallow leaf litter can quickly reduce dissolved oxygen and pH in the aquatic environment. While these studies mostly focus on its effects on the performance of amphibians, this study focuses on determining the causes of deoxygenation and acid water. We also examined the effects of Chinese tallow litter on other water quality parameters

Lake ecosystems contain numerous habitats, such as the relatively homogeneous pelagial, as well as many different subhabitats in the littoral zone. Among rotifer communities inhabiting the littoral zone are those living in organic sediments (epipelon), on submerged stones (epilithon), among sand grains (hydropsammon), on animals (epizoon), on submerged branches and twigs (epixylon) and on macrophytes

The diet of the kingfisher Alcedo atthis is usually studied by collecting pellet pools from the nest after breeding. This collecting method is very efficient but has some drawbacks which include invasiveness and restriction to the reproductive period. To overcome these limits, here we propose the collection of pellets under resting sites. Although requiring a large number of surveys to find suitable

Sexual reproduction can enhance the colonization and spread of invasive plants. We aimed to evaluate ecological factors influencing sexual reproduction and dispersal capacity of exotic Spartina taxa. Density of inflorescences, spikelets per inflorescence, percentage of spikelets with caryopses, and density of caryopses were recorded for North American S. patens, South American S. densiflora, and reciprocal

There is a consensus that human activities affect biodiversity in pond ecosystems. However, the majority of studies have mainly focused on the direct effect of human activities on a single group, despite the fact that anthropogenically induced biodiversity loss in ecosystems occurs across multiple trophic levels and may depend on both altered habitat (e.g., water chemistry) and on trophic interactions

Knowledge of turtle hatchling ecology is fundamental for managing wild populations. Information on habitat selection by turtle hatchlings is particularly important to ensure that conservation programmes that release hatchlings into the wild give them the best chances of surviving to adulthood. Currently, knowledge of the ecology of turtle hatchlings worldwide is limited, which restricts evidence-based

Although parasitism is one of the most prevalent interactions in nature, studies of aquatic food webs rarely include parasites. Syndiniales (Dinophyceae, Alveolata) is a diverse parasitic group of dinoflagellates, common in all marine environments, and are described as dominant components of pelagic ecosystems. However, their temporal dynamics, prevalence, and host-specificity are poorly known. Using

The occurrence and distribution of aquatic macrophytes within a wetland depends on the hydrological requirements of each species and the hydrological conditions. The aims of this study were to: (1) determine relationships between germination of Eleocharis acuta and Eleocharis sphacelata and hydrological regime, (2) determine the buoyancy of the seeds of E. acuta and E. sphacelata and hence their ability

European catfish Silurus glanis is a large non-native opportunistic predator able to develop hunting strategy in response to newly available prey where it has been introduced. Migrating spawning anadromous prey such as allis shad Alosa alosa could represent this available and energy-rich food resource. Here, we report an impressive catfish hunting behavior on shad spawning act in one of the main spawning

In aquatic systems, organisms largely rely on chemical cues to perceive information about the presence of predators or prey. Daphnia recognize the presence of the predatory larvae of Chaoborus via a chemical cue, emitted by the larvae, a so-called kairomone. Upon recognition, neckteeth, an alteration of the carapace, are induced in Daphnia that reduce predation rates of Chaoborus. Neckteeth induction

Due to climate change, water level fluctuations (WLFs) in shallow lakes are expected to increase in the future. Such fluctuations significantly affect the growth and reproduction of submerged macrophytes, but the role of WLF on plant physiological mechanisms is far from clear. Our aims are to examine the effects of WLF on the submerged macrophyte Vallisneria spinulosa by testing changes in (1) chloroplast

Antillean manatees in the Hondo River have been recorded from aerial and aquatic surveys, and interviews. However, these studies have been conducted only in the lower riverbed, leaving a gap of information about their presence and habitat characteristics in the rest of the river. We characterize and determine the ecohydrological variables influencing the presence and habitat use of manatees in the

Phospholipid (PL) composition has a tremendous influence on the cell integrity and physiological competency. At the same time, plankton PL make important metabolic fuels for higher trophic levels. The goal of this study was to identify environmental control on PL production and their molecular identity of the suspended particles in two different estuaries. We conducted research in subtropical, eutrophic

Diel vertical migration (DVM) is the most common behavioral phenomenon in zooplankton, and numerous studies have evaluated DVM under strong seasonality at higher latitudes. Yet, our understanding of the environmental drivers of DVM at low latitudes, where seasonal variation is less pronounced, remains limited. Therefore, we here examined patterns of vertical distribution in copepods in six subtropical

