How a population adapts to environmental changes is a central topic in ecology, but long-term changes in the phenotype of an organism have rarely been studied in aquatic systems. In this study, we examined the morphological changes in Daphnia pulex from the initial establishment stage, using paleolimnological analysis, in Lake Fukami-ike (Nagano Prefecture, Japan). We measured morphological traits

The differences between temperate and tropical seasonality suggest that ecological models developed for temperate streams do not necessarily apply to tropical streams. While detritus is the base of the temperate zone stream food webs, we expected a seasonal alternation in the energy source in tropical streams (i.e., increase in the autochthonous energy source in the dry season, and an increase in the

The lipid and fatty acid content of benthopelagic scavenging amphipods Ommatogammarus flavus and O. albinus from different depths of Lake Baikal were studied. These amphipods, known to move across a wide range of depths in Lake Baikal, had a relatively high level of total lipids (up to 46% dry weight) in comparison to other aquatic amphipods. This high level of total lipids resulted from a high concentration

Anthropogenic impacts have been reported as one of the main causes of eutrophication in freshwater systems and nutrient availability, mainly from discharges, are key to cyanobacteria development and harmful cyanobacteria blooms (cyanoHABs) upsurge. As these scenarios are common in the Azores, a cyanobacteria monitoring program was implemented in the lakes of the archipelago, which comprises cyanobacteria

The conversion of riparian vegetation into monocultures alters the input of allochthonous energy and the heterotrophy of streams. Here, we aimed to assess the implication of leaf litter inputs from plant species of agricultural importance on decomposition in Amazonian streams. We hypothesized that decomposition is low in litter with high concentrations of lignin and cellulose, regardless of the origin

Climate change is causing frequent and large floods, creating a need for information regarding the impact of severe flood disturbances on stream invertebrates. We briefly describe the response of invertebrate assemblages to an extreme flood event in 2018 in the western Ehime Prefecture of Japan. We compared invertebrate data collected in past regional-scale surveys with those gathered by revisiting

Vertical circulation reaches the bottom of the deepest (> 90 m) part of the northern basin of Lake Biwa, a warm monomictic lake, during winter (January to March) every year. In winter 2019, we found non-circulated water masses at the bottom of the lake where the basin is 90 m deep. This is the first observation of an incomplete vertical circulation event since we started monitoring Lake Biwa in 1979

Changes in river environments due to elevation gradients have a great impact on living organisms. In particular, with respect to aquatic insects, it has been recognized that even in closely related species there is a tendency for species to be replaced between upstream and downstream environments. Such a distribution tendency has also been suggested for the three species of the genus Ephemera of interest

Metacommunity structure of stream invertebrates is contingent on complex interplays between species dispersal ability, spatial extent and watershed environmental specificities. Previous studies showed that high diversity of Chironomidae (Insecta, Diptera) is observed in southern Brazilian montane streams, although the knowledge of the processes driving such high diversity is poorly comprehended. In

Dams disrupt the longitudinal gradient and decrease the natural connectivity of lotic systems and change the physical, chemical, and biological compartments of the river environment. Here, we investigated the effects of damming and seasonal variation in environmental conditions and richness, density, taxonomic and functional beta diversity patterns of phytoplankton, through dry and rainy seasons (of

In Lake Biwa, picocyanobacteria blooms usually occur during the summer–autumn thermal stratification period. Intriguingly, a novel bloom was detected in winter 2015–2016, in which picocyanobacterial cell density increased by one order of magnitude despite lower water temperature, suggesting the possibility that “cold-water-preference” species dominate in the picocyanobacterial community. In the present

Natural fluctuations in ecosystems, such as those associated with climate, are a fundamental factor structuring macroinvertebrate assemblages. Given that macroinvertebrates are widely used in biomonitoring of aquatic systems, it is necessary assess the potential effects of seasonality on this group to avoid confusing its effects with the effects of anthropogenic impacts. In the present study, the richness

