Goggles and Water Competence: An Addendum

Effect of water quality on species richness and activity of desert-dwelling bats

The study of tadpole assemblages allows inferring habitat availability and using their occupation as a means of proxy for the effective reproduction of the species, contributing to complementary information for the study of their adult forms. Environmental variables, represented by abiotic variables, vegetation structure, matrix management, and landscape elements, affect species having reproductive modes associated with oviposition and development in bodies of water. In the Orinoco region, most amphibians have complex life cycles and deposit their eggs in highly dynamic lentic bodies of water. Therefore, it is important to know how larval assemblages change over short periods of water accumulation and their relationship with environmental variables. Fieldwork was conducted during 9 weeks of larval sampling, from the beginning of the rainy season. We evaluate changes in anuran assemblages associated with water accumulation in five temporary water bodies of anthropogenic (road or pasture) and natural (savanna or gallery forest) origin. Twenty environmental variables were evaluated and measured in the center of each water body. Of these, nine landscape variables were measured only once during the study. The other eleven variables, representing management practices, physicochemical and structural characteristics of the water bodies, were measured weekly during the 3 months of sampling. We explored differences in the structure and diversity of larval-stage anuran assemblages using statistical tests suitable for small sample sizes (i.e., permutational multivariate analysis of variance PERMANOVA and the distance-based linear modeling DistLM). Of the 14 species found, two species had remarkedly high abundances from whichRhinella humboldti(19% of the total tadpole abundance) was a generalist inhabiting the natural and anthropogenic water bodies, whileLeptodactylus insularum(18% of the total tadpole abundance) was a specialist at a natural pond in the savanna. The natural water bodies contained the highest number of species (between 10 and 12) and a total abundance of larvae (between 847 and 485 individuals). In contrast, the anthropogenic water body tracks generated by tractors were only occupied by two species with 50 individuals in total, while the water body generated by the trampling of cattle in pastures had three species with 474 individuals. These three species that inhabited the anthropogenic puddles were also found in the natural ponds and none of the eight species of hylids inhabited the puddles. In each field trip, all the tadpoles were collected from the sampled bodies of water. However, a week later, we found that each of the water bodies had been recolonized by four species (Leptodactylus fuscus, Leptodactylus fragilis, Elachistocleis ovalis,andR. humbolti). The variables with the highest explanatory power on the variation of anuran assemblage structure throughout all the water bodies were height of plants, number of cattle, distance to the nearest native forest edge, distance to an anthropic lentic body of water, distance to a natural lentic body of water, and pH. The bodies of water immersed in the natural cover were more diverse and had a greater degree of spatial and temporal species turnover. Our study calls for the importance of understanding the turnover of larval stage anurans over short periods, associated with water accumulation, in highly dynamic systems such as natural ponds and anthropogenic puddles. The importance of species traits and local processes is also highlighted, from environmental variables to human management activities, in the conservation of amphibian assemblages.

The epidemiological implications of fresh water snails have continued to pose serious challenge to schistosomiasis control. A survey was conducted to ascertain the species diversity and abundance of aquatic snails in man-made and natural water bodies in Benue state, Nigeria. Eight sites were sampled for the presence of snails using the sweep net and handpicking method. Snails captured were carefully placed into pre- labelled specimen bottles and transported to Benue State University Zoology Laboratory for identification. Plants commonly known to be suitable for snail attachment were collected and brought to the Botany laboratory for identification. The physiochemical parameters of the water were also documented. Data was processed using Analysis of Variance (ANOVA). A total of 1038 snails belonging to 3 species were identified; Melanoides tuberculata, 468 (45.1%), Lanistes libycus 210 (20.2%), Bulinus species 360 (34.7%). Northbank dam harboured 2 (Bulinus and Melanoides) out of the 3 species recorded, making it the most favourable habitat sampled. Bulinus species was the most abundant in the natural habitats while it was replaced by Melanoides tuberculata in the man-made water bodies. ANOVA revealed a significant difference in relation to snail species encountered, and species abundance in habitats sampled (P< 0.05). The predominant aquatic flora encountered were Ipoemoea aquatic and Nelsonia species. The study revealed that natural and man-made water bodies in Makurdi and Ochobo support the breeding of snail species that have serious epidemiological implications.

