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Spatially explicit, near real time information on surface water dynamics is critical for understanding changes in water resources, and for long-term water security planning. The distribution of surface water across the African continent since 1984 and updated as every new Landsat scene becomes available is presented here, and validated for the continent for the first time. We applied the Water Observations from Space (WOfS) algorithm, developed and well-tested in Australia, to every Landsat scene acquired over Africa since the mid 1980s to provide spatial information on surface water dynamics over the past 30+ years. We assessed the accuracy of WOfS using aerial and satellite imagery. Four regional geospatial organisations, coordinated through the Digital Earth Africa Product Development Task Team, conducted the validation campaign and provided both the regional expertise and experience required for a continental-scale validation effort. We assessed whether the point was wet, dry, or cloud covered, for each of the 12 months in 2018, resulting in 34,800 labelled observations. As waterbodies larger than 100 km² are easy to identify with Landsat resolution data and can thus boost accuracy, these were masked out. The resulting overall accuracy of the water classification was 82%. WOfS in Africa is expected to be used by ministries and departments of agriculture and water across the continent, by international organisations, academia, and the private sector. A large-scale collaborative effort, which included regional and technical skills spanning two continents was required to create a service that is regionally accurate and is both hosted on, and implemented operationally from, the African continent. [ABSTRACT FROM AUTHOR]

Changes in fish species composition in the principal rivers of the Ararat Plain have been assessed over the last century through an analysis of the literature and field studies. A total of 39 fish species, spread across 12 families and 31 genera, have been documented across the Ararat Plain (Araks River basin within southern Armenia and northeast Turkey). In the Armenian section of the plain, 37 taxa have been recorded, including 12 non-native species. Over the past century, the number of fish species in the Metsamor River has increased from 15 to 23, and from 6 to 23 in the Hrazdan River. Currently 16 of the 21 native fish species, previously recorded, are still present in water bodies of the Armenian part of the plain. Rhinogobius cf. similis has been documented for the first time in this region. The primary reasons for the changes in the ichthyofauna composition in the Armenian part of the Ararat Plain are the introduction and subsequent spread of non-native species into reservoirs. This process involves species such as Rhodeus amarus, Knipowitschia caucasica, species of Gobio and invasive non-native species such as Pseudorasbora parva, Carassius gibelio, Rhinogobius lindbergi, R.cf. similis, and Oncorhynchus mykiss. [ABSTRACT FROM AUTHOR]

Spatially explicit, near real time information on surface water dynamics is critical for understanding changes in water resources, and for long-term water security planning. The distribution of surface water across the African continent since 1984 and updated as every new Landsat scene becomes available is presented here, and validated for the continent for the first time. We applied the Water Observations from Space (WOfS) algorithm, developed and well-tested in Australia, to every Landsat scene acquired over Africa since the mid 1980s to provide spatial information on surface water dynamics over the past 30+ years. We assessed the accuracy of WOfS using aerial and satellite imagery. Four regional geospatial organisations, coordinated through the Digital Earth Africa Product Development Task Team, conducted the validation campaign and provided both the regional expertise and experience required for a continental-scale validation effort. We assessed whether the point was wet, dry, or cloud covered, for each of the 12 months in 2018, resulting in 34,800 labelled observations. As waterbodies larger than 100 km2 are easy to identify with Landsat resolution data and can thus boost accuracy, these were masked out. The resulting overall accuracy of the water classification was 82%. WOfS in Africa is expected to be used by ministries and departments of agriculture and water across the continent, by international organisations, academia, and the private sector. A large-scale collaborative effort, which included regional and technical skills spanning two continents was required to create a service that is regionally accurate and is both hosted on, and implemented operationally from, the African continent.

In recent decades, severe climate change, decreased precipitation, temperature rise, and increased evapotranspiration (ET) have significantly reduced waterbodies. Furthermore, governments have prioritized the study of water level fluctuations of lakes to protect them from degradation nationally and regionally. The present study investigated the physical changes in lakes Bakhtegan and Tashk due to climatic parameters. To this end, Landsat satellite imagery and the NDWI were employed to calculate the area of the waterbodies from 1986 to 2018. The results showed that the area had decreased during the study period-- since 2009, Lake Bakhtegan had dried up completely. In 2008 and 2010, the lowest precipitation was 127.82 and 107.7 mm, respectively. During the study period (1986 to 2018), the average temperature was 19.44 °C, with an increase of 0.6 °C. Among the climatic parameters, precipitation, with a correlation coefficient of 0.55, and potential evapotranspiration (PET), with a correlation coefficient of about −0.68, were more strongly correlated with changes in the area of the waterbodies. To predict temperature and precipitation in the study area in the coming decades (2020–2050), the HadCM2 model of the CORDEX Project -WAS (South Asia) was used under two scenarios: RCP4.5 and RCP8.5. These scenarios revealed the decrease in precipitation and increase in temperature trends. As a result, the waterbodies’ areas were estimated using the projected precipitation and PET for the period 2050–2020, indicating a decrease in the areas of the waterbodies.