Daphnia, keystone herbivores in lakes, routinely produce immediately hatching eggs; additionally, they also produce resting eggs enveloped by an ephippial case, a thickened carapace that allows population survival under harsh environmental conditions. To examine differences in ephippial morphology between Daphnia species in different subgenera, we conducted microscopic observations and genetic analyses

Blooms of green macroalgae (Ulva spp.) occur frequently in the hypereutrophic Yatsu tidal flat of eastern Japan. In this study, to elucidate the effects of such blooms on nutrients and sulfide dynamics, we measured Ulva nutrients uptakes and stocks, and sulfide release during Ulva blooms decay. NH4+ uptake was greater than NO3– uptake when NH4+ was sufficient, whereas NO3– uptake increased in the absence

In recent years, biodiversity loss has become one of the most serious environmental issues worldwide, especially in aquatic ecosystems. To avoid diversity loss, it is necessary to monitor biological communities, and environmental DNA (eDNA) metabarcoding has been developed as a rapid, noninvasive, and cost-effective method for aquatic biodiversity monitoring. Although this method has been applied to

Testate amoebae are an irreplaceable key component of microbial communities in many aquatic and soil ecosystems and well known as useful bioindicators. In the present work, testate amoebae compositions in different-type biotopes of freshwater waterbodies of North Vietnam were investigated for the first time. A total of 80 species and subspecies belonging to 12 genera and 8 families were identified

Although Cyclops vicinus Uljanin, 1875 and C. kikuchii Smirnov, 1932 are broadly distributed in Eurasia, the genetic divergences between European and Asian populations have been investigated in neither species. In Japan, the nomenclature and distinction between these two congeners are still questionable (thus, hereafter C. vicinus s.l.). We determined the taxonomic position of the Japanese C. vicinus

Understanding the role of abiotic and biotic factors on biological communities is a challenge for ecologists. Individuals of the order Odonata have a close connection with these factors, which can influence the establishment of each stages of live. This study evaluated the relationship between habitat complexity and limnological variables on the diversity of Libellulidae larvae and adults. Our hypotheses

Exotic species have invaded freshwater ecosystems, causing biodiversity loss of associated communities. We investigated the influence of the invasive macrophyte Hydrilla verticillata on taxonomic and functional richness, and on taxonomic and functional beta diversity of associated Chironomidae community, comparing this macrophyte with the structurally similar native macrophyte, Egeria najas. We conducted

Multi-proxy analysis of lake sediments provides high-resolution and reliable palaeoclimate records. The present study aims to investigate the palaeoenvironmental changes and eutrophic evolution of the Wular Lake, Kashmir Valley spanning the last ~ 500 years. Based on the multi-proxy analysis and supported by radiocarbon chronology, two prominent environmental phases were identified. From 74 to 45 cm

Spatial synchrony occurs when local populations exhibit correlated dynamics over time. Recent studies, both experimental and observational, have indicated that the magnitude of spatial synchrony, in cross-species analyses, is correlated with the level of specialization. In theory, specialist species would exhibit higher levels of synchrony than generalist species because they would be more sensitive

Insufficient knowledge about ecology of weed macrophytes from a large-scale perspective narrows the necessary decision-making for biodiversity conservation. The present study aimed to assess the occurrence frequency of Egeria densa in lotic and lentic/semi-lotic environments from a Brazilian dammed river, as well as to quantify the attributed explanation (pure or combined) by limnological and spatial

Estimating the presence and abundance of non-native species in the early stage of invasion is important to prevent further spread of non-native species in aquatic systems. Environmental DNA (eDNA) methods have been applied for aquatic plants; however, it is still questionable on the accuracy of the eDNA methods for the detection and abundance estimation of aquatic plants in lotic systems. Here, we

This study investigated temporal changes in the vertical distribution of invertebrates during periods of low flows in the Tafna wadi, a semi-arid Mediterranean river characterised by a general decline in average flows. The hyporheos was sampled along a 130-m stretch at depths of 0.3, 0.6 and 1 m in a pool-riffle sequence and a lateral gravel bar. Benthic fauna was collected on each sampling occasion

