Natural Water Sources Research Articles

Multivariate Statistical Methods Used in Determining the Hydrogeochemical Surfaces of Groundwater in Yusufiya District

For the importance of groundwater and being the second natural source of water after surface water, it is necessary to know the quality, features and hydrological surfaces of this water. For this reason, 15 wells were chosen in the Al Yusufiyah sub-district to study the quality of groundwater based on multivariate statistical methods as well as the Piper chart. These methods proved successful in characterizing the study of groundwater chemistry and can be relied upon for ground and surface water in other regions. The quality of the groundwater in Al Yousifiyah, according to Piper’s scheme, the alkalinity increases with the presence of sulfate and chloride, depending on the type of soil. From the analysis of the correlation matrix, the totals were found to be Ca, Mg, and Cl., Ca, Mg, Cl, and SO4, as well as Ca, Na, Mg, Cl, SO4, and HCO3. From the mass analysis, the first K, second Na, third Ca, fourth Mg, SO4 and fifth Cl, HCO3 were obtained. Finally, from the main component analysis, hydrogeochemical facies were found: Cl, SO4, Ca, HCO3, Mg, and Na, Respectively.

Wastewater Treatment and Reuse for Sustainable Water Resources Management: A Systematic Literature Review

Wastewater treatment involves the extraction of pollutants, removal of coarse particles, and elimination of toxicants. Moreover, wastewater treatment kills pathogens and produces bio-methane and fresh manure for agricultural production. The connection between waste management and sustainability created the basis for this research. Wastewater treatment is part of the efforts to minimize water waste, minimize pressure on natural sources of water, and create a pathway for clean energy. A systematic literature review was selected for this study to evaluate and synthesize the available evidence in support of wastewater treatment for both economic and environmental sustainability. The articles were evaluated using the PRISMA framework to identify the most appropriate articles for inclusion. A total of 46 articles were selected based on their content validity, relevance to the research question, strength of evidence, year of publication (2000–2023), and relevance to sustainable resource management. The findings indicate that wastewater treatment enables sustainable resource management by improving the supply of clean water, and minimizing pressure on natural resources, energy recovery, and agricultural support. Wastewater treatment provides one of the most sustainable approaches to water conservation, energy production, and agricultural productivity.

In situ sea urchin carbonates analysis by LA-MC-ICP-MS to identify lead isotopic signatures: A case study at Trindade Island (South Atlantic Ocean versus anthropogenic)

Isotope ratios of lead (Pb) are increasingly applied to trace pollution sources in marine settings, using mostly carbonate remains of living organisms. However, this data has never been acquired in sea urchin carbonates. Sea urchins are widely distributed in marine settings and have been recognized for their ability to bioaccumulate heavy metals and their skill to track environmental changes. Thus, this work intends to perform, for the first time in-situ analysis of Pb isotope ratios using LA-ICP-MC-MS in sea urchin spines collected on the beaches from Trindade Island (SE Brazil). Trindade Island is a protected environmental area, almost uninhabited, located in a remote region of the South Atlantic Ocean (1200 km from the mainland). The results obtained in sea urchins spines collected on the beaches from Trindade Island varied from: 1.03 to 1.30 (mean 1.18 ± 0.06) for 206Pb/207Pb; 1.44 to 2.23 (mean 2.10 ± 0.07) for 208Pb/206Pb and 2.22 to 2.87 (mean 2.48 ± 0.15) for 208Pb/207Pb. The biplot of 208Pb/206Pb versus 206Pb/207Pb ratios show greater dispersion of isotopic values in the sea urchin spines than in the geogenic data of the Vitória-Trindade Ridge (VTR; used as reference) and the surface water from the Tropical Atlantic Ocean. While the Pb isotope ratios of rocks and sediments of the VTR are quite similar and present intermediate values, a significant variation of the isotopic signature in the sea urchin spines was observed. The comparison of the sea urchin spines 206Pb/207Pb ratios with data published in the literature from several materials suggests the presence of anthropogenic contamination on Trindade Island caused using fossil fuels. The range of variation of Pb isotopes analyzed in sea urchin spines suggests mixing between the natural source (the rocks and sediments of the Vitória-Trindade Ridge) and surface water masses of the Tropical South Atlantic and anthropogenic sources.