In recent decades, severe climate change, decreased precipitation, temperature rise, and increased evapotranspiration (ET) have significantly reduced waterbodies. Furthermore, governments have prioritized the study of water level fluctuations of lakes to protect them from degradation nationally and regionally. The present study investigated the physical changes in lakes Bakhtegan and Tashk due to climatic parameters. To this end, Landsat satellite imagery and the NDWI were employed to calculate the area of the waterbodies from 1986 to 2018. The results showed that the area had decreased during the study period-- since 2009, Lake Bakhtegan had dried up completely. In 2008 and 2010, the lowest precipitation was 127.82 and 107.7 mm, respectively. During the study period (1986 to 2018), the average temperature was 19.44 °C, with an increase of 0.6 °C. Among the climatic parameters, precipitation, with a correlation coefficient of 0.55, and potential evapotranspiration (PET), with a correlation coefficient of about −0.68, were more strongly correlated with changes in the area of the waterbodies. To predict temperature and precipitation in the study area in the coming decades (2020–2050), the HadCM2 model of the CORDEX Project -WAS (South Asia) was used under two scenarios: RCP4.5 and RCP8.5. These scenarios revealed the decrease in precipitation and increase in temperature trends. As a result, the waterbodies' areas were estimated using the projected precipitation and PET for the period 2050–2020, indicating a decrease in the areas of the waterbodies. [ABSTRACT FROM AUTHOR]

Landscapes are essential to human life: they provide a multitude of material (food, water, pollination) and nonmaterial (beauty, tranquility, recreation) values. Their importance is enshrined in international conventions and treaties, committing signatories to protecting, monitoring, and managing all landscapes. Yet, relatively little is known about how people conceptualize "landscape" and its constituents. There is emerging evidence that conceptualizations of landscape entities may influence landscape management. This in turn raises the question as to how people speaking different languages, and with differing levels of expertise, may differ in conceptualizing landscape domains as a whole. In this paper, we investigated how people conceptualize landscape‐related terms in a specific domain—waterbodies—by comparing German and English‐speaking experts and nonexperts. We identified commonly used waterbody terms in sustainability discourses in both languages, and used those terms to collect sensory, motor, and affective ratings from participants. Speakers of all groups appear to conceptualize the domain of waterbody terms in comparable ways. Nevertheless, we uncovered subtle differences across languages for nonexperts. For example, there were differences in which waterbodies were associated with calm happiness in each language. In addition, olfaction seemingly plays a role in English speakers' conceptualization of waterbodies, but not German speakers. Taken together, this suggests the ways in which people relate to landscape although shared in many respects may also be shaped in part by their specific language and culture. We collected sensory, motor, and affective norm ratings for waterbody terms in English and German. Broadly, speakers of both languages conceptualize the domains similarly; however, there were differences in the ways in which waterbodies were associated with calm happiness. [ABSTRACT FROM AUTHOR]

Featured Application: Nitrate pollution in waterbodies is a topic of environmental and health concern. Being aware of the wide range of technologies available is a challenge of real interest that will facilitate the selection of an eco-friendly and affordable water treatment technology in terms of equipment investment and energy costs. Nitrate (NO3−) pollution of surface and groundwater bodies is a global problem of increasing concern, which has stimulated significant research interest. Nitrogen is crucial for life as a macronutrient for living organisms on Earth, but the global nitrogen cycle has been seriously altered by intensification of human activities, leading to eutrophication and hypoxic conditions of aquatic ecosystems. Due to nitrogen overfertilization, intensive agricultural practices generate huge nitrate fluxes that inadvertently deteriorate water quality. Different industrial processes also contribute to NO3− pollution in the environment. There are multiple technologies capable of achieving effective denitrification of waterbodies to ensure safe NO3− levels. Either separation-based or transformation-based denitrification technologies must address the challenges of by-product generation, increased energy demand, and reduced environmental footprint. This paper highlights the most used approaches, along with some promising alternatives for remediation of nitrate-polluted waters. [ABSTRACT FROM AUTHOR]

Bathymetry of an open waterbody can be estimated remotely using airborne and space-borne sensors with wide coverage. However, unmanned aerial vehicle (UAV)-borne bathymetric systems are current trends for applications with limited depth subjected to the quality of water. Estimation of accurate bathymetry using surfacebased sensors is essential for validating the remote sensing-derived results. To cater to the requirements of the in situ measurement system, especially for supporting the airborne (aircraft/UAVs) remote sensing-based bathymetry systems, a customized and compact, immersion-type bathymetry system using single-frequency (typ. 500 kHz) transducer was developed in-house at the National Remote Sensing Centre (NRSC), ISRO, Hyderabad. In the present study, we assess the performance of the developed system in the field against physical measurements and a reference acoustic transducer for shallow and deep inland open waterbodies. Performance testing was carried out in the Asan Lake, a shallow waterbody, with a depth of up to 4 m and in the Tehri reservoir for deep bathymetry with a depth of more than 150 m. The results show that the estimated TVU for the developed system during shallow bathymetry assessment was 0.272 m which complies with the IHO order 1. The observed performance of the developed system was consistent with the system specifications, which advocate its utility for hydrology and water resource management applications along with its intended use to support remote sensingbased bathymetric systems. [ABSTRACT FROM AUTHOR]

Arctic lowlands are characterized by large numbers of small waterbodies, which are known to affect surface energy budgets and the global carbon cycle. Statistical analysis of their size distributions has been hindered by the shortage of observations at sufficiently high spatial resolutions. This situation has now changed with the high-resolution (

Arctic lowlands are characterized by large numbers of small waterbodies, which are known to affect surface energy budgets and the global carbon cycle. Statistical analysis of their size distributions has been hindered by the shortage of observations at sufficiently high spatial resolutions. This situation has now changed with the high-resolution (

In addition to religious content layers, the word hiis (holy grove) seems to express also certain features of a natural landscape. The article discusses the issues concerned with the location of hiis areas as well as their meaning. There are signs of links between ‘holy’ and ‘hiis’ that can be traced in the toponymy observed in both lore and maps, although it is not always that place lore or placenames have survived in written form until today. The main emphasis in the article is placed on the water element related to holy groves, waterbodies and springs as well as wetlands. Often the holy grove is situated at a watershed or headspring, next to springs, the mouth of a river or a stream, a (former) larger waterbody or karst area. Water connects many places, and holy places can often be found in the marginal areas or junctions of waterbodies. In the case of water and presumably also holy places, place lore seems to consider as essential the ability to move in different ways and change the shape – this is reflected, for example, in legends about travelling nature objects as indicators of holiness. On occasion, the hiis areas mark natural reservoirs of clean groundwater; this is essential to acknowledge as the issue of water still occupies a crucial role among other environmental problems. So the stereotype of hiis as a holy grove, so-called Taara oak grove, embodies remarkably broader possibilities for interpreting the holiness of places in today’s context, for valuing these places and protecting them both culturally and environmentally.