To examine how compositional changes in a community vary depending on time scales, we estimated temporal β-diversity of zooplankton in Lake Hataya Ohnuma, a small lake in Yamagata, Japan. The zooplankton community was monitored for 9 years with monthly samplings. We estimated the inter-annual, inter-seasonal, intra-seasonal, and inter-month β-diversity with the magnitude of sampling errors, and examined

Environmental DNA (eDNA) is an emerging approach for detecting species, yet numerous methodological questions remain unanswered. Here we examined how time to filtration (0–48 h after collection) and sample storage (open vs. chilled in the dark) influenced detection and measured eDNA concentration. Water samples kept in the dark and chilled had no significant decrease in detection or eDNA concentration

Optical water types (OWTs) can represent diverse ranges of Chlorophyll-a (Chl-a), total suspended matter (TSM), and colored dissolved organic matter (CDOM) concentrations, which make them extremely useful for monitoring water quality, for example, detecting eutrophic conditions or tuning remote sensing algorithms. In this study, the objective is to assess OWTs found in Brazilian waters using in situ

Cyanobacteria are the major producers of the taste and odour compounds geosmin and 2-methylisoborneol (2-MIB) in drinking water and fish worldwide. In recent years, the outbreaks of cyanobacteria blooms in Tri An and Dau Tieng Reservoirs, Vietnam have led to an increase attention in taste and odour problems. In the present study, the two off-flavour compounds geosmin and 2-MIB were found in field samples

The Cimanuk River with a total watershed area of 4010.8 km2 flowing from the Garut Regency to Indramayu Delta is the longest in West Java Province. However, the cumulative effects of climate change, increased population, and fish farming in the coastal area have continuously pressured the availability of water resources in its watershed. This study was, therefore, aimed to analyze the impact of land

A semi-enclosed river-mouth bay (Kojima Bay) and the artificial lake within it (Kojima Lake) were studied to examine their nutrient storage and export processes and characteristics. The aim of this study was to perform mass balance analysis using long-term monitoring and historical accumulation data of phosphorus (P) via 210Pb measurements of accumulated sediment. The results are then compared with

Phylloicus (Trichoptera, Calamoceratidae) is a stream invertebrate widely distributed across Neotropical biomes, which larvae use allochthonous leaf litter as food resource and to build a case that offers protection against predation. Seasonal changes in leaf litter accumulation on the streambed may affect Phylloicus larvae due to variations in availability of food and case-building material; however

Allochthonous organic matter in low-order streams is, in general, mainly composed of senescent leaves. However, in tropical streams green leaves can represent an important source of energy. The present study evaluated the decomposition of green and senescent leaves in Amazonian streams using leaves of three plant species: Inga stipularis D.C. 1876, Tococa guianensis Aubl. 1775 and Vochysia ferruginea

North African streams and rivers face multiple anthropogenic stressors, and their aquatic fauna is rapidly dwindling before comprehensive knowledge of their distribution and ecology has been attained. We investigated the distribution and life cycle of the Maghrebian endemic Ecdyonurus rothschildi Navás, 1929 in northeastern Algeria. The species was recorded both from permanent and intermittent freshwater

Northern ecosystems are experiencing rapid and large-scale changes driven by accelerated warming, which have profound effects on the terrestrial and freshwater biodiversity. A comprehensive understanding of the distribution of aquatic biodiversity of subarctic ecosystems is therefore needed to better predict future trajectories of their unique biodiversity. In this study, we examined the functional

The objective of this study was to develop a hydro-chemical model using the Soil and Water Assessment Tool (SWAT) and to evaluate the climate change impacts on discharge and nitrate-nitrogen loads from Ise Bay watersheds (the Kiso, Nagara, Ibi, and Shonai rivers). Using a regional climate model, through the dynamic downscaling approach, present and future climate data were generated at a 2 km spatial