Automated Drone-Delivery Solar-Driven Onsite Wastewater Smart Monitoring and Treatment System.

Treating potential polluted water sources is urgent and challenging, especially for natural water sources. Numerous research groups focus on either smart water monitoring or new adsorbent. However, either aspect alone is insufficient for complex nature water source treatment. Here, integrating the state-of-art machine learning technique, a sustainable silk-based bioadsorbent, and wireless Internet of Things, an integrated automated drone-delivery solar driven onsite water monitoring & treatment system (WMTS) for the contaminated nature water sources is developed. In short, the embedded sensors and microprogrammed control unit capture and upload the real-time monitoring data to the cloud server for data analysis and optimized treatment strategy. Meanwhile, a grid map system based on the satellite remote sensing images directs the minimum number of WMTS units to cover the entire polluted region. Finally, unmanned aerial vehicles provide autonomous dispatch, operation, and maintenance, especially in hard-to-reach sites. Overall, this work offers a general, sustainable, energy-efficient, and closed-loop solution toward efficiently alerting and on-site treating nature water source contamination.

Climate change, water availability, and the burden of rural women’s triple role in Muyuka, Cameroon

Many rural communities in Cameroon rely on natural sources of water (rivers, springs, and rainfall) for agriculture and domestic use. Access to and reliability of water from these sources depend on changes in rainfall and temperatures. Household roles in Cameroon are traditionally defined along gender lines, with women playing key roles in food production, home management, and caregiving. Water is indispensable for women to successfully accomplish these roles. Climate variability is affecting reliability of water in Cameroon; however, impacts are not the same for men and women in rural communities. This paper examines how climate-induced water challenges adversely affect women’s ability to perform their multiple roles in a predominantly farming community in southwest Cameroon. Data collected by survey from a hundred women, supplemented by interviews with local water and agricultural technicians, suggest that climate change has contributed to the disappearance of several water sources and decreased volume of others. This hampers local water availability, compromises women’s productivity, and increases the burden on women’s triple roles as farmers, caregivers, and home managers. Although individual women are implementing some adaptation strategies, comprehensive public policy measures, including promotion of better land use management and gender-sensitive technologies, are vital to sustain efforts against climate change in Cameroon.

Enhancing Cu2+ Ion Removal: An Innovative Approach Utilizing Modified Frankincense Gum Combined with Multiwalled Carbon Tubes and Iron Oxide Nanoparticles as Adsorbent.

Aquatic pollution, which includes organic debris and heavy metals, is a severe issue for living things. Copper pollution is hazardous to people, and there is a need to develop effective methods for eliminating it from the environment. To address this issue, a novel adsorbent composed of frankincense-modified multi-walled carbon nanotubes (Fr-MMWCNTs) and Fe3O4 [Fr-MWCNT-Fe3O4] was created and subjected to characterization. Batch adsorption tests showed that Fr-MWCNT-Fe3O4 had a maximum adsorption capacity of 250 mg/g at 308 K and could efficiently remove Cu2+ ions over a pH range of 6 to 8. The adsorption process followed the pseudo-second-order and Langmuir models, and its thermodynamics were identified as endothermic. Functional groups on the surface of modified MWCNTs improved their adsorption capacity, and a rise in temperature increased the adsorption efficiency. These results highlight the Fr-MWCNT-Fe3O4 composites' potential as an efficient adsorbent for removing Cu2+ ions from untreated natural water sources.

Monitoring the dynamics of acid mine drainage affected stream surface water hydrochemistry at Jaintia Hills, Meghalaya, India.