Understanding the role of street network configuration on commuter cycling can aid city planners in assessing and evaluating interventions to promote regular cycling into people's routines. Studies examining this relationship generally build models on observed cycling counts. While this provides valuable information, it could still result in an incomplete picture because some routes with advantages (e.g., good accessibility, amenities etc) may not have been utilised as expected because of other confounding factors (e.g., safety issues, motorised traffic) or vice-versa, leading to incorrect conclusions especially in the absence of data on these confounding factors. Thus, in this study, we argue that observing higher cycling flows on a route should not be the sole criteria to examine the role of street network configuration on the cycling patterns, especially when certain confounding factors have not been controlled for. We utilise data from the activity tracking app Strava for the city of Glasgow and compare the observed cycling intensities with the modelled cycling intensities where all the cyclists take the shortest routes. We estimated three linear regression models for: Observed Strava Cycling Intensities, Modelled Strava Cycling Intensities, and the difference between these two measures. Street network configuration were incorporated using Space Syntax measures: Normalised Angular Choice and Normalised Angular Integration. The roles of these variables, along with route characteristics and natural environment factors, on commuter cyclists' trips are explored. Visual exploration and linear regression models indicate that cyclists deviated away from the well-integrated, straighter routes to aesthetically attractive routes with cycling infrastructure, and towards links within mixed land use and to the least deprived areas. These results are of interest to policy makers and assist in infrastructure planning. [ABSTRACT FROM AUTHOR]

Campylobacteriosis is one among the leading causes of bacterial gastroenteritis worldwide. The present study was undertaken to evaluate the occurrence of Campylobacter spp. in water bodies in central Kerala by conventional plating technique using Blood-free campylobacter broth and modified Charcoal Cefoperazone Deoxycholate agar in combination with multiplex polymerase chain reaction (mPCR). The influence of physicochemical parameters of water like pH, conductivity, temperature, total dissolved solids (TDS), salinity, resistivity, dissolved oxygen and hardness on this organism was also evaluated. Campylobacter spp. was detected in 54.76, 16.67, 6.67, 6.67, 30.0 and 10.0 per cents of streams/rivers (42), ponds (30), lakes (30), wells (30), brackish waters (30) and seawater (coastal-15 and deep-15), respectively, by direct mPCR of broth enriched samples. The predominant species was Campylobacter jejuni, followed by Campylobacter coli in rivers/streams. This study revealed a higher degree of turbidity in river/stream, hardness in pond water as well as resistivity, electrical conductivity and TDS in brackish waters and higher electrical conductivity in seawater, which are usually less conducive for survival of the organism. An alkaline pH in lake water favoured the survival of the organism. Campylobacter spp. in water bodies indicate that these can act as possible sources for transmission of food-borne campylobacteriosis. [ABSTRACT FROM AUTHOR]

In Côte d'Ivoire, rubber cultivation has more than doubled since 2010. These mass agricultural areas require a large workforce with little information on how this environment might impact risk of mosquito-borne diseases. The objective of this study was to assess the larval ecology of mosquitoes in rubber areas of Dabou, Côte d'Ivoire. From January to June 2017, an entomological survey was conducted of mature (MP) and immature (IP) rubber plantations, as well as in villages surrounded by rubber plantations (SV) and remote from rubber plantations (RV). The number and type of potential and positive breeding sites were recorded, and mosquito larval densities and diversity were estimated. Seven genera divided into 31 species including major vector such as Anopheles gambiae s.l. and Aedes aegypti were identified. A total of 1,660 waterbodies were identified with a larvae positivity rate of 63.1%. A majority of waterbodies were identified in SV (N = 875, 53.4% positivity rate), followed by MP (N = 422, 81.8% positivity rate), IP (N = 194, 72.2% positivity rate) and least in RV (N = 169, 57.4% positivity rate). The most important breeding sites for disease vectors were leaf axils in IP (N = 108, 77.1%), latex collection cups in MP (N = 332, 96.2%) and the containers abandoned in the SV (N = 242, 51.8%) as well as in the RV (N = 59, 60.8%). All these results allow us to affirm that the cultivation of rubber trees has an impact on the larval ecology by increasing the number of available sites and favoring a high larval density and diversity. [ABSTRACT FROM AUTHOR]

Underwater optical wireless communication (UOWC) is an emerging technology designed to enable advanced high data rate applications, such as environmental monitoring, underwater exploration, and secure communication for military and defense purposes. Accordingly, a high-capacity UOWC system utilizing dual-polarization states and 16-quadrature amplitude modulation with orthogonal frequency-division multiplexing is proposed. The system leverages a single laser diode operating at 532 nm to generate orthogonally polarized signals that are transmitted along the X and Y polarization axes, achieving an independent data rate of 40 Gbps per polarization state with a total capacity of 80 Gbps. The performance of the proposed system is evaluated through the bit error rate (BER), error vector magnitude (EVM), and constellation diagrams for 10 distinct waterbodies. The findings demonstrate that water types with lower attenuation, such as pure water, Jerlov I, clear ocean, and Jerlov IA, enable longer transmission distances of 13.93, 13, 10, and 10 m, respectively, at a BER below the threshold limit (3.8×10−3) and an EVM of less than 16%. Conversely, higher attenuation in Harbor I and Jerlov III waters leads to shorter achievable ranges of 3 m at the same BER and EVM values. [ABSTRACT FROM AUTHOR]

