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[Display omitted] • Barriers to microalgal mass cultivation depend on the value of the final product. • Low value products such as biofuels have the greatest barriers to production. • Different cultivation systems and strategies present a subset of barriers. Economically successful microalgal mass cultivation is dependent on overcoming several barriers that contribute to the cost of production. The severity of these barriers is dependent on the market value of the final product. These barriers prevent the commercially viable production of algal biofuels but are also faced by any producers of any algal product. General barriers include the cost of water and limits on recycling, costs and recycling of nutrients, CO 2 utilization, energy costs associated with harvesting and biomass loss due to biocontamination and pond crashes. In this paper, recent advances in overcoming these barriers are discussed. [ABSTRACT FROM AUTHOR]

This paper describes a forensic investigation of groundwater in an urban context in Italy. The present case study was conducted to detect the hydraulic flow path between a sportfishing pond and a nearby industrial plant's contaminated groundwater site. The investigation was performed to evaluate the potential for diffusion of contaminants through groundwater flow into a fishing pond located downstream from a chemical factory. High-precision altitude measurements of monitoring stations combined with continuous water level monitoring were crucial to understand the groundwater flow dynamics and define the hydrogeological conceptual model. The study verified that the fishing pond, dug in low-permeability volcanic rock, was not hydraulically connected to the groundwater flow. The presence of contaminants in the pond may be related to the periodic topping-up activity performed using water from an existing well. The identified groundwater flow paths were consistent with the possible contaminant migration from the chemical factory to the water well near the fishing pond. [ABSTRACT FROM AUTHOR]

The main sources of water resources of the Barak Valley of Northeast India for irrigation are the surface water bodies in the form of ponds, lakes, rivers, and groundwater. This paper elucidates insight into the irrigational parameters to classify the types of water, based on these indices. Total hardness shows that 90% of surface water belongs to the soft and 63% of groundwater samples belong to the soft category. C‐S plot shows 33% of surface water belongs to C1‐S1 and 66% of groundwater samples belongs to C1‐S1 and C2‐S1, indicating fresh and suitable for use. The percentage Na+ shows most samples belong to good and permissible categories. Permeability index shows 81% of surface water in Class II and 18% in Class III, indicating good and bad types, respectively. Kelly's index suggests 90% of surface water is suitable and 9% is unsuitable, while 14% of piedmont groundwater is unsuitable. Magnesium hazard reveals 18% of surface water has more than 50 Magnesium absorptio ratio, leading to unsuitable, while 28% of piedmont and 33% of flood plain groundwater samples belong to unsuitable. Residual sodium carbon suggests surface water as suitable, while 48%, 12%, and 6% of groundwater belong to suitable, marginal, and unsuitable categories, respectively. Irrigation Water Quality Index values indicate that surface water is characterized by a highly restricted class, as they are exposed to surficial contamination as compared to groundwater. Base exchange index of ions indicates Na+‐SO4−2 hydro‐facies type suggesting dissolution of salt minerals in weak acidic water. Meteoric genesis index of ions reveals the source of groundwater as deeper meteoric water. Thus, the present study indices that the surface water bodies such as ponds, lakes, and swamps are more prone to contamination, leading to unsuitability for irrigational use, as compared to shallow groundwater in the study area, and therefore, appropriate measures must be adopted to reduce the quality deterioration for maximum utilization. [ABSTRACT FROM AUTHOR]

Although social-ecological fisheries research is growing, comparatively little attention is paid to fisheries in urban environments. We aim to address this imbalance, because as cities expand worldwide, we expect urban fisheries to become more widespread and important in providing food/nutrition security, recreation, community well-being, and other benefits to fisheries stakeholders and urban dwellers across spatiotemporal scales. This paper contains a first analysis of the economic and sociocultural provisions, trade-offs, and dilemmas associated with urban fisheries to yield insights for sustainable management and planning of urban blue space. To address these objectives, we use the metacoupling framework, a method for assessing human–nature interactions within and across adjacent and distant fisheries systems. We use examples from multiple countries and data from the United States to illustrate how urban fisheries encompass flows of people, money, and information across multiple spatiotemporal scales and provide nutritional, recreational, social, and cultural benefits to fisheries stakeholders. Throughout the world, urban fisheries are influenced by wide-ranging human needs (e.g. food provisioning, recreation, aquatic resource education) that generate social-ecological effects within and beyond cities. Our analysis yields insights for developing holistic, metacoupling-informed management approaches that address the diverse social-ecological objectives and trade-offs involved in sustainable development of urban fisheries. [ABSTRACT FROM AUTHOR]

The article attempts to define and determine the intangible components of cultural heritage related to the spatial structure of land in a comprehensive way using computational methods. The components were quantified and a method of empirical evaluation of landscape durability was proposed for agricultural areas of significant cultural and historical value with an evident mosaic structure of fields, baulks, ponds, meadows, and forests. This method allows us to identify places more resistant to political transformation and those with greater cultural potential. The paper proposed an integrated approach to the measuring of the degree of preservation of spatial arrangements in the landscape based on a set of objects that describe the spatial land structure. The article classifies areas by the degree of preservation of rural spatial arrangements of land. The spatial analysis employed facilitated a synthetic quantification of the multi-criteria process. Three groups of factors were used: spatial assessment of land-cover type persistence (u), agricultural land structure persistence (w), and persistence of settlement buildings (z). The final results pinpointed areas in need of strategic intervention to sufficiently protect the rural cultural heritage, properly consider them in zoning planning, and ensure their sustainable development. The proposed tool can be used to monitor the degree of changes in the landscape layout structure when multiple time points are analysed as well. [ABSTRACT FROM AUTHOR]

The article presents an overview of a research by Jonathon J. Ledford and Anita M. Kelly that won the Best Paper in the "North American Journal of Aquaculture" in 2007. They aimed to test the use of black carp to remove parasite-carrying snails in farmed channel catfish ponds. The researchers tested various sizes of redear sunfish, blue catfish and black carp to determine their snail munching abilities. They found that black carp consumed most of the snails due to their large mouth size and crushing molars.

The appropriate design of the pond coast structures and the reservoir supplement management entails an accurate pond water surface simulation. A hybrid Genetic Algorithm - Artificial Neural Network (GA-ANN) is presented and applied in this research to estimate the next 3- and 5-day water surfaces. Training and validation of the GAANN is performed using the 4-year daily water surface measurements performed on Chahnimeh reservoir located on the eastern side of Iran. Various input combinations are applied to the GA-ANN method. According to the results, for both the next 3- and 5-day estimation models, the input combination, consisting of the past 2-day water surface data, contributes to the optimal yield. Root Mean Squared Error of the optimum next 3- and 5-day prediction GA-ANN models were obtained to be 0.1798 and 0.3102, respectively. This paper found that in modelling the 3- and 5-day ahead pond water level, the best input variables are the information on the one and two previous days. [ABSTRACT FROM AUTHOR]