Man-made reservoirs are important freshwater ecosystems as they are globally common and share features of both standing and running waters. In streams and lakes, crayfish are an important component of freshwater ecosystems due to their habitat-modifying behaviour, substantial size, omnivorous feeding and often high abundance; however, their trophic role in reservoirs is not known. We evaluated the

Data collected on zooplankton community composition over longer time periods (> 10 years) are rare. We examined among-lake spatial and temporal trends of zooplankton communities from a monitoring programme undertaken in the Waikato region, New Zealand. A total of 39 lakes were sampled over a period of 12 years, between 2007 and 2019, with varying degrees of temporal effort. We focussed particularly

The effects of food availability on thermal stress in Daphnia magna were investigated for 21 days, with a hypothesis that lower food condition would increase the adverse effect of elevated temperature on D. magna. Under higher food conditions (5 × 105 cells mL−1), elevated temperature (25 °C) did not induce higher oxidative stress (levels of antioxidant enzymes and lipid peroxidation) than reference

Differences in elemental stoichiometry among consumers can regulate fundamental ecological processes such as animal production or nutrient cycling within ecosystems. Research to date has established that consumer stoichiometry differs within and across taxa, but the degree to which organismal stoichiometry ranges ontogenetically across life stages or body sizes is poorly understood. To understand patterns

Upper reaches of temperate streams and oligotrophic lakes depend trophically on the organic matter coming from the surrounding watershed. These aquatic ecosystems accumulate particulate and dissolved organic matter, and chemical compounds liberated from decomposing leaves or from the leachates of leaf litter. These materials supply a wide range of chemical compounds, which may serve as food, but also

Hydroperiod length has been identified as a major driver in community assembly in freshwater systems. Yet we generally lack an understanding of how morphological traits respond to water level decrease under natural conditions. Here, we studied variation in body size and shape in lateral view in tadpoles of Scinax squalirostris and Odontophrynus americanus inhabiting ponds in superhumid highland plateau

Dispersal is one of the main determinants of metacommunity assembly, yet its interaction with the landscape network structure has not been fully elucidated. Large-scale regional factors such as the centrality–isolation gradient influence community abundance and richness, but small-scale regional factors, such as the direction or the distance among water bodies, might also influence them. Furthermore

The establishment probability of introduced alien fish can be context dependent, varying according to factors including propagule pressure and biotic resistance. The influence of nutrient enrichment on establishment outcomes of alien fishes is uncertain, yet this is a common anthropogenic stressor of many freshwaters. Here, the small-bodied alien topmouth gudgeon Pseudorasbora parva was used in mesocosms

Meiofaunal organisms are the predominant metazoans in benthic systems and important members of the benthic food web. They are defined by mesh size and specifically by their retention on a sieve with a 44-µm mesh size. In this study, we examined the accuracy of this standard collection method by counting the number of meiobenthic individuals, life stages and nematode species in a sample. A filter cascade

Meiofaunal abundance, biomass and secondary production were investigated over 13 months in an unpolluted first-order stream. Four microhabitats were considered: sediment and the biofilms on dead wood, macrophytes and leaf litter. The relative contribution of the microhabitats to secondary production and the influence of environmental factors on meiofaunal density distribution were estimated. We expected

The ciliate–metazooplankton trophic coupling is well documented from both laboratory and field experiments. The knowledge about these relationships during winter ice-covered periods is very scarce. The abundance and composition of planktonic ciliates, rotifers and crustaceans were studied during the ice-covered and ice-free periods in the Łuczański Canal (Masurian Lakeland, Poland). We hypothesised

Light affects bivalve behavior and gaping activity, but its potential effects on bivalve filtration remain poorly investigated. In this study, clearance rates of two bivalve species: the Asian clam, Corbicula fluminea and the paper pondshell, Utterbackia imbecillis, were assessed in light (6.5 ± 0.5 µmol m−2 s−1) and dark (0.0 µmol m−2 s−1) conditions. We found that clearance rates remained similar

The aim of this review is to analyze the literature on the impact of beavers on lakes, summarize their effects, describe consequences for biotic and abiotic components, and highlight unresolved issues and perspectives. Beaver activity changes vegetation structure to the greatest extent, indirectly affecting other ecosystem components. Damming of flowing lakes increases the littoral area, which affects

Deforestation of riparian areas is a major driver of biodiversity loss in aquatic ecosystems. Thus, we investigated the influence of forest cover and physical and chemical characteristics of streams on zooplankton communities in the southeastern Amazon. We addressed the following questions: (1) Are environmental factors (water physical and chemical characteristics and landscape variables) and dispersive