Nitrate (NO3−) pollution of surface and groundwater bodies is a global problem of increasing concern, which has stimulated significant research interest. Nitrogen is crucial for life as a macronutrient for living organisms on Earth, but the global nitrogen cycle has been seriously altered by intensification of human activities, leading to eutrophication and hypoxic conditions of aquatic ecosystems. Due to nitrogen overfertilization, intensive agricultural practices generate huge nitrate fluxes that inadvertently deteriorate water quality. Different industrial processes also contribute to NO3− pollution in the environment. There are multiple technologies capable of achieving effective denitrification of waterbodies to ensure safe NO3− levels. Either separation-based or transformation-based denitrification technologies must address the challenges of by-product generation, increased energy demand, and reduced environmental footprint. This paper highlights the most used approaches, along with some promising alternatives for remediation of nitrate-polluted waters.

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The Tatun Volcanic Group (TVG), located in northern Taiwan, is characterized by acidic hot springs where the outflow of the hot springs may affect the properties of the associated lotic water bodies. We investigated the bacterial diversity and functional profiles of the Peihuang (PHC), HuangGang (HGC), and Nanhuang Creeks (NHC) located in the TVG basin using 16S rRNA gene sequencing coupled with statistical analyses. Water samples were collected from various streams of the creeks for two months of the year. The NHC showed the highest diversity, richness, and a unique number of phyla, which was followed by the HGC. A reduced number of phyla and a lower diversity was noticed in the PHC. The NHC was found to be abundant in the genera Armatimonas, Prosthecobacter, Pirellula, and Bdellovibrio, whereas the HGC was rich in Thiomonas, Acidiphilium, Prevotella, Acidocella, Acidithiobacillus, and Metallibacterium. The PHC was abundant in Thiomonsa, Legionella, Acidocella, and Sulfuriferula. The samples did not show any strong seasonal variations with the bacterial diversity and abundance; however, the relative abundance of each sampling site varied within the sampling months. The iron transport protein- and the sulfur metabolism-related pathways were predicted to be the key functions in all the creeks, whereas the heavy metal-related functions, such as the cobalt/nickel transport protein and the cobalt–zinc–cadmium efflux system were found to be abundant in the HGC and PHC, respectively. The abundance of Bdellovibrio in the NHC, Diplorickettsia in the HGC, and Legionella in the PHC samples indicated a higher anthropogenic impact over the creek water quality. This study provides the data to understand the distinct bacterial community structure, as well as the functional potentials of the three major watersheds, and helps the knowledge of the impact of the physicochemical properties of the TVG hot springs upon the watersheds. [ABSTRACT FROM AUTHOR]

This work reported the development, prototyping and validation of a low-cost colorimetric paper-based sensor for the analysis of phenolic contaminants in waterbodies. The device was constructed using chromatographic paper and the chromogenic probe was Folin Ciocalteu reagent. Results evidenced that undiluted chromogen solution and 15% sodium carbonate allowed the maximum performance of the sensor, which exhibited adequate linearity between 100 mg l−1 and 1000 mg l−1 and limits of detection and quantification of 25 and 1000 mg l−1, respectively for the phenolic probes herein used (e.g. gallic acid, catechol, pyrogallol and vanillin), as well as adequate recovery for gallic acid upon recovery test. Moreover, the paper-based sensor was used to evaluate a real sample, and results were compared to a standard test, thereby presenting no statistically significant difference (i.e. 505.21 mg l−1 for the standard test and 517.49 mg l−1 for the paper-based sensor, p > 0.05). The findings therefore suggests that the biosensor herein described is a low-cost and valuable alternative to detect and quantify phenolic contaminants in waterbodies.

The extent of surface-water spread influences the hydrogeology and ecology of waterbodies. Remote sensing technology provides spatial and temporal datasets which aid in mapping the dynamics of surface waterbodies at the regional and global scale. In the present study, temporal changes in the surface area of waterbodies in Telangana, India, were monitored using indices like normalized difference vegetation index, normalized difference water index and modified NDWI and machine learning algorithms like a random forest using Landsat-8 data. Google Earth Engine cloud computing platform was used for processing earth observation data, based on the time series images of Landsat and compared with real-time groundwater levels. The results showed a significant increase (P < 0.01) in both surface-water area and groundwater levels in Telangana, especially after 2015, which we hypothesize could be due to the specialized water conservation project being implemented by the Government of Telangana since 2015. [ABSTRACT FROM AUTHOR]

Ponds are among the world's most endangered freshwater ecosystems. A comprehensive knowledge of pond biodiversity is urgently required to inform effective pond management and conservation actions. Most studies about pond biodiversity focus on aquatic taxa, while the terrestrial biodiversity, especially of birds, has been little studied. Moreover, the few studies existing on pond biodiversity do not account for different detection rates of species, thus yielding biased results. Here, we apply a hierarchical Bayesian modelling technique to data obtained from visual censuses to estimate bird species richness associated with small ponds in a semiarid region, considering the imperfect detection of species. The model incorporates specific responses to site characteristics (pond typology), landscape (environmental heterogeneity) and at regional scale (mean annual precipitation). The studied ponds were used by two thirds of the terrestrial breeding bird community of the study region. Our modelling approach increased by an average of 7.5 species the observed site-specific richness. Drinking troughs supported a greater richness than other pond types. Environmental heterogeneity was positively related with species richness, whereas no clear relation was observed between richness and precipitation. In addition to ecosystem services provided by ponds to human welfare, our results suggest these small isolated habitats may act as key landscape elements for terrestrial birds in semiarid regions. [ABSTRACT FROM AUTHOR]