• Process-based environmental fate model (PESTIPOND) for dissolved pesticides is developed & tested. • PESTIPOND integrates a hydrological sub-model and the key transport, transfer, and transformation processes of dissolved pesticides in APs. • Sensitivity analysis underlines that sorption, biotransformation, and photolysis are the governing processes behind pesticide fate in APs. • PESTIPOND is designed to be integrated into surface water assessment tools to predict pesticide behavior at the watershed scale. Some artificial ponds (APs) are designed to collect part of the agricultural water fluxes and dissipate their pesticide contamination through a synergy of physicochemical processes. As part of a two-paper series, this paper describes the development of PESTIPOND, a process-based model for pesticide fate in AP. PESTIPOND comprises a hydrological model and a pesticide transfer model. A test-case simulation shows that PESTIPOND can predict the mass dynamics of different pesticides within AP compartments. Sensitivity analysis evidenced that adsorption–desorption, biotransformation, and photolysis have the most significant impact on the behavior of dissolved pesticides in APs. PESTIPOND is a promising tool for better understanding the performance of ponds and can help improve AP's efficiency in preserving water quality. A second paper addresses the application of PESTIPOND in a real-case scenario and its validation (Bahi et al., 2023a). The model can thus be integrated into landscape modeling tools (e.g., surface water assessment tools) to predict pesticide transfer at the watershed scale. [ABSTRACT FROM AUTHOR]

• Time-dependent environmental fate model (PESTIPOND) for dissolved pesticides is developed and validated. • Model accurately predicts concentrations after episodic pesticide applications. • Model quantifies the mass partition of dissolved pesticides in the water and sediments of ponds. • Model estimates the contribution of each key process behind pesticide dissipation in artificial ponds. • PESTIPOND is freely available for use and further study. Some artificial ponds (APs) are designed to collect part of the agricultural water fluxes and dissipate pesticide contamination through a synergy of physicochemical processes. APs act as buffer zones and mitigate pesticide transfer of farm plots to natural water resources. As part of a two-paper series, this paper addresses the application and validation of the PESTIPOND model. PESTIPOND is a process-based model developed to predict pesticides' behavior and distribution in APs located in drained agricultural catchments. Paper I (Bahi et al., 2023a) describes the development and sensitivity analysis of the model. PESTIPOND was applied on the Rampillon AP to characterize the fate of seven different pesticides and five monitoring periods while considering the key transfer and transformation processes. The model was assessed through various methods against the observed data in simulating pesticide dynamics. The statistical and graphical evaluation of PESTIPOND reflected a good performance except for boscalid. The sensitivity analysis and application of the model evidenced that adsorption-desorption and biotransformation in the pond water are major processes behind pesticide dissipation. Hydrophobic and lowly mobile pesticides are more likely to be bio-transformed at the water-sediment interface. This work highlights the link between the hydraulic residential time (HRT), temperature, and APs' efficiency in minimizing pesticide transfer into the environment. The model predicted that the actual efficiency of the AP covering 0.15% of the drained catchment would double if the pond's surface area covered at least 1% of the catchment. Moreover, the model's predictions evidenced that a temperature rise of 10 °C will increase the dissipation of pesticides by only 8%. PESTIPOND provides key elements that are useful to design and manage ponds with optimal efficiency. Hence, these APs can be complementary solutions to pesticide use regulation to reduce the transfer of agricultural contamination into freshwater resources. [ABSTRACT FROM AUTHOR]

Tailings ponds, large man-made structures conceived during the mining process for waste storage, often become deserted post-mining, leaving behind a stark, contaminated landscape. This paper posits that these forsaken tailings ponds can be rejuvenated into fertile agricultural land through adept reclamation efforts. Serving as a discussion paper, it engages in a stimulating exploration of the environmental and health risks linked to tailings ponds. It sheds light on the potential and impediments in the transformation of these ponds into agricultural land. The discussion concludes that despite the substantial hurdles in repurposing tailings ponds for agriculture, there are encouraging prospects with the application of multifaceted efforts. • This paper explores the potential of transforming these abandoned tailings ponds into productive agricultural land. • This paper explores the environmental risks of tailings ponds and the difficulties and potentials in their restoration. • This paper underpins the importance of land reclamation in addressing issues of land contamination and food security. [ABSTRACT FROM AUTHOR]

The Glastir Monitoring and Evaluation Programme (GMEP) ran from 2013 until 2016 and was probably the most comprehensive programme of ecological study ever undertaken at a national scale in Wales. The programme aimed to (1) set up an evaluation of the environmental effects of the Glastir agri-environment scheme and (2) quantify environmental status and trends across the wider countryside of Wales. The focus was on outcomes for climate change mitigation, biodiversity, soil and water quality, woodland expansion, and cultural landscapes. As such, GMEP included a large field-survey component, collecting data on a range of elements including vegetation, land cover and use, soils, freshwaters, birds, and insect pollinators from up to three-hundred 1 km survey squares throughout Wales. The field survey capitalised upon the UK Centre for Ecology & Hydrology (UKCEH) Countryside Survey of Great Britain, which has provided an extensive set of repeated, standardised ecological measurements since 1978. The design of both GMEP and the UKCEH Countryside Survey involved stratified-random sampling of squares from a 1 km grid, ensuring proportional representation from land classes with distinct climate, geology and physical geography. Data were collected from different land cover types and landscape features by trained professional surveyors, following standardised and published protocols. Thus, GMEP was designed so that surveys could be repeated at regular intervals to monitor the Welsh environment, including the impacts of agri-environment interventions. One such repeat survey is scheduled for 2021 under the Environment and Rural Affairs Monitoring & Modelling Programme (ERAMMP). Data from GMEP have been used to address many applied policy questions, but there is major potential for further analyses. The precise locations of data collection are not publicly available, largely for reasons of landowner confidentiality. However, the wide variety of available datasets can be (1) analysed at coarse spatial resolutions and (2) linked to each other based on square-level and plot-level identifiers, allowing exploration of relationships, trade-offs and synergies. This paper describes the key sets of raw data arising from the field survey at co-located sites (2013 to 2016). Data from each of these survey elements are available with the following digital object identifiers (DOIs): Landscape features (Maskell et al., 2020a–c), https://doi.org/10.5285/82c63533-529e-47b9-8e78-51b27028cc7f , https://doi.org/10.5285/9f8d9cc6-b552-4c8b-af09-e92743cdd3de , https://doi.org/10.5285/f481c6bf-5774-4df8-8776-c4d7bf059d40 ; Vegetation plots (Smart et al., 2020), https://doi.org/10.5285/71d3619c-4439-4c9e-84dc-3ca873d7f5cc ; Topsoil physico-chemical properties (Robinson et al., 2019), https://doi.org/10.5285/0fa51dc6-1537-4ad6-9d06-e476c137ed09 ; Topsoil meso-fauna (Keith et al., 2019), https://doi.org/10.5285/1c5cf317-2f03-4fef-b060-9eccbb4d9c21 ; Topsoil particle size distribution (Lebron et al., 2020), https://doi.org/10.5285/d6c3cc3c-a7b7-48b2-9e61-d07454639656 ; Headwater stream quality metrics (Scarlett et al., 2020a), https://doi.org/10.5285/e305fa80-3d38-4576-beef-f6546fad5d45 ; Pond quality metrics (Scarlett et al., 2020b), https://doi.org/10.5285/687b38d3-2278-41a0-9317-2c7595d6b882 ; Insect pollinator and flower data (Botham et al., 2020), https://doi.org/10.5285/3c8f4e46-bf6c-4ea1-9340-571fede26ee8 ; and Bird counts (Siriwardena et al., 2020), https://doi.org/10.5285/31da0a94-62be-47b3-b76e-4bdef3037360. [ABSTRACT FROM AUTHOR]