Previous investigations on Sicilian man made lakes suggested that physical factors, along with the specific morphology and hydrology of the water body, are important in selecting phytoplankton species. In particular, the variations of the zmix/zeu ratio due to the operational procedure to which reservoirs are generally subject were recognised as a trigger allowing the assemblage shift. To investigate if these variations may be considered analogous to those occurring in natural lakes as trophic state and phytoplankton biomass increase, causing a transparency decrease and a contraction of the euphotic depth, phytoplankton were collected in two natural water bodies, one mesotrophic (Lake Biviere di Cesaro) the other eutrophic (Lake Soprano), and compared with those collected in two reservoirs with analogous trophic characteristics (Lake Rosamarina, mesotrophic and Lake Arancio, eutrophic). Particular attention was paid to the dynamics of two key groups: Cyanophytes and chlorophytes. In all four water bodies, transparency mainly depended on chlorophyll level. Annual average value of phytoplankton biomass in the mesotrophic environments was below 2.0 mg l−1, whereas in the eutrophic systems it was well above 10 mg l−1. All water bodies showed the presence of cyanophytes (e.g. Anabaena spp., Anabaenopsis spp., Microcystis spp., Planktothrix spp.) and chlorophytes (e.g. Chlamydomonas spp., Botryococcus spp., Oocystis spp., Scenedesmus spp., Pediastrum spp.), but their relative proportions and body size dimensions were different. In particular, small colonial chlorophytes and large-colony forming cyanophytes were most common in the most eutrophic water bodies, whereas larger colonies of green algae in those with a lower trophic state. The results showed that, under the same climatic conditions, autogenic (increase of biomass, decrease in light penetration and euphotic depth) and allogenic (use of the stored waters, anticipated breaking of the thermocline, increase of the mixing depth) processes may shift the structure of phytoplankton assemblage in the same direction even though the quantity of biomass remains linked to nutrient availability.

Anthropogenic water bodies as drought refuge for aquatic macroinvertebrates and macrophytes

Artificial and natural water bodies, such as reservoirs, ponds, rivers and lakes, are important components of water-related ecosystems; they are also important indicators of the impact of human activities and climate change on surface water resources. However, due to the global and regional lack of artificial and natural water bodies data sets, understanding of the changes in water-related ecosystems under the dual impact of human activities and climate change is limited and scientific and effective protection and restoration actions are restricted. In this paper, artificial and natural water bodies data sets for China are developed for the years 2000, 2005, 2010, 2015 and 2020 based on satellite remote sensing surface water and artificial water body location sample data sets. The characteristics and causes of the temporal and spatial distributions of the artificial and natural water bodies are also analyzed. The results revealed that the area of artificial and natural water bodies in China shows an overall increasing trend, with obvious differences in spatial distribution during the last 20 years, and that the fluctuation range of artificial water bodies is smaller than that of natural water bodies. This research is critical for understanding the composition and long-term changes in China’s surface water system and for supporting and formulating scientific and rational strategies for water-related ecosystem protection and restoration.

Given the significance of fish farming as a promising sector of Ukraine’s agriculture, and the Mykolaiv, Odesa, and Kherson regions are characterised by a significant number of natural and artificial water bodies, the study of aquatic bioresource catching indicators in the south is both important and timely. The research aimed to determine trends in aquatic bioresource catching in southern Ukraine during the period 2018-2023 and to analyse the factors influencing the extraction of aquatic bioresources. This article presents overall catch statistics, as well as catch data for inland waters of the south and aquaculture conditions over the past six years. It has been established that the catch of aquatic biological resources in southern Ukraine has been declining each year from 2018 to 2023. The negative trends in aquatic bioresource catching, both in aquaculture and natural water bodies, are linked to several factors. In particular, the decline in catches has been influenced by: COVID-19; the unstable military and political situation in Ukraine, associated with Russian military aggression; outdated material and technical base of fishing enterprises; lack of government subsidies and foreign investment in the sector; imperfections in the systems of control and regulation of the extraction of aquatic bioresources; and irrational use of the bioproductive potential of water bodies in southern Ukraine. Based on a scientific analysis of the dynamics of aquatic bioresource extraction in southern Ukraine and the identification of key factors contributing to the decline in catches, a set of measures has been developed to positively impact the fishing industry. These measures include: attracting foreign investment in fish farming; improving the quality of monitoring, regulation, and control over aquatic bioresource catching at local, regional, and state levels; restoring critical fish farming infrastructure damaged by Russian aggression; ensuring sustainable fisheries management; and introducing EU best practices into Ukrainian fish farming. The scientific results obtained from this research can be used in practice to ensure the sustainable development of fisheries in southern Ukraine