Anthropogenic activities causing a transformation of the natural nitrogen and phosphorus cycle are considered as one of the most fundamental environmental issues. In this study, nitrate and phosphate concentrations in waterbodies such as Abadaba river, Agulu lake, Njaba river, Oguta Lake, and Nike Lake located in Southeast, Nigeria was determined in both dry and wet season by spectrophotometric technique and modeled for pollution and health risks assessment. Result revealed that nitrate ranged from 13.163±2.30 mg/L at Nike to 36.173±7.22 mg/L Oguta lake in dry season while in the wet season it ranged from 17.402±3.459 mg/L at Abadaba to 26.748±6.536 mg/L at Njaba river. Phosphate ranged from 2.144±0.513 mg/L at Nike to 9.741±3.207 mg/L at Oguta in dry season while from 36.330±7.420 mg/L at Abadaba to 40.204±6.024 mg/L at Oguta. Comparing results with World Health Organization (WHO) allowed limits, it revealed that nitrate was low while phosphate was only low in the dry season at Abadaba, Agulu and Oguta lake. The waterbodies showed low variations (< 20 %) with positive linear relationships (R2 ≥ 0.3) for both nitrate and phosphate in both dry and wet season. Furthermore, except at Abadaba and Agulu in the dry/wet season and Njaba and Oguta in wet season, which showed no significant differences (p > 0.05) between them, all other showed significant difference (p < 0.05) for nitrate and phosphate concentrations. In terms of season, only at Njaba (for phosphate only) showed no significant differences (p > 0.05), all others waterbodies showed significant differences (p < 0.05) in nitrate and phosphate concentration in both seasons. The nitrate to phosphate ratio was very low especially in the wet season due to the high input of phosphate. The nutrient pollution index showed moderate to very high pollution while the waterbodies will pose very high non-carcinogenic health risks to users via the oral pathway. Overall, the waterbodies are at risk of eutrophication and efforts should be put in place to reduce anthropogenic activities around the area and thus input of nutrients in these water bodies.

Helminth infracommunities were studied at 174 sites of Latvia in seven hosts from six amphibian taxa of different taxonomical, ontogenic and ecological groups. They were described using a standard set of parasitological parameters, compared by ecological indices and linear discriminant analysis. Their species associations were identified by Kendall's rank correlation, but relationships with host size and waterbody area were analysed by zero-inflated Poisson and zero-inflated negative binomial regressions. The richest communities (25 species) were found in post-metamorphic semi-aquatic Pelophylax spp. frogs, which were dominated by trematode species of both adult and larval stages. Both larval and terrestrial hosts yielded depauperate trematode communities with accession of aquatic and soil-transmitted nematode species, respectively. Nematode loads peaked in terrestrial Bufo bufo. Helminth infracommunities suggested some differences in host microhabitat or food object selection not detected by their ecology studies. Associations were present in 96% of helminth species (on average, 7.3 associations per species) and dominated positive ones. Species richness and abundances, in most cases, were positively correlated with host size, which could be explained by increasing parasite intake rates over host ontogeny (trematode adult stages) or parasite accumulation (larval Alaria alata). Two larval diplostomid species (Strigea strigis, Tylodelphys excavata) had a negative relationship with host size, which could be caused by parasite-induced host mortality. The adult trematode abundances were higher in larger waterbodies, most likely due to their ecosystem richness, while higher larval abundances in smaller waterbodies could be caused by elevated infection rates under high host densities. [ABSTRACT FROM AUTHOR]

The Tatun Volcanic Group (TVG), located in northern Taiwan, is characterized by acidic hot springs where the outflow of the hot springs may affect the properties of the associated lotic water bodies. We investigated the bacterial diversity and functional profiles of the Peihuang (PHC), HuangGang (HGC), and Nanhuang Creeks (NHC) located in the TVG basin using 16S rRNA gene sequencing coupled with statistical analyses. Water samples were collected from various streams of the creeks for two months of the year. The NHC showed the highest diversity, richness, and a unique number of phyla, which was followed by the HGC. A reduced number of phyla and a lower diversity was noticed in the PHC. The NHC was found to be abundant in the genera Armatimonas, Prosthecobacter, Pirellula, and Bdellovibrio, whereas the HGC was rich in Thiomonas, Acidiphilium, Prevotella, Acidocella, Acidithiobacillus, and Metallibacterium. The PHC was abundant in Thiomonsa, Legionella, Acidocella, and Sulfuriferula. The samples did not show any strong seasonal variations with the bacterial diversity and abundance; however, the relative abundance of each sampling site varied within the sampling months. The iron transport protein- and the sulfur metabolism-related pathways were predicted to be the key functions in all the creeks, whereas the heavy metal-related functions, such as the cobalt/nickel transport protein and the cobalt–zinc–cadmium efflux system were found to be abundant in the HGC and PHC, respectively. The abundance of Bdellovibrio in the NHC, Diplorickettsia in the HGC, and Legionella in the PHC samples indicated a higher anthropogenic impact over the creek water quality. This study provides the data to understand the distinct bacterial community structure, as well as the functional potentials of the three major watersheds, and helps the knowledge of the impact of the physicochemical properties of the TVG hot springs upon the watersheds.