Pond irrigation water comprises a major pathway of pathogenic bacteria to fresh produce. Current regulatory methods have been shown to be ineffective in assessing this risk when variability of bacterial concentrations is large. This paper proposes using mechanistic modeling of bacterial transport as a way to identify improved strategies for mitigating this risk pathway. If the mechanistic model is successfully tested against observed data, global sensitivity analysis (GSA) can identify important mechanisms to inform alternative, preventive bacterial control practices. Model development favored parsimony and prediction of peak bacterial concentration events. Data from two highly variable surface water irrigation ponds showed that the model performance was similar or superior to that of existing pathogen transport models, with a Nash-Sutcliffe efficiency of 0.48 and 0.18 for the two ponds. GSA quantified bacterial sourcing and hydrology as the most important processes driving pond bacterial contamination events. Model analysis has two main implications for improved regulatory methods: that peak concentration events are associated with runoff-producing rainfall events and that intercepting bacterial runoff transport may be the best option to prevent bacterial contamination of surface water irrigation ponds and thus fresh produce. This research suggests the need for temporal management strategies. IMPORTANCE Preventive management of agricultural waters requires understanding of the drivers of bacterial contamination events. We propose mechanistic modeling as a way forward to understand and predict such events and have developed and tested a parsimonious model for rain-driven surface runoff contributing to generic Escherichia coli contamination of irrigation ponds in Central Florida. While the model was able to predict the timing of peak events reasonably well, the highly variable magnitude of the peaks was less well predicted. This indicates the need to collect more data on the fecal contamination inputs of these ponds and the use of mechanistic modeling and global sensitivity analysis to identify the most important data needs. [ABSTRACT FROM AUTHOR]

In this paper, a qualitative safety analysis of the Żelazny Most tailings pond is addressed. This object is one of the largest facilities of this type in the world being a crucial element in the technological line of copper production in KGHM Polska Miedź S.A. The assessment of the effectiveness of two types of preventive measures, i.e., relief wells and loading berms, is investigated based on displacement and stability analysis of two 2D cross-sections in a technical section of the dam. The study shows that the considered preventive measures generally have a positive impact on increasing the safety level of the structure during its further raise. In particular, their effectiveness is most evident when they are applied simultaneously. It is eventually suggested that the selection of final solutions to be applied on the facility should be based on the quantitative 3D analysis. [ABSTRACT FROM AUTHOR]

• Stepwise improved biophysical model is reusable for reduced and extended cases. • The studied food web models are sensitive to initial concentrations of plankton. • Model improvement requires parallel measurements to decrease sampling errors. • Programmable Process Structure serves as an extensible method to support reuse. • Reusability check contributes to the development of scaling-up and planning models. Given the increasing importance of data- and model-driven design and control in food production systems, this paper addresses the need to improve the reproducibility, replicability, and reusability of datasets, models, and modeling frameworks. While sensor data and machine learning-based control and operation of agricultural and aquacultural systems face reproducibility and replicability challenges, reusability is becoming critical for computational model-based design and planning of complex processes. This study evaluates the reusability of an existing pond aquaculture model and outlines a systematic, stepwise approach for reusability enhancements. The suggested methodology starts with an established reference model of a typical production fishpond and improves its reusability through pilot-scale experiments, covering key aspects of pond farming technologies. The reference model is subjected to stepwise reusability checks using measured data from the respective pilot units, progressing from simpler (reduced) to more complex (extended) cases. Each step concludes with the necessary parameter or sub-model refinements, which remain unchanged in subsequent steps. The refined model is validated with the measured data from other pilot experiments. This process can be repeated until satisfactory results are obtained. The resulting model is then tested to scale up a production pond model using limited case-specific input data. In addition, a hypothetically modified scenario is studied to address discrepancies between measured and simulated data. [ABSTRACT FROM AUTHOR]

The paper is concerned with the results of 137Cs monitoring in the irrigation ponds of the Okuma town in the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) exclusion zone. The 137Cs activity concentrations in the ponds appeared to be higher than those in the rivers and dam reservoirs in the region. The study has revealed a trend for a decline in 137Cs activity concentrations, both particulate and dissolved. The rate of particulate 137Cs decline was much higher than that of dissolved. The total distribution coefficient ) in the suspended sediment–water system in the studied ponds was decreasing in time with the rate constant of 0.12–0.18 year–1. Assuming that the decrease in is associated with decomposition of hot glassy particles, the time scale of 137Cs leaching from them in these water bodies was estimated to be 5–8 years. These estimates are consistent with the findings of recent laboratory experiments on the subject. With respect to seasonal variations, the highest levels of dissolved 137Cs in the studied ponds were observed from June to October as a function of specific pond and monitoring year. Based on data about 137Cs speciation in the bottom sediment top layer of the ponds and its distribution in the sediment–water system, the exchangeable radiocesium interception potential for the ponds sediments was estimated to be 1650–2250 mg-eq/kg, which is within the range of values measured by laboratory studies. [ABSTRACT FROM AUTHOR]

The spatially hierarchical stream hydrogeomorphology classification presented by Cox et al. ([3]), based on 42 Irish headwater streams, is simple to apply and may be applicable across northern and western Europe with similar climate - landscape conditions. It is clear from these papers and others presented at SEFS12 that the extensive length of the small stream network and high numbers of ponds poses challenges in terms of water quality and biodiversity monitoring. Small water bodies are increasingly recognised as important for biodiversity and in terms of their influence on downstream water quality and contributions to catchment ecosystem services (Riley et al., [12]). [Extracted from the article]

Drainage ditches, which are abundant in the southern river network area, provide drainage services for farmland and are also valuable resources for reducing agricultural pollutants as well as providing habitats for wildlife. It is really a precious natural resource. However, since ditches also occupy part of the land resources, and hindered the mechanization of operations. There is a certain contradiction between mechanical operation and the development of modern agriculture. How to balance various needs in rural ecological construction and protection has become an urgent scientific problem to be solved. Based on a typical case, according to the different emphasis of environmental protection and land increase, this paper analyzed the optimization of ditches/ponds protection while calculating the benefit change in different scenarios, and considered some difficult-to-quantify factors to explore the best transformation mode of the ditches and ponds. The existing ditches/ponds area in this study is 0.82 hm2, accounting for 14.3% of the farmland, of which the proportions of ponds, branch ditches and farms are 28%, 60% and 12%, respectively. The results of economic analysis show that according to the current land lease price, the economic benefits of reducing the area of the ditches/ponds and increasing the land use are higher than those of the ditches and ponds in terms of pollutant removal and ecological pest control. In combination with other factors that are difficult to quantify, this paper recommends that the branch ditches, which are distributed along the edges of the plots and have large area, should be reserved in order to maintain the original drainage and ecological environment functions while ensuring less impact on the field mechanical operations. For densely distributed and small size ditches, it is recommended to use drainage tube instead, which can minimize the impact on the field mechanization operation and reduce the impact on the ecological environment; For those larger and unevenly distributed ponds, considering their small population and limited impact on farmland drainage, can be reclaimed for reclamation on the basis of well-drained drainage facilities. For the study area, the above proposal will reduce the total area of the ponds from 8 020 m2 to 4 818 m2, reduce the area ratio of farmland from 14.3% to 8.6%, and the comprehensive economic benefit ratio can be increased from the current 5 217 to 6 740 RMB; however, the pollutants removal and pest control role will be reduced from the current 5 217 to 3 134 RMB, while the land rental income increases to 3 606 RMB. Therefore, simply from an economic point of view, the benefits of increasing land area should be higher than the economic benefits of reduced pollutant reduction and pest control. If the land proceeds increase in the future, the added value of land area will be more significant. Taking into account some difficult factors such as the provision of habitats and cultural landscape values, the protection and transformation of ditch pond systems in the future will also need to coordinate the demands and efforts of different departments. [ABSTRACT FROM AUTHOR]