Research on carbon gas flux to and from inland waters has increased over the past two decades, driven mainly by the need to understand (1) the global carbon budget in regard to stabilizing earth’s climate, and (2) how aquatic ecosystems and the services they provide change in response to anthropogenic pressures like climate and land use change. This paper reviews carbon flux research in support of

This study aims to confirm the effect of a small stream impoundment on phosphorus and nitrogen dynamics in a suburban watershed. The results show that the phosphate concentration in the water body was significantly higher than that in the inflowing water under ordinary flow conditions. The phosphorus promotes algal growth that causes significant diurnal dissolved oxygen variation because of photosynthesis

Controlling phosphorous (P) loads from rice fields is important for the conservation of aquatic ecosystems, in part because P is relatively concentrated at its sources. Recently, winter flooding, by which irrigation water is maintained in rice fields during winter, has attracted much attention as a farming strategy for environmental conservation and biodiversity maintenance. However, the effects of

A total of 24 soil samples, including 4 subsurface, 34 water samples and 17 sets of hydrological survey data were collected in a soil investigation and hydrological survey campaign from August 2017 to September 2018 at a small Dermawan forest catchment, Singapore. The study was to understand and evaluate the catchment’s soil and stream status through the assessment of elemental concentrations and their

In the original publication of the article the sentence under the heading “Primer and probe design” was published incorrectly. The correct sentence is given in this correction.

DNA barcoding has been actively used as a method for species identification, and it will become an increasingly important method in the future. However, DNA barcoding can occasionally encounter a major problem, namely “nuclear mitochondrial DNA pseudogenes (NUMTs)”. In this paper, we report the discovery of a pseudogene in the mitochondrial COI region from aquatic heteropterans. PCR with Folmer’s universal

Hermaphroditic individuals in the population of Chinese crucians [Carassius auratus (Linnaeus, 1758)] in Chany Lake (Western Siberia) were recorded during a water level regression phase between 2006 and 2014. This period was characterized by critical conditions affecting crucian spawning because of increasing water salinity and a wide amplitude of water temperature fluctuations in the shallow spawning

Water flow velocity is a strong environmental filter structuring benthic communities in lotic ecosystems. While many studies have determined its effect on the distribution and diversity patterns of insects, the role of water flow velocity on other groups of aquatic invertebrates (i.e., Oligochaeta) has remained unexplored. We sampled five lotic ecosystems to investigate the influence of water flow

Eutrophication still is one of the greatest anthropogenic impacts affecting aquatic ecosystems. Food web manipulations to reverse eutrophic conditions have been applied, mainly by reducing fish stocks. However, the long-term results of biomanipulation are still ambiguous. The objective of this study was to evaluate biomanipulation effects on zooplankton functional diversity and production during 24 years

Effects of applying composted aquatic plants on soil chemistry, soil microbes (fungi and bacteria), and the growth of cultivated plant were demonstrated. To identify drivers promoting cultivated plant growth on soil amended with composted aquatic plant, empirical data of pot experiments were incorporated into structural equation models by hypothesizing causal relationships between the application of

Aquatic macroinvertebrate communities are dependent on intrinsic environmental characteristics and biological interactions in microhabitat systems. We investigated the species–area relationships, detritus content input and trophic interactions of macroinvertebrate fauna in 46 Vrieseae friburguensis in a “Restinga” environment. Our hypotheses are that (i) bromeliad water volume and detritus content

The in-stream processing of nutrients plays an important role in the fluvial nutrient transport from lands to the ocean, but few empirical studies have addressed the temporal dynamics of net nutrient removal rates in large river systems. The present study applied the recently developed Lagrangian approach to the sixth-order Fuji River to identify the seasonal dynamics of in-stream uptake rates for

We compared the oxygen isotope ratio of dissolved phosphate \(\left( {\delta^{{{18}}} {\text{O}}_{{{\text{PO}}_{{4}} }} } \right)\) in two rivers with different land-cover and geological features (Ado River and Yasu River) within Lake Biwa basin, central Japan, to explore what factor primarily characterizes the \(\delta^{{{18}}} {\text{O}}_{{{\text{PO}}_{{4}} }}\). Mean values of \(\delta^{{{18}}}