The study of phytoperiphyton communities in waterbodies and watercourses typical for the State Nature Reserve «Kivach» (Republic of Karelia, Russia) included the analysis of their taxonomy composition, ecology and space distribution such as abundance. In total, 156 species were identified from different substrates, belonging to Cyanophyta (Cyanoprokaryota) (21), Ochrophyta (96), Dinophyta (2), Euglenophyta (2), Chlorophyta (35). The paper has discussed the main principles of structure formation of phytoperiphyton communities in rivers. Based on the analysis of taxonomic composition and structure of attached algal communities the similarity features in community composition were revealed. The lists of species dominating in terms of abundance and biomass differ appreciably. Phytoperiphyton communities, dominated by typical attached forms such as Tabellaria flocculosa, Eunotia pectinalis Cocconeis placentula, and Achnanthes minutissima were most common and abundant. However, the bulk of biomass was formed mainly by the filamentous green algae Cladophora glomerata, Mougeotia sp., Zygnema sp., and Bulbochaete sp. We indicated that ecological-geographical composition of algae is dominated by widespread oligohalobic species being acidophilic or indifferent to medium pH. According to the assessments, water in lakes and one brook belonged to the oligosaprobic type and class II of water purity. Periphyton abundance and biomass in waterbodies studied ranging from 0.1 × 104 cell cm-2 to 1301.1 × 104 cell cm-2 and 0.01 mg/cm-2 to 34.70 mg/cm-2.

Changes in land use and land cover (LULC) are the leading contributors to the decline and loss of ecosystem services in the world. The present study covered the Central Rift Valley lakes basin in Ethiopia, focusing on the valley floor and the East and West escarpments, to analyze changes in LULC and to estimate associated losses in ecosystem service values (ESVs). Covering both upstream and downstream areas in the basin, the study addressed major gaps in existing studies by connecting the sources and sinks of material (e.g., sediment and water) in source-to-lake systems. Additionally, the study facilitated the identification of critical areas for conserving natural resources and reversing the decline of associated ESVs in the Central Rift Valley. A post-classification comparison approach was used to detect LULC changes between 1973 and 2020 using four Landsat images from 1973, 1990, 2005 and 2020. The value transfer valuation method was used to estimate the changes in ESVs due to LULC changes. Among the seven major identified LULC classes, farmlands, settlements, and bare lands showed positive changes, while forestlands, grasslands, shrublands and waterbodies showed negative changes over the last 47 years. The expansion of farmlands, for example, has occurred at the expense of grasslands, forestlands and shrublands. The changes in LULC over a period of 47 years resulted in a total loss of US $62,110.4 × 106 in ESVs. The contributors to the overall loss of ESVs in decreasing order are provisioning services (US $33,795.1 × 106), cultural services (US $28,981.5 × 106) and regulating services (US $652.9 × 106). The results imply that addressing the degradation of land and water resources is crucial to reversing the loss of ecosystem services and achieving the national Sustainable Development Goals (SDGs) related to food and water security (SDGs 2 and 6) and life on land (SDG 15).

A pathways risk assessment is a part of an integrated assessment for the horizon scanning of non-indigenous species introductions. We examined past pathways, and their vectors, of aquatic NIS already present in Belarus in order to predict those species likely to spread to Belarus and arrive to Western Europe along the Central European invasion corridor. Twenty-four aquatic non-indigenous macroinvertebrates are known within Belarusian rivers, lakes and reservoirs, six of these have already spread westwards through Belarus. The modes of spread for these NIS were vessel transport, navigation corridors, and natural spread following an initial introduction. [ABSTRACT FROM AUTHOR]

The objective of the present study was to identify the sources and routes of entry of heavy metals and nutrients into several large waterbodies in the arid zone of Kazakhstan, namely Lake Balkhash and Samarkan and Shardara reservoirs. A data visualization method was used for this purpose. Statistical mapping, based on referencing coordinates of the material selection points, was performed with the Statistics 12.0 program. Matching statistical maps with the waterbody contours was performed in Adobe Photoshop. Maps of the spatial distribution of heavy metals (cadmium, nickel, cobalt, lead, zinc and copper) and nutrients were constructed for all three study waterbodies. Data visualization clearly illustrated the relationship between the distribution of pollutants in the study waterbodies, as well as the sources of anthropogenic pollution. Based on the mapping exercise, it was established that Cu and Zn entered the waterbodies mainly in agricultural waste waters, while Cd, Ni, Co, Pb and partly Zn entered the waterbodies mainly in industrial and surface run‐off. Nutrients enter the waterbodies mainly in river and municipal waters. The constructed maps demonstrate the role of the constant flow in the distribution of pollutants in the waters of Lake Balkhash. The results also indicate that statistical mapping is an effective tool for identifying the sources and routes of pollutant entry into waterbodies. The imposition of statistical maps on the contours of waterbodies of concern provides a mapping method allowing for more visually compelling data and information for a wide circle of users and managers. [ABSTRACT FROM AUTHOR]

Arctic lowlands are characterized by large numbers of small waterbodies, which are known to affect surface energy budgets and the global carbon cycle. Statistical analysis of their size distributions has been hindered by the shortage of observations at sufficiently high spatial resolutions. This situation has now changed with the high-resolution (

Water detection algorithms are now being routinely applied to continental and global archives of satellite imagery. However, water resource management decisions typically take place at the waterbody rather than pixel scale. Here, we present a workflow for generating polygons of persistent waterbodies from Landsat observations, enabling improved monitoring and management of water assets across Australia. We use Digital Earth Australia’s (DEA) Water Observations from Space (WOfS) product, which provides a water classified output for every available Landsat scene, to determine the spatial locations and extents of waterbodies across Australia. We generated a polygon set of waterbodies that identified 295,906 waterbodies ranging in size from 3125 m2 to 4820 km2. Each polygon was used to generate a time series of WOfS, providing a history of the change in surface area of each waterbody every ~16 days since 1987. We demonstrate the applications of this new dataset, DEA Waterbodies, to understanding local through to national-scale surface water spatio-temporal dynamics. DEA Waterbodies provides new insights into Australia’s water availability and enables the monitoring of important landscape features such as lakes and dams, improving our ability to use earth observation data to make meaningful decisions.