Just how much change did Herzegovina go through over the last century, could be seen through abandoned stone edifice for water collection near the debris swallow-hole. Wells, tanks and ponds are an important source of information for the history of the people and area, but also for the history of architecture. Unfortunately, collections of many public wells, tanks and ponds are neglected or overgrown with weeds, and tanks are damaged or partially lumbered. We ought to rebuild our tanks and ponds not only for the sake of culture, history and tourist attractions but also for the sake of water preservation, because nowadays water is more precious than gold. This paper describes the architectural heritage along the springs and water that are part of the inherited heritage and evidence of the life in Herzegovina during the century. [ABSTRACT FROM AUTHOR]

We measured fluxes of methane, a suite of non-methane hydrocarbons (C2–C11), light alcohols, and carbon dioxide from oil and gas produced water storage and disposal ponds in Utah (Uinta Basin) and Wyoming (Upper Green River Basin) United States during 2013–2016. In this paper, we discuss the characteristics of produced water composition and air-water fluxes, with a focus on flux chamber measurements. In companion papers, we will (1) report on inverse modeling methods used to estimate emissions from produced water ponds, including comparisons with flux chamber measurements, and (2) discuss the development of mass transfer coefficients to estimate emissions and place emissions from produced water ponds in the context of all regional oil and gas-related emissions. Alcohols (made up mostly of methanol) were the most abundant organic compound group in produced water (91% of total volatile organic concentration, with upper and lower 95% confidence levels of 89 and 93%) but accounted for only 34% (28 to 41%) of total organic compound fluxes from produced water ponds. Non-methane hydrocarbons, which are much less water-soluble than methanol and less abundant in produced water, accounted for the majority of emitted organics. C6–C9 alkanes and aromatics dominated hydrocarbon fluxes, perhaps because lighter hydrocarbons had already volatilized from produced water prior to its arrival in storage or disposal ponds, while heavier hydrocarbons are less water soluble and less volatile. Fluxes of formaldehyde and other carbonyls were low (1% (1 to 2%) of total organic compound flux). The speciation and magnitude of fluxes varied strongly across the facilities measured and with the amount of time water had been exposed to the atmosphere. The presence or absence of ice also impacted fluxes. [ABSTRACT FROM AUTHOR]

Large tracts of mangroves have been converted into aquaculture ponds and the consequent loss of biodiversity has been much decried. This paper shows that high aquatic biodiversity is retained in mangrove-derived aquaculture ponds in Dumangas, Iloilo, Philippines. Documentation of biodiversity was carried out over two years in 15 adjacent ponds (water areas 0.25-0.9 ha) used for farming penaeid shrimps, mud crabs, milkfish, seabass, rabbitfish, and other fishes. At harvest, these ponds yielded many extraneous non-crop or "bycatch" species, which had been naturally seeded by the tides and had grown (and some species reproduced) over the 2-10 mo that the ponds were underwater. From 21 crop cycles were obtained 8-56 species (from 6-30 taxonomic families) of bycatch fishes and macrocrustaceans with biomass of 2.5-168.4 kg ha-1 and abundance of 2-92 x 10³ individuals ha-1, the differences due to pond area, duration of immersion, farming system, crop species, and the bycatch community. Some 85 species (44 families) of fishes occurred in the ponds, including 12 species of gobies, of which the small-size Acentrogobius viganensis, Pseudogobius javanicus, Mugilogobius cavifrons, and Gobiopterus panayensis reached high abundance. Macrocrustaceans consisted of 30 species (nine families), including several penaeid and palaemonid shrimps (Metapenaeus ensis and Nematopalaemon tenuipes were most common) and portunid and grapsid crabs. Mollusks in the ponds included 58 species (24 families), of which Cerithideopsilla cingulata was most abundant. The Dumangas ponds were leaky and allowed tidal recruitment of many mangrove animals despite net screens and chemical treatments. Existing tidal ponds serve as proxy mangrove lagoons (wetlands) that can harbor high aquatic biodiversity. [ABSTRACT FROM AUTHOR]

The growing aquaculture industry is facing several challenges including risks and uncertainties. Studies exploring farmers' risk perceptions and risk management strategies are, however, limited within pond aquaculture, although they are well described within the field of agriculture. This study explores farmers' risk perceptions and risk management strategies in pond aquaculture and the relationship of risk perceptions and risk management strategies with farm and farmers' characteristics. The data are analyzed using principal component analysis and multivariate regression. The results show that price variability and financial risks are perceived as the most influential risk factors. Farm management and financing are perceived as the most effective risk management strategies. In most cases, farmers need to focus on more than one risk management strategy to address a particular type of risk. This study provides knowledge of farmers' risk perceptions and strategies, which can be used to develop better and more focused management strategies. The authors would like to thank three anonymous reviewers for their suggestions and comments that helped substantially to improve the paper. The authors would also like to thank the Danish International Development Agency (DANIDA) for its financial support for the project "Upgrading Pangas and Tilapia Value Chains in Bangladesh," project number F38A26778, under which this research was conducted. [ABSTRACT FROM AUTHOR]

The constant dynamic changes in salt pond make it difficult to achieve accurate prediction of ion concentration. It is of great significance to get the accurate prediction of potassium ion concentration in salt pools for the actual production of potash fertilizer. In this paper, some machine learning methods, such as support vector regression (SVR), AdaBoost regressor, K neighbor regressor, gradient boosting regressor, extra trees regressor and neural network regressor, have been used to build the prediction models. In the experiment, the MSE and R2 of the K+ concentration by using SVR in test data set reach 0.26385 and 0.9414, which are better than other models. Therefore, the SVR model has high research value in the field of salt pool ion concentration prediction. [ABSTRACT FROM AUTHOR]

Coal ash ponds or lagoons are surface impoundments constructed to store the unused coal ash generated from thermal power plants. In India, by the end of 2020 nearly 82,200 ha of land will be under ash ponds. Once the capacity of these ponds is reached, they are closed in compliance with the statutory regulations. Recent trends suggest that these lands could be reclaimed to accept light- to heavy-weight structures over them, which makes in situ characterization essential to ensure the safety of structures built over them. This paper presents the site characterization in terms of shear-wave velocity (Vs) of four hydraulically deposited coal ash lagoon sites (two existing and two abandoned) at two ash pond sites in India using the multichannel analysis of surface waves (MASW) technique. The ash is deposited using the wet slurry technique, and the age of deposition is found to have a significant effect on the shear-wave velocity of these deposits. An empirical correlation is presented between the mean Vs and depth (z) for all the sites considered. The measured Vs values were extrapolated using three different methods to obtain Vs,30 values, and the sites were classified as per the recommendations of the International Building Code. Standard penetration tests (SPTs) were conducted near the MASW testing locations at one of the abandoned ash ponds, and the SPT values (N values) had significant scatter. An empirical correlation is proposed between the mean Vs and N values obtained. [ABSTRACT FROM AUTHOR]