Streams are pristine natural life-thriving water sources for people living in the mountainous proximity of NE India, where water scarcity is a common occurrence in most villages and towns. In the last few decades, factors like coal mining had drastically reduced the usability of stream water in the region; as such, an attempt has been made to assess the spatiotemporal variation of stream water chemistry affected by acid mine drainage (AMD) at Jaintia Hills, Meghalaya. The water variables were subjected to a multivariate statistical technique of principal component analysis (PCA) to understand their condition at each sampling point while comprehensive pollution index (CPI) and water quality index (WQI) was incorporated to assess the quality status. Maximum WQI was recorded in S4 (541.14) during summer, while minimum value was estimated in winter at S1 (14.65). Throughout the seasons, the WQI revealed "Good" quality in S1 (unimpacted stream), while the impacted streams (S2, S3, and S4) exhibited a "Very poor" to "Water unsuitable for drinking" status. Similarly, in S1, the CPI showed a ranged value of 0.20 to 0.37, presenting a water quality status of "Clean to Sub-Clean," whereas, CPI of the impacted streams indicated "Severely polluted" status. In addition, PCA bi-plot presented higher affinity of free CO2, Pb, SO42-, EC, Fe, and Zn in AMD-impacted streams than in unimpacted streams. The result demonstrates the environmental issues induced by coal mine waste and in particular, stream water being severely affected by AMD in mining areas of Jaintia Hills. Thus, measures to stabilized the mine repercussions and cumulative effects on the water bodies need to be formulated by the government, as stream water will remain the primary water source for the tribal communities in this region.

Salient ingredients for direct water reclamation from treated municipal wastewater for potable reuse: Diepsloot Township case study

Across the world population growth, expansion of economic activities and climate change have become a concern for future water supply. To address the issue, many countries are investigating strategies to augment current water supplies. Water reclamation has been identified as a plausible sustainable solution to meet potable water supply demand, in turn achieving SDG 6.3. This study identifies some of the critical success factors for consideration of municipal waste water reclamation. This was undertaken in the growing township of Diepsloot, in Johannesburg (South Africa). Diepsloot is densely populated with over 350,000 people as recorded in 2022. As a result, water shortages are common due to insufficient bulk water facilities to supply the area. A direct potable water reclamation plant from treated municipal wastewater has been proposed to augment the water supply. Aqueous Material Balance (AqMB)®, a process modelling simulator software for water treatment processes to predict water quality and quantity, was used to design and simulate the water reclamation plant process. Our findings show that, the quantity and quality of water, as well as the choice of treatment technology are key. The simulations treatment process proposed here-in indicated successful removal of the contaminants to acceptable SANS 241:2015 drinking water standards. The variation in seasonal feed data did not show any difference in the performance of the proposed process. Furthermore, the plant has the potential to provide 109 L/day of clean water per person for a population of 350,000. Therefore, direct potable water reclamation shows great potential to augment current water supply to support growing populations where natural water sources are scarce.

Study on Effective of Bacillus subtilis for Domestic Wastewater Treatment in the Royal Thai Army Chemical Department Area

Recently, wastewater has been discharged from various sources into natural water sources, causing them to be contaminated with waste. Therefore, this study concentrates on guidelines for utilizing Bacillus Subtilis for wastewater treatment in the pond in front of the Science Division, Department of Army Science, which collects wastewater from office buildings and accommodations within the Royal Thai Army Science Department and discharges it to the public canal. Therefore, water must be treated before discharge. Samples were collected from a pond in front of the Science Division and a pond in front of the Pyro building for bacterial isolation (two soil samples and two water samples). The isolated and purified bacteria were used for preliminary morphological studies. All the isolated bacteria were gram-negative bacteria with 21 endospores. Protein, starch, and lipid degradation enzymes were tested using selected foods, namely skimmed milk agar, starch agar, and Tween 80 agar, and the point inoculation technique was applied. The results revealed that the isolates KCT03, KCT04, and KCT05 could produce these three groups of enzymes. The antagonism of the isolated bacteria was tested, and it was found that the three species were not antagonistic. All three samples were classified as bacteria, and KCT03 and KCT05 were found to be Bacillus subtilis. The efficiency of microbial wastewater treatment was tested at the laboratory level, and the experiment was planned to be a completely randomized design (CRD) consisting of three experimental sets and three repetitions to measure the water quality, pH, COD, BOD, TSS, TDS, oil, and fat. It was found that KCT03 was the best wastewater treatment.