To demonstrate the presence of culturable and nonculturable viable pathogenic Vibrio cholerae O1 in fresh water environments of a cholera-endemic region in India. Conventional culture and ciprofloxacin DFA-DVC were utilized to investigate the existence of V. cholerae O1. We isolated pathogenic culturable V. cholerae O1 from water samples collected from cholera-affected areas. No culturable V. cholerae O1 was isolated from water and plankton samples from natural fresh water bodies. Ciprofloxacin was used for DFA-DVC as V. cholerae O1 are 100% resistant to nalidixic acid in our region. The viable but nonculturable O1 cells were demonstrated in 2.21 and 40.69% samples from natural water bodies and cholera-affected areas, respectively. Vibrio cholerae O1 VBNC could be demonstrated using modified DFA-DVC technique. Ciprofloxacin is preferable to nalidixic acid for DVC in view of existing high-level resistance to nalidixic acid in cholera-endemic areas. We endorse that for public health surveillance, cholera outbreak investigation and disease control water samples in addition to culture should be tested for V. cholerae using DFA-DVC.

Ponds—small, isolated freshwater bodies—have vanished in large numbers during the last decades. Despite such great loss, the number of natural small water bodies has still remained quite high in Estonia. Nevertheless, many pond-related species, including amphibians such as the northern crested newt Triturus cristatus and the common spadefoot toad Pelobates fuscus—are in decline in Estonia, suggesting that the conditions of extant natural ponds might not be optimal. However, these conditions have never been examined. To halt the decline of these two pond-breeding species, more than 400 ponds have been constructed or restored from 2004 to 2014 in Estonia. In this study we compared 85 natural and 85 constructed ponds (which were created or restored especially for T. cristatus and/or P. fuscus) to find out: (i) what the main differences are between natural ponds and ponds specially created for threatened species; (ii) whether natural ponds provide breeding conditions for local amphibians; (iii) given the decline of T. cristatus and P. fuscus, what are the characteristics lacking in natural ponds, due to which they are not providing quality breeding habitats for these species. Whereas the constructed ponds were located in open habitats with mineral soils, the natural ponds were mainly in mires and forests, being thus more shaded. Amphibian diversity was higher in the constructed ponds and was positively related to the depth of the pond, the clarity of the water, the presence of slanting slopes, the absence of fish and the presence of nearby fields. T. cristatus preferred constructed ponds for reproduction, while the breeding site selection of P. fuscus was determined mainly by terrestrial habitat characteristics. Importantly, when the threatened species were removed from the sample, the diversity of common amphibians did not differ between natural and constructed ponds, suggesting that in our study sites natural water bodies act still as breeding sites for common species, but not for threatened ones. We conclude that pond construction is an important tool to halt the decline of threatened species, even in landscapes where natural ponds are still preserved.

Staphylococcus aureus is a potentially harmful human pathogen associated with both nosocomial and community-acquired infections with increasingly antibiotic resistance. Although microbial contamination of marine waters is predicted to be responsible for millions of gastrointestinal, and acute respiratory infections, and several skin infections, there is little information regarding the microbial contamination of water bodies in many Sub-Saharan countries. Therefore, this study aimed at determining the antimicrobial susceptibility of S. aureus isolated from recreational waters and natural water bodies in Lusaka, Zambia. This was a cross-sectional study with a total of 90 water samples collected from recreational and natural water bodies. To isolate S. aureus, standard microbiological methods were used while the Kirby-Bauer disk diffusion method was used for susceptibility testing. Methicillin-resistant Staphylococcus aureus was detected by use of cefoxitin. The overall results showed that there was 36.7% bacterial contamination in the waters tested. From the 90 samples collected, a total of 33 bacteria were isolated, of which 12 (36.4%) were Coagulase Negative Staphylococcus, 9 (27.2%) were S. aureus and 12 (36.4%) were non-staphylococcus species. All the isolates showed 100% resistance to penicillin G and ampicillin. The S. aureus isolates were most susceptible to chloramphenicol (88.9%), cefoxitin (88.9%), ciprofloxacin (100%), amikacin (88.9%) and gentamicin (88.9%). Only 11.1% of isolates showed phenotypic resistance to methicillin after testing against cefoxitin. The results from this study signify that recreational and natural water bodies in Lusaka, Zambia may be possible reservoirs of antibiotic-resistant S. aureus which may possibly be transmitted to humans when using the same waters.