This paper investigates the capability of adaptive neuro-fuzzy inference system (ANFIS) and artificial neural network (ANN) modeling approach to predict the unconfined compressive strength (UCS) of stabilized pond ashes with lime alone and in combination with lime sludge. Out of 170 data set, a total of 119 data were randomly selected for training, whereas remaining 51 were used for testing the model. Four membership's functions (MFs) such as Gaussian, generalized bell-shaped, triangular, and trapezoidal were used with ANFIS model. Statistical parameters were used to compare the performance of four MF-based ANFIS and ANN models. A comparison of results suggests that Triangular MF-based ANFIS model exhibit better predictive performance with higher CC = 0.980 and lower MSE = 3028.515 and RMSE = 55.032 than other MF-based ANFIS and ANN model. The results of single-factor analysis of variance indicate that there is an insignificant difference between measured and predicted values of UCS using different models. Further, results of sensitivity analysis depict that the curing period, lime sludge, and lime are the most important parameters which affect the performance of Triangular MF-based ANFIS in predicting the UCS of stabilized pond ashes. Thus, the Triangular MF-based ANFIS model could be a useful tool in predicting the UCS value of stabilized pond ashes because of its adequacy in handling uncertainties in the test results with accuracy. [ABSTRACT FROM AUTHOR]

This paper aims to present the water quality index (WQI) made in the pond of the UNIVAP's treatment plant. Water quality index (IQA) is a classification parameter that can be obtained from the São Paulo State Sanitation Company (CETESB), which presents the optimal, good, regular and very poor classifications for each water course, lake, pond or river analyzed. The physical, chemical and biological parameters were compared to those stipulated by CONAMA Resolution 357/2005. [ABSTRACT FROM AUTHOR]

This paper reports on consolidated ground-based validation results of the atmospheric NO2 data produced operationally since April 2018 by the TROPOMI instrument on board of the ESA/EU Copernicus Sentinel-5 Precursor (S5p) satellite. Tropospheric, stratospheric, and total NO2 column data from S5p are compared to correlative measurements collected from, respectively, 19 Multi-Axis DOAS (MAX-DOAS), 26 NDACC Zenith-Scattered-Light DOAS (ZSL-DOAS), and 25 PGN/Pandora instruments distributed globally. The validation methodology gives special care to minimizing mismatch errors due to imperfect spatio-temporal co-location of the satellite and correlative data, e.g., by using tailored observation operators to account for differences in smoothing and in sampling of atmospheric structures and variability, and photochemical modelling to reduce diurnal cycle effects. Compared to the ground-based measurements, S5p data show, on an average: (i) a negative bias for the tropospheric column data, of typically -23 to -37% in clean to slightly polluted conditions, but reaching values as high as -51% over highly polluted areas; (ii) a slight negative bias for the stratospheric column data, of about -0.2Pmolec/cm2, i.e. approx. -2% in summer to -15% in winter; and (iii) a bias ranging from zero to -50% for the total column data, found to depend on the amplitude of the total NO2 column, with small to slightly positive bias values for columns below 6Pmolec/cm2 and negative values above. The dispersion between S5p and correlative measurements contains mostly random components, which remain within mission requirements for the stratospheric column data (0.5Pmolec/cm2), but exceed those for the tropospheric column data (0.7Pmolec/cm2). While a part of the biases and dispersion may be due to representativeness differences, it is known that errors in the S5p tropospheric columns exist due to shortcomings in the (horizontally coarse) a-priori profile representation in the TM5-MP chemistry transport model used in the S5p retrieval, and to a lesser extent, to the treatment of cloud effects. Although considerable differences (up to 2Pmolec/cm2 and more) are observed at single ground-pixel level, the near-real-time (NRTI) and off-line (OFFL) versions of the S5p NO2 operational data processor provide similar NO2 column values and validation results when globally averaged, with the NRTI values being on average 0.79% larger than the OFFL values. [ABSTRACT FROM AUTHOR]

In this paper, an automatic mesh generator is developed to simulate density-dependent water flow and transport problems in watershed systems. The two-dimensional (2D) triangular mesh is generated by global Delaunay triangulation, and the three-dimensional (3D) triangular-prism mesh is generated by vertical stretch. The implementation procedures of mesh generation are adjusted according to the interaction options of one-dimensional (1D) river, 2D overland, and 3D subsurface flows. An improved boundary point generation algorithm is proposed to maintain appropriate correspondence of points and edges according to the discrete patterns of river reaches and dead ends. Overlapped nodes are generated on zero-width river reaches and zero-width junctions without storage to construct the numerical models for 2D overland simulations. An additional triangular mesh generation method is proposed to create additional triangles for filling the empty water zones of finite-width river reaches, junctions with storage, finite-width ponds, lakes, and dead ends. The boundary loops bounding each water area are identified correctly, and the additional grids are created compatibly, aiming at the finite-depth and zero-depth patterns of storage zones. The computation equations of relevant parameters used for 3D stretch from triangles to triangular-prisms are built, and the 1D/2D/3D correspondence on river reaches, junctions, ponds, lakes, dead ends, and control structures is established. Finally, practical examples for discretizing real-world water areas are provided to demonstrate the robustness and effectiveness of our developed mesh generator by using the skewness as the mesh quality metric. [ABSTRACT FROM AUTHOR]

The main pond within the historic Royal Botanic Garden Edinburgh is an important component of urban blue-green infrastructure. This paper reports on flood resilience provided by the pond (simulated using the CityCAT hydrodynamic model), its water residence times (obtained using the Shetran hydrological model), and the ecology and biodiversity (vascular plants, bryophytes, aquatic invertebrates, phyto- and zooplankton, birds) of the pond and the adjacent area. The results show that the pond improves the flood resilience with at least a 27% reduction in the peak discharge during a 1 h, one in 100-year event. The area represents a biodiversity hot spot with a range of native taxa occurring among introduced plant species. The plankton community is dominated by diatoms, reflecting elevated levels of turbulence and a relatively short residence time, with an average value of 10 days. Analysis of macroinvertebrate community indicates a potential for water quality improvement. The results are discussed in relation to multiple societal benefits related to flood resilience, recreation, education, water quality, amenity and biodiversity value. The conclusions may prove particularly valuable for introducing practical measures in the water catchment, preventing waterlogging of the soil and ensuring an uninterrupted supply of public services. This article is part of the theme issue 'Urban flood resilience'. [ABSTRACT FROM AUTHOR]

The paper analyzes an extreme situation of a tailings pond located upstream of the city of Baia Mare and flanked by two localities: Satu Nou de Sus and Tăuții de Sus. The two localities have agricultural and animal husbandry activities, including in the contamination area of the pond, with an increased risk to the health and safety of the population due to its chemical and physical instability. A personal analysis carried out recently has revealed worrying effects on some people and animals in the area. The cause of these effects could be the state of unfinished closure and greening works. Residents directly affected are not warned by the authorities about the risks, and those who requested information before the construction of the houses at the base of the pond began, were assured that the pond is rehabilitated and does not present risks. [ABSTRACT FROM AUTHOR]

As the demand for copper on national and international markets is growing and the opening and exploitation of new deposits is increasingly difficult (both financially and in terms of environmental protection requirements), the recovery of this metal from tailings ponds is of increasing interest. The paper presents the research undertaken in order to recover the copper from the Valea Șesei tailings pond, Roșia Poieni, a pond that stores 100 milions square meters of waste, with an area of approximately 260 ha. Laboratory research conducted for the recovery of copper, the only element that may be of economic interest, focused on the method of concentration by flotation, testing three technological variants, in different working conditions, the results obtained making it possible to advance Another possible method of recovering copper from this industrial waste is by bacterial solubilization, a process that takes place anyway due to the action of heterotrophic bacteria of the genus Thiobacillus, nitrifying bacteria, sulfur-oxidizing bacteria and sulfate-reducing bacteria. [ABSTRACT FROM AUTHOR]