Bura ura, kendu waiyo (rain falls, water rises): the tyranny of water insecurity and an agenda for abolition in Kodi (Sumba Island, Indonesia)

This article explores the dynamic links between transformations in freshwater ecosystems and social changes in the Kodi region of Sumba (Indonesia). Insights into the politics surrounding changing hydrosocial systems are generated by using a feminist anthropology approach together with critical development studies and intersectionality theory. In aligning with fellow feminists whose advocacy sometimes takes the form of scholarship, I lay out a five-prong strategy for collecting empirical evidence from persons who are vulnerable when hydrological systems change and offer eight principles for future development interventions. The argument related to the five-prong toolkit is that by conducting intensive, extensive, opportunistic, and longitudinal research and by allying with grassroots interlocutors, interventions into water systems can be based on better evidence and can be socially just. Three stories about Kodinese interactions with water and experiences with change are at the heart of this article and lead to the formulation of consequential conclusions. In the first story, birth, death, and relocation intersect with changes in the type of reservoir and the tools and vehicles used to manage water. In the second story—the origin for “tyranny” in the subtitle—vulnerability to food and water scarcity emerges and is politicized when a river's flow is altered. In the third story—the basis for “abolition” in the subtitle—hydrological interventions perpetrated by extrinsic governments correlate to surveillance and incarceration by the military and paramilitary. One research finding is that interventions by extrinsic agencies into the hydrology of four connected watersheds have altered hydrosocial relationships. Another finding is that as water's routes shift, people adjust to new conditions with mixed outcomes. A third conclusion is water utilities have differential benefits within the Kodi community. Fourth, benefits from water development have dispersed along already existing lines within the social structure. Finally, intracultural differences related to intersectional identities coincide with variations in access to natural and developed sources of water.

Application of Citeromyces Siamensis for Molasses Wastewater Decolorization

Molasses is a brownish black viscous liquid produced in the last step of the cane sugar separating process. Molasses can be used in many industries, such as fertilizer production, animal husbandry, alcohol production, monosodium glutamate production, and acetic acid making. In Thailand, it is mainly used to produce alcohol and as animal feed. Molasses waste water is high in biochemical and chemical oxygen demand and suspended solids. If released into the environment without treatment, it will cause many environmental problems. Moreover, the molasses wastewater contains melanodin that is difficult to remove, which gives it a dark colour. The treated water, therefore, has a dark colour. If the treated water is released into a natural water source, it will cause the water to have an unusually dark colour. This research aims to study the optimum conditions for using Citeromyces siamensis microorganisms for biological disposal of wastewater. The experiment was conducted to find conditions that promote the reduction of the colour of molasses in wastewater. It has been found that the addition of 1 % glucose and 1 % peptone is more effective in decolourization by Citeromyces siamensis than the addition of other nutrients.

Impact of artificial waterholes on temporal partitioning in a carnivore guild: a comparison of activity patterns at artificial waterholes to roads and trails.

Temporal partitioning in large carnivores have previously been found to be one of the main factors enabling co-existence. While activity patterns have been investigated separately at artificial waterholes and e.g., game trails, simultaneous comparative analyses of activity patterns at artificial waterholes and game trails have not been attempted. In this study, camera trap data from Maremani Nature Reserve was used to investigate whether temporal partitioning existed in a carnivore guild of four species (spotted hyena, leopard, brown hyena and African wild dog). Specifically, we investigated temporal partitioning at artificial waterholes and on roads and trails an average of 1,412 m away from an artificial waterhole. Activity patterns for the same species at artificial waterholes and roads/game trails were also compared. We found no significant differences in temporal activity between species at artificial waterholes. Temporal partitioning on game trails and roads was only found between spotted hyena (nocturnal) and African wild dog (crepuscular). Between nocturnal species (spotted hyena and leopard) no temporal partitioning was exhibited. Only African wild dog exhibited significantly different activity patterns at waterholes and roads/game trails. This indicates artificial waterholes may be a location for conflict in a carnivore guild. Our study highlights the impact of anthropogenic landscape changes and management decisions on the temporal axis of carnivores. More data on activity patterns at natural water sources such as ephemeral pans are needed to properly assess the effect of artificial waterholes on temporal partitioning in a carnivore guild.