In 1998, the California Regional Water Quality Control Board (RWQCB) scientists were trained to use the Geospatial Waterbody System (GeoWBS), developed by the Information Center for the Environment (ICE). The Regional Board scientists are currently using the system to report waterbody assessments to the EPA, as mandated by the Clean Water Act. As part of ICE’s continuing work with the GeoWBS database, ICE staff members visited each RWQCB in California to assist the scientists with geographic delineation of waterbodies that will be included in the 303(d) report.

Long-term research (LTR) can provide insights into rotifer ecology that are not possible from short-term studies or experiments. However, such studies have become rarer in recent years due to budgetary constraints. This review examined 5023 published articles about rotifers to determine the number, location and types of LTR studies that had been undertaken. Forty-four articles reported the results of studies that spanned more than 10 years. Of these, most focused on the impacts of climate change, acidification/liming and eutrophication/recovery on waterbodies and soils. However, some investigated ecosystem function, especially in relation to the effects of invasive species or the development of cost effective and comparable sampling techniques. The types of sites examined in these LTR studies included lakes and reservoirs, rivers, lagoons, seas and estuaries and soils, with the lengths of LTR records ranging from 10 to 82 years. Although their geographical locations ranged from North and South America to Asia, the Middle East and Europe, no studies were found from Africa, Australia or Antarctica. This review explores the role of LTR in quantifying the effects of environmental change and highlights gaps in existing knowledge. [ABSTRACT FROM AUTHOR]

Abstract Advancements in drone technology have seen the development of drone-assisted water sampling payloads resulting in the ability of drones to retrieve water samples and physico-chemical data from aquatic ecosystems. The application of drones for water sampling provides the potential to fulfil many aspects of the biological and physico-chemical sampling required to meet large-scale water sampling programmes. This paper reviews the achievements made in the development of drone platforms; advances in specially designed water sampling payloads; advances in incorporating off-the-shelf probes and the ability of drone-assisted water sampling payloads to capture water and physico-chemical data from freshwater environments. However, drone-assisted water sampling is still in its infancy and several key limitations include the small volume of water captured via drones to date, the low rate of successful sample capture and the legislative restrictions limiting the distance drones can be flown from the operator. Of critical importance, however, are the clear inconsistencies observed between water chemical parameters obtained using drone-assisted and traditional water sampling methods. Consequently, water samples and physico-chemical data obtained using drones may not provide the level of reliability and accuracy needed to meet the needs of large-scale water sampling programmes. Solutions aimed at addressing these limitations and developing the potential of drones to conduct water samples include: modifying larger drones with greater payload capacity, facilitating the capture of greater volumes of water; technological developments to increase success rates of water capture; planning fieldwork for operation beyond visual line of sight (BVLOS); employing real-time physico-chemical probes; and integrating robust statistical experimental designs. In addition, detailed cost benefit analyses are required to investigate if drones would result in a meaningful financial saving to water sampling programmes. However, it is envisaged that drone-assisted water sampling will act as a pivotal supporting tool if such current limitations can be addressed by future research. Graphical abstract Unlabelled Image Highlights • Previous research has demonstrated the potential of drone-assisted water sampling. • Advancement in off-the-shelf probes allows for real-time data collection. • Reported sample volumes of 330 ml may be insufficient for water sampling programmes. • Research needs to compare the precision and accuracy of data collected via drones. • Cost-benefit analyses are required before water sampling programmes utilise drones. [ABSTRACT FROM AUTHOR]

This study aimed to assess the spatial and seasonal distribution and anthropogenic sources of trace elements (Li, Be, Al, V, Cr, Co, Ni, Cu, Zn, Se, Mo, Ag, Cd, Sb, Ba, Tl, Pb, and U) by ICP-MS in the Ave River lower basin, Portugal. Mean values (µg L−1) of Al (2384), Zn (55.3), Se (34.6), Cu (24.7), Pb (12.7), Ag (0.75), and Cd (0.66), exceeded the water quality guidelines for the protection of aquatic life. The decreasing order of trace elements concentrations in surface water and sediments was, respectively: Al > Zn > Se > Mo > Li > Ba > V > Cu > Pb > Ni > Cr > U > Be > Co ≈ Sb > Ag ≈ Cd > Tl; and Al > Zn > Li > Ba > Cu > Pb > Cr > V > Ni > Co > U > Be > Se ≈ Mo ≈ Tl ≈ Cd ≈ Sb ≈ Ag. Moreover, the concentrations of nitrate values were higher than 50 mg L−1. To distinguish natural from anthropogenic sources, the geo-accumulation index (Igeo) and the enrichment factor (EF) of sediments were determined. Igeo revealed high contamination by Al, Mn, Ba and Zn, while EF evidenced enrichment for Se, Cd, Zn, Li, Cu, Ag, Pb and U. Bioaccumulation factors (BF) in flora suggested that macroalgae, Medicago marina L. and Plantago lanceolata L., might be accumulators of Se, Mo, Ba and Pb (BF > 1). The highest translocation factor (TF) was found for Mo in leaves (33.6) and flowers (28.1) of P. lanceolata L.. Article Highlights: The present work regards a comprehensive study on the occurrence, spatial distribution, possible sources and bioaccumulation of trace elements in this ecosystem, namely in water, sediments and native local flora (plants and macroalgae). In fact, various studies have demonstrated the high anthropogenic pressure of Ave River estuary, the presence of several classes of pollutants and the negative impacts in local aquatic organisms. Nevertheless, there are no studies regarding the monitoring of a large panel of trace elements considering three different matrices (water, sediments and plants) and their possible correlation Pollution indices such as geo-accumulation (Igeo) and enrichment factor (EF) were also determined to investigate sources of these elements. Igeo revealed high contamination by Al, Mn, Ba and Zn, while EF evidenced enrichment for Se, Cd, Zn, Li, Cu, Ag, Pb and U. Bioaccumulation factors (BF) in flora suggested that macroalgae, Medicago marina L. and Plantago lanceolata L. might be accumulators of Se, Mo, Ba and Pb These monitoring data are important to alert local and national authorities to take actions and decisions to protect and improve water quality of Portuguese waterbodies and meet national and European requirements [ABSTRACT FROM AUTHOR]