The scope of this study consists of setting up of an integrated cost-effective sampling & laboratory analyses procedure which delineates sampling, sub-sampling and analytical uncertainties in case of fine-grained extractive waste deposits. This procedure is designed to support the decision makers towards fine-grained waste deposits upcycling and land reclamation. This procedure consists of a balanced replicated sampling design (BRSD) coupled with a three split levels ANOVA data processing. The paper provides the readership with the mathematical backgrounds of the three split level ANOVA analysis (3L-ANOVA) and an Excel algorithm for its implementation. Also, the paper presents an example of implementation of the developed methods in the case of a Romanian iron ore tailings (IOT) old pond. The findings of the paper consist of: a) argues, based on OM, SEM-EDS, XRFS and XRD observations, that classical TOS is ineffective for fine-grained waste deposits; b) BRSD in conjunction with 3L-ANOVA analysis is the only approach fit for reliable characterization of the fine-grained stockpiles; c) sampling uncertainty is the critical factor of the uncertainty budget of the analyte concentration; d) Lilliefors approach is adequate for the hypothesis testing where or not the measurand is normal distributed; e) The outcomes of the BRDSD&3L-ANOVA investigations carried on Teliuc tailings, estimated at circa 5.5* 106 m3, consist mainly of mineral quantification at lot level i.e. quartz ∼54% (±7%), hematite ∼15% (±3%), calcite ∼11% (±3%), MgO 3% (±1%), Al2O3 9% (±2%). The concentrations of some CRMs like Ti, V, Ba, Y, W were found at ACE limits and their associated relative expanded uncertainties overpass 50%. Thus, the expanded uncertainties clearly depict the reliability of acquired data for the decision makers regarding waste valorization. f) The IOT into Teliuc can be upcycled as minerals for cement and ceramic industries as well as for geopolymer manufacture. Also, IOT can be downcycles as filler in road construction and mine closure. Finally, the Teliuc yard can be rehabilitated with zero-waste left behind. The data exactness provided by this procedure can be increased to any desirable level through increasing the number of collected items, but the cost of sampling and analyses increases proportionally. In such circumstances, the posted approach can be tailored at the stakeholder request as to safely underpin the decision to turn finegrained by-products into valuable secondary resources, facilitating a greater circularity of the mining industry. • Tailings valorization critically depends on the data reliability regarding pond content. • The sampling, subsampling and analytical uncertainties quantify the data reliability. • Balanced replicated sampling design coupled with three split levels ANOVA is proposed. • Teliuc pond contains quartz (54%), iron oxide (17%), calcite (10%) and others minor ones. • All minerals can be recycled as iron ore, additive in cement industry and geopolymers etc. [ABSTRACT FROM AUTHOR]

The paper demonstrates the capability of using cockle shells as an adsorbent for phosphorus removal from simulated petrochemical wastewater, focusing on the actual condition of the petrochemical facultative pond. In this study, the physicochemical properties of shell powder were determined, such as the functional groups, surface morphology, crystalline structure, and surface area using FTIR, SEM, EDX, XRD, and BET. It was observed that the optimum conditions for effective phosphorus removal are under the presence of rotational speed (125 rpm), higher dosage (7 g/L), and larger surface area (smaller particle size) of the shell powder. Fine powder achieved up to 52.27% of phosphorus removal after 40 min compared to coarse powder which could only give 16.67% removal. Additionally, calcined shell powder demonstrated a higher phosphorus removal rate, i.e., up to 62.37%, compared to raw shell powders. The adsorption isotherm was studied using Langmuir and Freundlich models, but the isothermal data fit better for the Freundlich model (R2 = 0.9836). Overall, this study has successfully generated a greener and low-cost adsorbent. [Display omitted] • The paper discussed the preparation of adsorbent from raw and calcined cockleshell. • The physical and morphological analysis of the adsorbent has been studied. • The removal factors for phosphorous adsorption have been studied. [ABSTRACT FROM AUTHOR]

This paper evaluates two roof pond configurations combined with a water-to-air heat exchanger (WAHE). Test cells of 1.35 m × 1.35 m x 1.35 m with the same thermal properties, except for the roofs, are built in a hot-dry climate with mild winters. They are connected with a WAHE placed inside the roof pond's water by a pipe through which the indoor air is re-circulated. The first roof consists of a 0.35 m deep water pond covered with a floating polystyrene insulation 0.03 m thick, and a spray system located 0.5 m above it that operates at night. The second roof is covered with an aluminum plate separated by a 0.10 m air gap above a 0.25 m deep water pond. We ran multiple series and compared the results to a control cell that had a California energy code compliant insulated roof. Predictive equations are developed to dimension the WAHE system. Results demonstrate that the cells with roof ponds have better cooling performance than the code compliant control cell. The best performance is obtained in the cell with the WAHE operating continuously. In this case, the indoor temperature stayed below 24 °C even with ambient temperatures above 35 °C. • WAHE systems integrated in roof ponds provide an additional cooling opportunity. • Test cells have been monitored for over two years in a hot and dry climate. • The benefits of integrating WAHE in roof ponds are assessed with promising results. • Predictive equations to dimension the WAHE system are developed. [ABSTRACT FROM AUTHOR]

Spain is a country dominated mainly by a Mediterranean climate of, where the annual dry summers alternate with occasional long periods of rainfall drought. This irregularity in the rainfall regime has generated serious socio-economic problems throughout history, due to the weight that the agrarian sector has had, and has, in many regions of the country. This paper presents some ways in which the agrarian sector has adapted to this environmental limitation at different scales (government, region and farm), particularly in the second half of the 20th century thanks to technological advances. Examples of government planning of land conversion into irrigated lands based on the construction of reservoirs or canals, adaptations at the regional scale of agricultural lands, or construction of key infrastructure at the farm level to improve productivity are some of the paradigmatic cases treated here. [ABSTRACT FROM AUTHOR]

Highlights • An analytical stochastic model developed for storm water quality control ponds. • Accuracy of the proposed model was validated comprehensively. • Use of the model for design purposes was illustrated. Abstract Storm water detention ponds are recognized as an effective type of treatment facility for urban storm water management purposes. This paper presents methodologies for the development of an analytical stochastic model describing the hydrologic operation of storm water quality control detention ponds with outflows controlled by orifices. The concept of effective storage capacity is proposed to properly represent a pond's storage in its stochastic water balance equation. The accuracy of the analytical stochastic model (ASM) is verified for many different hypothetical design cases. It is shown that the ASM for detention pond systems can provide accurate results for almost all possible design conditions. Implemented easily into a spreadsheet, the ASM provides an easy-to-use and computationally-efficient tool for analyzing the hydrologic performance of detention pond systems. The ASM can be used separately as a planning or design tool or together with continuous simulation models to help verify simulation results or reduce the number of simulation runs. [ABSTRACT FROM AUTHOR]