Impact of Climate Change on Gravity Flow Drinking Water Resource in the Upper Kosi Watershed, Lesser Himalaya

In the age of climate change, the hydrological cycle is the most sensitive cycle which is being adversely affected. The natural water sources such as natural springs, rivulets, rivers etc of non-glacial fed watershed in Uttarakhand are drying and dying steadily disturbing society’s economy, and environment and creating threat on livelihood and ecosystem of the region. The basic goal of the current paper is to evaluate the impact of climate change on the gravity flow drinking water resource of the study area, Lesser Himalaya, Uttarakhand. For this objective, the hydrometeorological data is analyzed in this paper. The meteorological data, i.e., mean temperature (y = 0.059x + (-) 102.07) and average annual rainfall (y = 2.759x + (-) 4546.41) shows an increasing trend while the hydrological data shows a decreasing trend over the time. The study shows that in spite of an increasing trend in the annual rainfall pattern, the groundwater resource has been depleted significantly in the study area caused by change in rainfall rhythm which has disturbed the water recharging capacity of soil into the aquifers and the baseflow discharge of the gravity flow sources. Due to all these changes, the baseflow water discharge capacity of gravity flow sources have perturbed badly which is imposing threat on drinking water supply in the villages of the study area. At present, there are 93 gravity flow drinking water schemes in the study area. On an average, the baseflow water discharge of these schemes at their establishment year was recorded 40.11 l/m which has decreased to 23.46 l/m in 2018. Thus, on an average, about 16.65 l/m baseflow water discharge capacity of each scheme has been decreased since their establishment year. These data shows that how alarmingly the baseflow water discharge capacity at the sources of gravity flow schemes is depleting in the study area. Therefore, the study suggests a water source rejuvenation program for the sustenance of water sources, livelihood and ecosystem of the region.

Performance evaluation and conservation of waste solid plastics into alternative fuel for a pollution‐free environment

AbstractThe handling of waste plastics is a big challenge and various recycling routes are imposed to prevent the environmental ecosystem. Waste plastics are one of the major pollutants in the living environment and have characteristics such as non‐dehydration and toxicity. The wastages are occupying natural lands and water source areas, decreasing the soil behavior, reducing the minerals, and affecting the environmental ecosystem. In this situation, waste plastics are effectively handled with a suitable recycling process that helps to minimize toxicity. According to the present research, waste plastics are handled by separate arrangements and treated with the pyrolysis technique to obtain useful alternative fuel oil for automotive fuel applications. The synthesized pyrolysis (waste plastic oil fuel) oil fuel is tested by single stage four‐stroke diesel engines and its performance is compared with standard diesel fuel. The test results show that the brake thermal efficiency is improved by 28.85%. A higher 37% yield was obtained during this decomposition process above the 550°C temperature of 1 kg of waste plastics, formed as gas and condensed via cooling water, maintaining an ambient temperature. Moreover, the DI gas emission analyzer is used to evaluate the exhaust gas emission result found less than 1% of the CO and HC formation.