Data on the species diversity of the genus Micrasterias C. Agardh ex Ralfs representatives from water bodies of West Siberia and their occurrence in zones and subzones are generalized. Twenty-three specific and intraspecific taxa from the order Desmidiales are now known. The representatives of the family occur in mosaic order in the entire area of West Siberia. The highest number of taxa (15) was revealed in the middle taiga; significantly fewer were determined in southern and northern taiga, 9 and 8 taxa, respectively; and 3'5 taxa were in other zones. No such species were discovered in the steppe zone. Thirteen species (18 taxa) of the genus were found in lakes of different types, 5 species (7 taxa) in watercourses, 4 (5 taxa) were found in swamps, and 4 species were detected in temporal water bodies. The analysis performed on the adaptation of the species to environmental conditions demonstrated that representatives of this genus might serve as indicators of acid and brackish water. In relation to mineralization, halophobes are predominant (11 taxa) and acidophilus plants (15 taxa) predominate as pH indicators. [ABSTRACT FROM AUTHOR]

Apple snails are renowned for their strong impacts on aquatic vegetation and ecosystem function in invaded regions but the existing knowledge on their role in aquatic ecosystems and communities in their native range is scarce. The variation in palatability of five submersed macrophytes, the preference of Pomacea canaliculata for them and the potential effects of its differential grazing on macrophyte assemblages in Southern Pampas were investigated. In no-choice trials, macrophytes showed differences in palatability that were correlated to physical defences and not to nutritional values. In free-choice trials, preference was consistent with the palatability ranking. In a mesocosms experiment, Chara contraria and Zannichellia palustris were totally eradicated by apple snails, the coverage of Stuckenia striata increased only when they were absent and Ludwigia peploides and Myriophyllum quitense were not affected. The live biomass of Z. palustris, S. striata and M. quitense was reduced by apple snails. Total live and dead biomasses were lower, and chlorophyll-a concentrations higher, in the mesocosms with apple snails. Our results indicate that P. canaliculata has a keystone role in its native range and that its differential grazing could shape the structure and composition of submersed vegetation and promote shifts to turbid-water states or maintain them. [ABSTRACT FROM AUTHOR]

The use of biodiversity surrogates is often suggested to increase the cost-effectiveness of biomonitoring programs, as this demands less time and taxonomic expertise. In addition, the detection of multi-taxon associations is a first step toward a better understanding of how organisms interact with each other. Such a multi-taxon association is termed a congruence, and can be detected through measuring the similarity in the distributional patterns shown by different biological groups. To assess the ability of different taxa to serve as surrogates for others, we carried out a Procrustes analysis on the beta diversity patterns of seven biological groups (aquatic birds, Amphibians, Macrophytes, Coleoptera, Odonata, Heteroptera and phytoplankton) in 35 ponds of the Cerrado biome. We found that: (i) the values of congruence in the studied ponds were weak; (ii) among all the biological groups compared, the highest congruence was found between amphibians and macrophytes; (iii) amphibians were congruent with the Coleoptera, Heteroptera, and macrophytes; (iv) the different taxa studied had different responses to environmental conditions; and (v) although they showed relatively weak congruence with the other taxa in each pond environment, amphibian communities were the most strongly influenced by environment variables. Almost all the communities observed in these systems showed unique pattern and thus should be studied and monitored in their entirety. We intended to choose an indicator group to better represent the biodiversity in man-made tropical ponds. For these propose we tested the congruence pattern among several aquatic communities. Two explanations have been previously proposed for the congruence among different taxa: (i) that different taxa have the same responses to environmental gradients (Padial et al., 2012a); or (ii) that congruence occurs because of ecological interactions among different groups, for instance, the relationships between predators and prey (Larsen et al., 2012). We hypothesized that the communities that depend directly on both water and land are likely more congruent with each other (e.g., amphibians, Odonata (in part), and macrophytes) than those that live in only one of these habitats (e.g., phytoplankton, aquatic insects, and birds). Although the congruency found for them was weak, amphibians were able to partially represent patterns in the abundance of Coleoptera, Heteroptera, and macrophytes. In terms of richness, macrophytes were able to partially represent patterns in Odonata, Coleoptera and birds. In this way, at least for abundance, our results partially supported the hypothesis that the biotic communities that depend directly on both water and land (e.g., amphibians and macrophytes) are more congruent with each other than those living only in one of these environments.Ultimately, we do not recommend the use of a single surrogate taxon to measure biodiversity: weak overall congruence between taxa; limited biological knowledge about tropical artificial ponds; and numerous taxa whose diversity patterns could not be represented by any surrogate group (phytoplankton, Heteroptera, and birds) illustrate the unsuitability of this approach. [ABSTRACT FROM AUTHOR]