Highlights • Simulates the long-term suspended sediment dynamics in a stormwater pond. • Evaluates long-term impact of sedimentation on stormwater pond performance. • Explain the benefits of sediment trapping in the stormwater pond on water quality. • Explores the variation in annual sediment loading with rainfall quantities and pattern. Abstract The influence of long-term suspended sediment dynamics on stormwater pond performance should not be ignored, but is often neglected in pond design and performance evaluation. This paper provides systematic simulated quantification of long-term suspended sedimentological effects on stormwater pond performance. Integrated hydrological and two-dimensional hydro-morphodynamic modelling and simulations were carried over a 32-year period (1984–2015) covering 3896 rainfall events with a wide range of rainfall volumes, durations and intensities. Three event-based hypothetical rainfall scenarios: non-flood condition (5-year), sewer design condition (30-year), and river flood condition (100-year) rainfall events with 1-h duration, were also simulated for comparison between the traditional event-based approach and the novel approach presented in this study. Simulation results show that the flood peak attenuation and delay are more pronounced for small (<5-year) and medium (<30-year) flood events. The long-term continuous simulation results indicate that the pond provides positive annual trap efficiencies varying from 2% to 69% for 31 of 32 years, providing long-term water quality benefits downstream. However, an extreme rainfall event in year 2012 flush out the accumulated sedimentation as a shock load to the downstream river, leading to a negative trap efficiency of −11%. The spatially averaged sediment deposition rate, as predicted by the model, varies with a mean (SD) of 2 (1.34) cm/year over the study period, which resulted in a 24% loss in the pond's volume over 32 years. The impact of the loss in storage on pond flood attenuation capacity are explored at regular time intervals over the study period. The results indicate that reduction in the pond's flood attenuation capacity is relatively more pronounced for medium (30-year) and extreme (100-year) flood events than the frequent small flood (5-year) events. The variation in annual sediment loading with rainfall quantities and patterns are also explored. [ABSTRACT FROM AUTHOR]

Striped mullet, Mugil cephalus, is an abundant inshore fish in Florida waters and has served as the foundation for foodways along the Gulf Coast for thousands of years. Distributed globally in temperate to tropical waters, M. cephalus and other mullet species are cultivated in fish ponds in a wide range of locales. In Florida, however, commercial and subsistence fishing folk use various nets to harvest wild striped mullet from open in-shore ecosystems, supplying food for the marketplace and households. As the low-cost, "bread and butter" species of Florida's commercial fishing industry, mullet and the inshore ecosystems it inhabits function as a source of collective sustenance for everyday people from a variety of racial, ethnic, and class backgrounds. In the process of feeding people over the centuries, mullet generated collective allegiance to inshore waterways dedicated to provision rather than proceeds. In this paper, I argue that mullet-dependent people in Florida defended commitments to a relationship between themselves, the inshore marine waters, and everyday consumers as an alternative to the conversion of the state's seascapes into capitalist spaces dedicated to leisure and tourism-oriented commerce. Lisa cabezuda, Mugil cephalus, es un pez costero abundante en las aguas de Florida y ha servido como la base para los alimentos a lo largo de la costa del Golfo durante miles de años. Distribuidas globalmente en aguas templadas a tropicales, M. cephalus y otras especies de lisa cabezuda se cultivan en estanques de peces en una amplia gama de lugares. No obstante, en Florida los pescadores comerciales y de subsistencia utilizan varias redes para cosechar lisa cabezuda de ecosistemas costeros abiertos, que suministran alimentos para el mercado y los hogares. Como la especie de "pan y mantequilla" de bajo costo de la industria de la pesca comercial de Florida, las lisa cabezuda y los ecosistemas costeros que habitan funcionan como una fuente de sustento colectivo para las personas cotidianas con una variedad de antecedentes raciales, étnicos y de clase social. A lo largo de los siglos, en el proceso de alimentar a las personas, la lisa cabezuda generó lealtad colectiva a las vías fluviales costeras dedicadas a la provisión en vez de los ingresos. En este artículo, sostengo que las personas dependientes de lisa cabezuda en la Florida defendieron los compromisos de una relación entre ellos, las aguas marinas costeras y los consumidores cotidianos como una alternativa a la conversión de los paisajes marinos del estado en espacios capitalistas dedicados al ocio y al comercio orientado al turismo. [ABSTRACT FROM AUTHOR]

Many frog species reproduce in temporary ponds maintained exclusively by rainfall, thereby being exposed to drought and possibly mortality of eggs and tadpoles. Some tadpoles, however, can survive for up to 5 days out of water but few data are available regarding the effects of dehydration on their development. The aim of this study was to evaluate whether hydric stress affects the locomotor capacity and the morphology in tadpoles of two leptodactylid frog species showing different reproductive modes (Leptodactylus fuscus and Physalaemus nattereri), examining specifically: (a) difference in survival rate and body mass between tadpoles at different hydration levels, (b) the hydric stress effect on locomotor performance, (c) difference in external morphology, and (d) visceral volume among tadpoles suffering hydric stress. Tadpoles for both species were divided into two groups, one staying in 100 ml of water and the other maintained on absorbent paper with 4 ml of water for 12, 24, and 72 hr (n = 20 each). Significant differences in weight loss were found between the groups of both species, the treatment losing more weight in all stress levels. Almost half of P. nattereri tadpoles died within 36 hr of hydric stress. We found no difference in locomotor performance between groups of L. fuscus tadpoles, but significant differences in locomotor performance, tail morphometry, and visceral volume between groups of P. nattereri tadpoles. Our results suggest that hydric stress has a significant effect on locomotion and morphology of P. nattereri tadpoles but not in L. fuscus. HIGHLIGHTS: Many anuran species reproduce in pools that can dry out completely.We evaluate the effect of dehydration in tadpoles from temporary ponds.Survival capacity and locomotion performance were affected for one of the species, but not in another. Effect of dehydration on locomotor performance and survival capacity in tadpoles of two species from temporary ponds. [ABSTRACT FROM AUTHOR]

Highlights • A new set of machine learning approaches to analyse senor data from prawn ponds. • Identification of relationships between water quality variables and yield. • A novel water quality variable data set from a prawn farm in South East Asia. Abstract A number of variables can affect the harvest yield in prawn ponds including dissolved oxygen, ammonia, pH, nitrite, and so on. A set of industry standards are there to maintain these variables within specific ranges for maintaining ideal growing environments for the prawns. However recent harvest results in a prominent prawn farm in South East Asia have shown different performance across ponds even after maintaining these variables within the industry standard ranges. An experiment was conducted recently to collect data on different influence variables (mentioned above) by measuring them at different times over the whole prawn growing season. We have conducted a set of analytical experiments on this data set using machine learning methods to answer three questions: (1) What level of predictive power do the influence variables have i.e. how well they can differentiate between good and bad performing ponds, (2) What is the relative importance of influence variables in predicting pond performance, and (3) How the perceived variables influence the harvest metrics. The paper presents a set of machine learning based analytical approaches undertaken to answer these questions. [ABSTRACT FROM AUTHOR]

In order to investigate the influence of season changes of environmental factorr in closed shrimp ponds on the community structure of planktonic microalgae, this paper conducted isolated tests to the temperature, pH, total nitrogen (TN), total phosphorus (TP) and chlorophyll a in the shrimp culture ponds, analyzed the planktonic microalgae community structure and changes of dominant species in water over the same period, with the aim to explain the responses of microalgae community to changes of environmental factors in the pond without foreign water sources. The results showed that pond water temperature and TP content gradually increased from April to the end of September and then declined in October; water pH first decreased and then increased; TN and chlorophyll a first increased and then decreased. The dominant species in the pond were Cyclotella sp., Navicula sp., Oocystis and S. quadricauda in the early stage (Apirl-May), Chlamydomonas sp., Chlorella sp., S. quadgcauda, Golenkinia radiata and Pseudanabeanain in medium stage (June - July), Microcystis, Pseudanabeana, Chlorella sp. And S. quadgcaudain in the mid-late stage ( August - September), Microcystis, Pseudanabeana, Oscillatoria sp. and Chlorella sp. in the late stage ( October - December), and Chlorella sp., Golenkinia radiate, S. quadrcauda in the last stage. Diatoms and green algae were the dominant species in the early stage when the water had low temperature, low N and P nutrition but high N/P and a certain salinity. With the increase of temperature, water desalination and accumulation of N and P nutrition, algae became the dominant species. Cyanobacteria became the strong dominant stages in the mid-late stage when the water had high temperature in the state of eutrophication, and there were also some green algae which were fond of high temperature and had resistant to pollution. In the late stage, cyanobacteria were the absolute dominant stage, but with the decrease of water temperature in the last stage, green algae became the dominant species, and planktonic microalgae biomass in the pool decreased. [ABSTRACT FROM AUTHOR]