Population estimate and conservation status of the Persian Leopard, Panthera pardus tulliana, in the Bamo and Khoshk Mountains in Kurdistan Region, northern Iraq

In Iraq, the endangered Persian Leopard (Panthera pardus tulliana) is distributed in the northern part (Kurdistan Region) along the Zagros mountain steppe ecoregion, which includes the Bamo and Khoshk Mountains, where we carried out a field survey between October 2020 and November 2022 including camera trapping and interviews with local communities. At least five individuals were recorded during this study, including males, a female, and a family, given a population density of 1.25 indivuduals/100 km2. Bezoar Goat and Wild Boar are their key prey species in the area. Poaching and wildlife trafficking, decreasing natural water sources, overgrazing, minefields, and forest fires are identified as key threats facing the Persian Leopard population, their prey species, and their natural habitats in the Bamo and Khoshk Mountains. It is suggested to designate the study area as a national protected area or a transboundary conservation area between Iraq and Iran.

Detection of vertebrates from natural and artificial inland water bodies in a semi-arid habitat using eDNA from filtered, swept, and sediment samples.

Biomonitoring is vital for establishing baseline data that is needed to identify and quantify ecological change and to inform management and conservation activities. However, biomonitoring and biodiversity assessment in arid environments, which are predicted to cover 56% of the Earth's land surface by 2100, can be prohibitively time consuming, expensive, and logistically challenging due to their often remote and inhospitable nature. Sampling of environmental DNA (eDNA) coupled with high-throughput sequencing is an emerging biodiversity assessment method. Here we explore the application of eDNA metabarcoding and various sampling approaches to estimate vertebrate richness and assemblage at human-constructed and natural water sources in a semi-arid region of Western Australia. Three sampling methods: sediment samples, filtering through a membrane with a pump, and membrane sweeping in the water body, were compared using two eDNA metabarcoding assays, 12S-V5 and 16smam, for 120 eDNA samples collected from four gnammas (gnamma: Australian Indigenous Noongar language term-granite rock pools) and four cattle troughs in the Great Western Woodlands, Western Australia. We detected higher vertebrate richness in samples from cattle troughs and found differences between assemblages detected in gnammas (more birds and amphibians) and cattle troughs (more mammals, including feral taxa). Total vertebrate richness was not different between swept and filtered samples, but all sampling methods yielded different assemblages. Our findings indicate that eDNA surveys in arid lands will benefit from collecting multiple samples at multiple water sources to avoid underestimating vertebrate richness. The high concentration of eDNA in small, isolated water bodies permits the use of sweep sampling that simplifies sample collection, processing, and storage, particularly when assessing vertebrate biodiversity across large spatial scales.

Prediction of Land Use Change in Catchment Area of Buttu Batu DAM, South Sulawesi Indonesia

Land use change is generally caused for social, economic, and cultural reasons. Still, it has occurred not only in urban areas but almost all areas, such as upstream watersheds or catchment areas. Land use is a natural resource influenced by soil, climate, topography, and geology that determine the potential for various uses such as natural water sources, agriculture, transportation, and renewable energy. So this study aims to look at changes in land use and factors that influence these changes. The regional boundary is in the form of the Batu-Batu catchment area as the location of the hydropower dam with a capacity of 2x100 megawatts. It is planned to be built. The geographic information system (gis) is used to see land use changes. Land use projections use cellular automata analysis by looking atgrowth trends and targets on landusesimsoftware.landusesim begins with the neighborly process by entering and managing landuse data as an initial transition map into a potential transition map.The catchment areabuttu batu,which affects the dam plan, has an area of 371,191.77 ha. The existing catchment area of buttu batu is dominated by dryland agricultural land in the form of seasonal crops. Land use projections for 100 years see changes in land use area in several classes, the largest occurring in the land use of dryland agricultural areas with an area of 26,092.24 ha or an increase of 94.78%. Landuse in the form of settlements also increased by 3,223.44 ha or with a percentage change of 5.22 percent. Factors influencing land change in the catchment area include road access, settlement, and riverdistance.

Chitosan flakes-mediated diatom harvesting from natural water sources.