Ecological processes, population dynamics and species interactions in shallow lakes and reservoirs are affected by seasonal and inter-annual fluctuations in rainfall and runoff. The present study aimed to explore the relationship between riverine runoff and phytoplankton community structure in Koka Reservoir, Ethiopia. Onsite measurements and collection of water samples and phytoplankton were performed

We grew leaves of Montrichardia arborescens in four microcosm chambers with different temperatures and CO2 concentrations simulating the scenarios of expected climate change. These leaves were used to feed shredders (Phylloicus) and to assess the effects of changes in leaf quality on their consumption. We also evaluated the effect of detritus conditioning by microorganisms on leaf consumption. We hypothesized

The golden mussel (Limnoperna fortunei) has caused worldwide problems for the eco-environment and man-made structures. There have been many control strategies proposed, which have various strengths and weaknesses. To help selection of the effective control strategies that consider the biological traits of L. fortunei and the actual situation of biofouling, we studied the ecological amplitudes that

Controlling phosphorus is fundamental to limit the risk of eutrophication of continental aquatic ecosystems. Integrated modelling of its concentration in the aquatic continuum requires specific tools for water bodies. However, although simple static empirical models and complex biogeochemical models are numerous, there are few relatively simple and flexible models able to simulate seasonal variations

Eutrophication of lakes is one of the most common pressures affecting aquatic biodiversity and ecosystem services. Poyang Lake is of great importance for maintaining regional ecological balance; however, algal blooms have become major environmental problems in this basin, and they are also caused by a variety of problems including biodiversity decline, toxin production and possibly unsafe drinking

Extreme climatic events, such as flooding and drought, can abruptly modify the amplitude of the river level of a river, promoting new environmental conditions and impacting aquatic communities. Furthermore, an increasing frequency of extreme droughts in dammed rivers is expected because dams homogenize the flood pulse and decrease the river level. In this study, we evaluated the effects of extreme

Highly concentrated dissolved silicate was detected in pore water from anoxic-reducing sediment in Lake Nakaumi, a brackish lake. Silicate concentration also simultaneously increased with total hydrogen sulfide concentration during the summer. Generally, dissolved silicate is readily adsorbed onto ferric hydroxide and precipitates in an oxidative environment. In this study, we focused on the behavior

Morphology-based identification and classification of sponge species is complicated, because their morphological features are highly variable. Therefore, molecular markers are ideal tools for delimiting sponge species. In this study, we compared the variability of two sections of COI (the standard 5′-end fragment and the I3-M11 fragment) for closely related Baikal sponge species. Although the mean

To determine the potential long-term risks associated with continual use of pesticides, we investigated (1) whether short-term exposure (48 h) of first generation (1G) Scapholeberis kingi to two acetylcholinesterase-inhibitor insecticides, pyraclofos and pirimicarb, would alter acetylcholinesterase-inhibitor sensitivity (based on immobility) in the second generation (2G), (2) whether acetylcholinesterase

Physical processes associated with hypoxia events in a shallow lake, Lake Kasumigaura, Japan, are investigated with long-term mooring observations at the middle of the lake basin. Results show that strong stratification during the summer suppresses vertical mixing resulting in hypoxia in the bottom boundary layer. The dissolved oxygen decreases due to the limited oxygen supply under strongly stratified

The purpose of this study was to estimate the genetic distance, diversity and relationship of two large groups of Malawian cichlid, ‘mbuna’ living in rocky area and feeding on algae, and ‘non-mbuna’ in sandy area feeding on various items. A total of 78 species from 42 genera was determined for the DNA sequence of the mitochondrial control region. In a genetic tree, constructed with Kimura-2 parameter

Contrary to a general rule of stable isotope trophic discrimination, parasites show great variation in isotope discrimination from their host muscle tissues. One of the possible mechanisms is that isotopic variation among host tissues may cause apparent deviation from the actual isotope discrimination between a parasite and a given host tissue consumed by the parasite. To test this possibility, we