Aquaculture involves cultivating various marine and freshwater aquatic creatures within regulated environments. Monitoring the aquatic environmental conditions in real-time is crucial for successful fish farming. The Internet of Things (IoT) offers significant potential for real-time monitoring, and this paper introduces an IoT framework designed for efficient monitoring and effective control of various water-related aquatic environmental parameters. The proposed system is implemented as an embedded system utilizing sensors and an Arduino microcontroller. In cultivating pond water, diverse sensors such as pH, temperature, and turbidity sensors are deployed, with each sensor connected to an Arduino Uno-based microcontroller board. These sensors collect data from the water, which is then stored as a CSV file in an IoT cloud platform called ThingSpeak through the Arduino microcontroller. To gather data for analysis, we conducted measurements across five ponds, varying in size and environmental conditions. After getting the real-time data, we compared our experimental results with the standard reference values. As a result, we could take the decision of whether a pond is suitable for cultivating fish or not. After that, we labeled the data with 11 fish categories: Katla, sing, prawn, shrimp, rui, tilapia, pangas, karpio, magur, silver carp, and koi. The data was analyzed using 10 machine learning (ML) algorithms, including J48, Random Forest, K Nearest Neighbors (K-NN), K*, Logistic Model Tree (LMT), Reduced Error Pruning Tree (REPTree), Jumping Rule Inference with Pruned Search (JRIP), Partial Decision Trees (PART), Decision Table, and Logit boost. After experimental analyses, it was discovered that only three of the five ponds were ideal for fish farming, and those three ponds only met the required standards for pH, Temperature, Turbidity, and Conductivity. Among the state-of-art machine learning algorithms, Random Forest achieved the highest score of performance metrics as accuracy 94.42%, kappa statistics 93.5%, and Avg. TP Rate 94.4%. In addition, we calculated the Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), and Dissolved Oxygen (DO) for one scenario. This study includes prototype hardware details of the proposed IoT system. [ABSTRACT FROM AUTHOR]

In eutrophic freshwater ecosystems, submerged macrophyte communities are replaced by phytoplankton or free-floating plants. In isolated wetlands, vegetation shift occurs over short time scales and leads to water deoxygenation and chemically reduced sediments, conditions that favor the generation, accumulation and degassing of greenhouse gases (GHGs, i.e. CH 4 , CO 2 and N 2 O) to the atmosphere. However, the relationship between primary producer's growth forms, hydrological connectivity and GHGs concentration is poorly studied in the literature. A set of 18 freshwater wetlands including isolated and river-connected oxbow lakes, marshes and ponds with different vegetation growth forms was therefore monitored monthly on the annual scale. Potential GHGs diffusive fluxes towards the atmosphere were calculated and compared with direct measurements reported in peer-reviewed papers within a meta-analysis. Our results demonstrate a strong link between the colonization of free-floating plants and the onset of hypoxic conditions and accumulation of dissolved methane. Methane and carbon dioxide concentration peaked in late summer, when floating-leaved and free-floating vegetation covered 100% of the water surface. Carbon dioxide accumulation was particularly evident at hydrological connected wetlands, where nitrate pollution was likely responsible for the concomitant increment of dissolved nitrous oxide. As an increasing number of studies focuses on unravelling environmental drivers of GHGs emission from small lakes and ponds, we encourage to systematically consider the vegetation growth forms and the hydrological connectivity as major drivers of GHGs accumulation and evasion rates. • Eutrophic small waterbodies are supersaturated in greenhouse gases. • Free-floating plants dominance favors hypoxic conditions and accumulation of CH 4 and CO 2. • In hydrologically connected wetlands nitrate loads favor N 2 O supersaturation. • Vegetation shift and nitrate input lead to increased GHG emissions. [ABSTRACT FROM AUTHOR]

Catfish is a fish that is increasingly in need in Indonesia and is one of the mainstays in increasing aquaculture productivity. This study aims to analyze the production performance and financial feasibility of catfish culture using pond media and analyze the marketing performance of catfish. This study uses a survey method. The research location was determined purposively in Banjar Regency; the research respondents were catfish cultivators in ponds, collectors, retailers, and catfish consumers. The data collected were analyzed descriptively; financial analysis, marketing margin analysis, and farmer share analysis were also used. The results showed that catfish cultivators had implemented good and correct technical cultivation activities, farming in ponds was financially feasible, and the catfish marketing system was running efficiently. [ABSTRACT FROM AUTHOR]

The experiment was established at an earthen aquaculture private farm in Kafrelshikh Government, Egypt. During 2021. To study the effect of operational variables at tube diffusion aeration system on turbidity values corresponding to Secchi disk clarity. Experimental variables under study were five air flow rates (0.1, 0.18, 0.23, 0.28 and 0.33 m³.h-1), three tube wall thickness (4, 6 and 7 mm), three tube depth from water surface (0.3, 0.50 and 0.70 m) and two design shapes for aeration system (circular and Longitudinal). Aeration system consist of circular tube holder, an electric single-phase compressor, three models of rubber diffusion tubes (D25-4, D25-6 and D25-7), portable galvanic dissolved oxygen meter, Secchi disk, digital LCD anemometer and thermometer and digital vernier. The results showed that, the lowest value for Secchi disk clarity were 7 cm obtained at operational conditions of 0.33 m³.h-1 air flow rate, 0.70 m depth from water surface, 4 mm thickness of tube wall and circular shape design. While, the highest value for Secchi disk clarity were 41 cm obtained at operational conditions of 0.10 m³.h-1 air flow rate, 0.30 m depth from water surface, 7 mm thickness of tube wall and Longitudinal shape design. The permissible variables limits were (0.1, 0.18 and 0.23 m³.h-1) for air flow rate, (4, 6 and 7 mm) for tube wall thickness, (0.3, 0.50 and 0.70 m) for tube depth from water surface and both of (circular and Longitudinal) design shapes. [ABSTRACT FROM AUTHOR]

The risk associated with urban flooding is expected to increase significantly in the future as a result of urbanization and climate change. It is therefore necessary to develop new strategies and tools for managing urban floods. With the increase of impervious surfaces in urban areas, due to rainfall rainwater on the surface tends to accumulate in ponds. The delimitation of these areas is important because they outline possible areas vulnerable to flooding. In this paper we have proposed the automatic identification of these ponds by developing an algorithm using the Model Builder tool of ArcGIS program. The model was applied to LiDAR data for the city of Wrocław in Poland, a city with a high risk of urban flooding. The Model Builder tool successfully delimits the ponds at the ground surface based on a Digital Elevation Model (DEM), without being necessary a manual intervention, thus saving time and energy for the users. [ABSTRACT FROM AUTHOR]