Dam reservoirs play an important role in meeting sustainable development goals and global climate targets. However, particularly for small dam reservoirs, there is a lack of consistent data on their geographical location. To address this data gap, a promising approach is to perform automated dam reservoir extraction based on globally available remote sensing imagery. It can be considered as a fine-grained task of water body extraction, which involves extracting water areas in images and then separating dam reservoirs from natural water bodies. A straightforward solution is to extend the commonly used binary-class segmentation in water body extraction to multi-class. This, however, does not work well as there exists not much pixel-level difference of water areas between dam reservoirs and natural water bodies. We propose a novel deep neural network (DNN) based pipeline that decomposes dam reservoir extraction into water body segmentation and dam reservoir recognition. Water bodies are firstly separated from background lands in a segmentation model and each individual water body is then predicted as either dam reservoir or natural water body in a classification model. For the former step, point-level metric learning with triplets across images is injected into the segmentation model to address contour ambiguities between water areas and land regions. For the latter step, prior-guided metric learning with triplets from clusters is injected into the classification model to optimize the image embedding space in a fine-grained level based on reservoir clusters. To facilitate future research, we establish a benchmark dataset with earth imagery data and human labelled reservoirs from river basins in West Africa and India. Extensive experiments were conducted on this benchmark in the water body segmentation task, dam reservoir recognition task, and the joint dam reservoir extraction task. Superior performance has been observed in the respective tasks when comparing our method with state of the art approaches. The codes and datasets are available at https://github.com/c8241998/Dam-Reservoir-Extraction.

<p indent="0mm">Organic micropollutants (OMPs) are ubiquitous in natural water bodies and can have negative impacts to health of aquatic ecosystems and human beings. It is of importance to investigate fate of the OMPs so as to assess their environmental risks. Photodegradation is an important pathway to transform the OMPs in natural water bodies, including direct photolysis and indirect photodegradation induced by photosensitizers. Dissolved organic matter (DOM) is an important photosensitizer that is ubiquitous in water bodies. DOM plays an important role in photodegradation of the OMPs especially for those recalcitrant to direct photolysis. On one hand, DOM can produce photochemically produced reactive intermediates (PPRIs), e.g., hydroxyl radical (HO^•), singlet state oxygen (¹O₂), and excited triplet-state DOM (³DOM*), after absorbing solar irradiation. The PPRIs are capable of inducing indirect photodegradation of the various OMPs. On the other hand, DOM can exhibit inhibition effects (light screening effects and quenching effects) on photodegradation of the OMPs. Chromophores in DOM can compete photons with the OMPs and thus inhibit direct photolysis of some OMPs, exhibiting the light screening effects. Antioxidants like phenolic moieties in DOM can quench the formed PPRIs and reduce the reactive intermediates of OMPs to the parent OMPs, manifesting the quenching effects. Generally, the effects of DOM on photodegradation of the OMPs depend on sources of DOM. DOM can derive from autochthonous (microbial) and allochthonous (terrestrial) sources based on its forming processes. Many previous studies on DOM mainly focused on formation pathways of PPRIs, reactivity of ³DOM* from different sources, and effects of different DOM on photodegradation of the OMPs. These efforts in early phase laid a foundation for emerge of the discipline of environmental (aquatic) photochemistry. In recent decades, many studies focused on photochemical properties of autochthonous and allochthonous DOM extracted from freshwater bodies. Very limited studies focused on seawater DOM (S-DOM). S-DOM may undergo longer period of photobleaching than freshwater DOM. Due to sources of riverine inputs, atmospheric depositions, wastewater discharges and mariculture activities, S-DOM in coastal seawaters can be quite different from S-DOM in distant seas or DOM in inland freshwater bodies. Therefore, S-DOM may potentially exhibit photochemical properties different from that of freshwater DOM. As seawater is a final sink of many OMPs, it is necessary to investigate photochemical property of S-DOM and its effects on photodegradation of the OMPs. Some recent studies did prove that S-DOM and freshwater DOM has different photochemical reactivities towards some OMPs. Data on environmental photodegradation kinetics are necessary for assessing fates, persistence and ecological risks of the OMPs. However, translation and extrapolation of reaction rates from environment to environment and laboratory to environment is a challenging task. Underwater downward sunlight attenuation in field water bodies should be taken into consideration when estimating photolytic persistence of the OMPs. More research efforts are needed to develop prediction models on photodegradation kinetics of OMPs in different field water bodies, and to develop prediction models (such as quantitative structure-activity relationship models that can predict second-order reaction rate constants between OMPs and PPRIs) on photodegradation kinetics parameters of the vast and ever-increasing number of OMPs (or environmental organic chemicals). In this review, the recent progresses in aquatic photochemistry of DOM were summarized into three aspects, mechanisms for photogeneration of PPRIs from DOM of different sources, effects of DOM from different sources on photodegradation of OMPs, and photodegradation kinetics prediction models of OMPs in natural water bodies. In addition, potential differences in the effects of freshwater DOM and S-DOM on photodegradation of OMPs were discussed. Based on the research progresses, future efforts in the field of aquatic environmental photochemistry were suggested.