The non-indigenous colonial tunicate Didemnum vexillum plagues many shellfish aquaculture operations around the world by smothering crop and gear and displacing juvenile bivalves. There are two populations of D. vexillum in Oregon, but little is known regarding their spatial extent, seasonal dynamics, annual variability, reproductive biology, or ecology. SCUBA divers monitored the seasonal variation

Environmental heterogeneity and productivity are factors driving beta diversity of freshwater communities. Further, characteristics as spatial extent and connectivity, as well as land use and cover, can determine local biodiversity patterns. We evaluated the correlates of within-lake beta diversity of phytoplankton communities in 25 coastal shallow lakes in southern Brazil. We hypothesize that within-lake

Marine macroalgae serve as habitats that provide ideal shelter for a rich and diverse community of associated molluscs, but the true effects of the complexity of these habitats on fauna are still poorly understood. Replicates of four macroalgal species: Gracilaria domingensis (Kützing) Sonder ex Dickie 1874, Solieria filiformis (Kützing) Gabrielson 1985, Gracilaria cuneata Sonder ex Kützing 1859 and

Shrimp aquaculture has caused broadscale shifts in mangrove ecosystems worldwide, including changes in habitats and functional traits of mangroves, to the point of widespread destruction in some countries. The propagule is an important stage in mangrove life history, reflecting the resource investment of parents and the ability of offspring to build a population. However, the impacts of shrimp aquaculture

River regulation has altered the seasonal timing of flows in many rivers worldwide, impacting the survival and growth of riparian plants. In south-eastern Australia, demand for irrigation water in summer often results in high river flows during a season that would naturally experience low flows. Although unseasonal high summer flows are thought to significantly impact waterways, their effects on vegetation

Salinity can compromise the growth of aquatic macrophytes, influencing their nutrient content and interspecific interactions. In estuaries, the sediment characteristics vary in salinity as well as nutrient availability, granulometry and microbiota. The use of artificial substrates in manipulative experiments allows the evaluation of the isolated effect of salinity on plants. We evaluated the effects

The common octopus Octopus vulgaris Cuvier, 1797, once considered a cosmopolitan species, is a species complex composed by six species: O. tetricus, O. cf tetricus and O. sinensis in the Pacific; type I and II, in the West Atlantic; and type III in the Indian Ocean around South Africa. The tropical western central Atlantic is an important octopus fishing ground targeting O. maya, O. insularis, and

Rivers are heterogeneous and patchy-structured systems in which regional biodiversity of aquatic communities typically varies as a function of local habitat conditions and spatial gradients. Understanding which environmental and spatial constraints shape the diversity and composition of benthic communities is therefore a pivotal challenge for basic and applied research in river ecology. In this study

Two subspecies of bottlenose dolphins are observed, not simultaneously, in a narrow coastal area of the western South Atlantic Ocean. However, their trophic interaction is unknown. Such information can be explored using stable isotope composition in teeth, warranting time series data. We analyzed carbon and nitrogen isotopic values (δ13C and δ15N) of dentin growth layer groups in teeth of Tursiops

Fish–habitat relationships are a key element for conservation and management strategies, especially in highly disturbed areas where fish communities are subjected to many human pressures. In this regard, multiscale studies help to improve the knowledge of the spatial components and identify local (e.g. water width) and regional (e.g. elevation) key variables in species distribution. We examined local

Lake littoral environments are heterogeneous, and different organisms typically show specific responses to this environmental variation. We examined local environmental and spatial factors affecting lake littoral biodiversity and the structuring of assemblages of phytoplankton, zooplankton and macroinvertebrates within and among three basins of a large lake system. We explored congruence of species

Many methods of controlling invasive crayfishes have limited success because they fail to target all life stages of the population, notably by capturing only large adults that can result in increased juvenile recruitment by removing intraspecific predation. An alternative approach uses the sterile male release technique that involves the mass release of sterile males into the environment, which then

We tested whether changes in water transparency caused either by precipitation-mediated sedimentation (inorganic turbidity) or eutrophication (organic turbidity) differently interact with top predator presence to determine predation rates, and individual decisions of mesopredators between foraging and avoiding predators. We tested the hypothesis that fear-induced cascade effects are more pronounced

Successful coexistence with predators depends on the ability of prey to strike a balance between the costs of predator avoidance and the benefits of foraging and reproducing as there is a trade-off between these activities. Prey animals can balance this trade-off by responding to predation risk in a manner that matches the intensity of risk posed by the predator, which is known as the threat-sensitive