Diatom is a unicellular photosynthetic microalga that is found in diverse environments. These are decorated with siliceous cell walls called frustules. Diatoms have long been favoured by grazers such as microscopic protozoa and dinoflagellates. However, grazers typically remain intact in laboratory culturing and feed on diatom in culturing vessels and reducing biomass yield. The isolation and cultivation of diatoms in laboratories hamper diatoms' diversity and vast industrial potential. Chitosan, a biopolymer, has been widely used with other polyelectrolytes to flocculate various organic and inorganic colloids at acidic pH. Dissolved chitosan (acidic pH) has been used in various natural water samples and wastewater system for dewatering. However, untreated chitosan flakes have never been evaluated in a heterogeneous natural water environment. Since diatoms have silica surfaces, we tested chitosan for diatom separation and optimized chitosan concentration and other parameters to obtain grazer-free diatom starter culture from raw water. We also elucidated the mechanism for chitosan flakes-mediated diatom flocculation through adsorption kinetics and molecular dynamic simulation analysis. The results of this study are statistically optimized and validated, with a significant R2 value of 0.99 for the proposed model.

The role of climate change and niche shifts in divergent range dynamics of a sister-species pair.

Species ranges are set by limitations in factors including climate tolerances, habitat use, and dispersal abilities. Understanding the factors governing species range dynamics remains a challenge that is ever more important in our rapidly changing world. Species ranges can shift if environmental changes affect available habitat, or if the niche or habitat connectivity of a species changes. We tested how changes in habitat availability, niche, or habitat connectivity could contribute to divergent range dynamics in a sister-species pair. The great-tailed grackle (Quiscalus mexicanus) has expanded its range northward from Texas to Nebraska in the past 40 years, while its closest relative, the boattailed grackle (Quiscalus major), has remained tied to the coasts of the Atlantic Ocean and the Gulf of Mexico as well as the interior of Florida. We created species distribution and connectivity models trained on citizen science data from 1970-1979 and 2010-2019 to determine how the availability of habitat, the types of habitat occupied, and range-wide connectivity have changed for both species. We found that the two species occupy distinct habitats and that the great-tailed grackle has shifted to occupy a larger breadth of urban, arid environments farther from natural water sources. Meanwhile, the boattailed grackle has remained limited to warm, wet, coastal environments. We found no evidence that changes in habitat connectivity affected the ranges of either species. Overall, our results suggest that the great-tailed grackle has shifted its realized niche as part of its rapid range expansion, while the range dynamics of the boat-tailed grackle may be shaped more by climate change. The expansion in habitats occupied by the great-tailed grackle is consistent with observations that species with high behavioral flexibility can rapidly expand their geographic range by using human-altered habitat. This investigation identifies how opposite responses to anthropogenic change could drive divergent range dynamics, elucidating the factors that have and will continue to shape species ranges.

Polybrominated diphenyl ethers in water, suspended particulate matter, and sediment of reservoirs and their tributaries in Shenzhen, a mega city in South China.

Urban reservoirs serve many purposes including recreation and drinking water, and larger bodies of water can alter the surrounding air temperatures, making urban areas cooler in summer and warmer in winter. However, reservoirs may also be sinks for contaminants. One such group of contaminants, the polybrominated diphenyl ethers (PBDEs), are persistent organic pollutants known to accumulate in sediments and suspended particulate matter (SPM). Few studies have been conducted on PBDEs in water, SPM, and sediment from reservoirs of Shenzhen which is a mega city in South China. To this end, 12 PBDEs were measured in water, SPM, and sediment samples during the dry season (DS) and wet season (WS), to explain the spatiotemporal distribution, congener profiles, sources, and risks of pollutants in four reservoirs (A-D) and their tributaries in the study region. The concentration of ∑12PBDEs during the DS was found to be significantly higher than that during the WS. Source apportionment suggested that commercial penta-, octa-, and deca-BDEs are the major components of PBDEs, resulting mainly from atmospheric deposition, wastewater discharge, and external water-diversion projects. Further, attention should be paid to electronic equipment manufacturing factories in the study area. Risk assessment indicated risk of PBDEs (especially BDE-209) in sediment and SPM to be of concern. This study provides important data support for the control of PBDEs in natural drinking water sources.