Recently reported detection of SARS-CoV-2 in wastewater around the world has led to emerging concerns on potential risk in water bodies receiving treated wastewater effluent. This review aims to provide an up-to-date state of key knowledge on the impact of SARS-CoV-2 in natural water bodies receiving treated wastewater. In this review, SARS-CoV-2 concentrations in wastewater, expected removal in WWTPs, and possible dilution and decay in water bodies are reviewed based on past studies on SARS-CoV-2 and related enveloped viruses. We suggest a quantitative microbial risk assessment (QMRA) framework to estimate the potential risk of SARS-CoV-2 in natural water bodies through various water activities. Dose–response model of SARS-CoV and Poisson’s distribution is employed to estimate possible viral ingestion and the annual chance of infection through several water activities in natural water bodies. Finally, future perspectives and research needs have been addressed to overcome the limitations and uncertainty in the risk assessment of SARS-CoV-2 in natural water bodies.

BackgroundIn the past decade fish farming has become an important economic activity in the Occidental Brazilian Amazon, where the number of new fish farms is rapidly increasing. One of the primary concerns with this phenomenon is the contribution of fishponds to the maintenance and increase of the anopheline mosquito population, and the subsequent increase in human malaria burden. This study reports the results of a 2-year anopheline abundance survey in fishponds and natural water bodies in a malaria-endemic area in northwest Brazil. The objective of this study was to investigate the contribution of natural water bodies (rivers, streams, creeks, ponds, and puddles) and artificial fishponds as breeding sites for Anopheles spp. in Mâncio Lima, Acre and to investigate the effect of limnological and environmental variables on Anopheles spp. larval abundance.MethodsNatural water bodies and fishponds were sampled at eight different times over 2 years (early, mid and late rainy season, dry season) in the Amazonian town of Mâncio Lima, Acre. Anopheline larvae were collected with an entomological dipper, and physical, chemical and ecological characteristics of each water body were measured. Management practices of fishpond owners were ascertained with a systematic questionnaire.ResultsFishponds were four times more infested with anopheline larvae than natural water bodies. Electrical conductivity and the distance to the nearest house were both significant inverse predictors of larval abundance in natural water bodies. The density of larvae in fishponds raised with increasing border vegetation. Fishponds owned by different farmers varied in the extent of anopheline larval infestation but ponds owned by the same individual had similar infestation patterns over time. Commercial fishponds were 1.7-times more infested with anopheline larvae compared to fishponds for family use.ConclusionsThese results suggest that fishponds are important breeding sites for anopheline larvae, and that adequate management activities, such as removal of border vegetation could reduce the abundance of mosquito larvae, most importantly Anopheles darlingi.

Phytoplankton have a crucial role in the conversion of greenhouse gas sources and sinks in natural water bodies, such as lakes, rivers, and oceans. In response to environmental changes, phytoplankton adapt by altering their carbon utilization strategies, which affect carbon fixation rates and carbon fluxes at the water–air interface. This paper classifies and summarizes the main carbon utilization strategies of phytoplankton in terms of carbon acquisition, carbon metabolism, and carbon emission. Their carbon acquisition strategy determines their carbon uptake rate, while their carbon metabolism strategy affects their carbon fixation potential. Moreover, their carbon emission strategy determines the final net carbon fixation. A systematic study of phytoplankton carbon utilization strategies is important for the development of phytoplankton-based wastewater treatment technologies, understanding of algal greenhouse gas fixation, and assessment of greenhouse gas sources and sinks in natural water bodies. This article provides a comprehensive understanding of the ecological role of phytoplankton in natural water bodies and offers valuable references for related research. Furthermore, our research sheds light on the carbon metabolism and emission processes of phytoplankton. By analyzing the carbon metabolism and emission of phytoplankton under different carbon utilization strategies, we can more accurately evaluate the impact of phytoplankton on the carbon cycle in natural water bodies, which can contribute to environmental protection and sustainable development.