Water Quality Conditions Research Articles

Artificial Intelligence for Application in Water Engineering: The Use of ANN to Determine Water Quality Index in Rivers

To improve water quality, total daily loads must be established, and this requires determining the quality of the water in rivers, storage tanks, ponds, and coastal areas. Current methods to evaluate water quality involve the collection of water samples for subsequent laboratory analysis. Although these technologies offer precise measurements for a specific location and time, they are expensive, time-consuming, and do not provide the continuous, temporal, or spatial conditions of water quality that are required for managing, assessing, and monitoring water quality. In order to calculate the water quality, the water quality index is modeled using artificial neural network models that incorporate feedforward neural network backpropagation neural networks and radial neural networks. The water quality index of Malaysia’s Klang River was determined by training the artificial network using six major sub-quality parameters. Compared to the current method, the artificial neural network simplifies and expedites the computation of the water quality index. The artificial neural network method could provide a significant saving in terms of money and time while offering a robust assessment of water quality. The proposed method could also be used as an early warning system for pollution of water bodies. The best artificial neural network was the feedforward neural network with one hidden layer containing 5 neurons. Furthermore, conventional approaches for calculating the water quality index rely on empirical equations, often introducing a high degree of approximation and uncertainty into the results. Moreover, these equations cannot be applied when some parameters are not measured. In contrast, the artificial neural network methods and technique offer an efficient and straightforward process for estimating and creating prediction models for water quality index. Doi: 10.28991/CEJ-2024-010-07-012 Full Text: PDF

The Dynamics and Water Quality Status of a Tropical Coastal Lake in Anak Laut Lake, Singkil Indonesia

The Dynamics and Water Quality Status of a Tropical Coastal Lake in Anak Laut Lake, Singkil Indonesia

Comparative study of polystyrene microplastic transport behavior in three different filter media: Quartz sand, zeolite, and anthracite

Microplastics (MPs) are emerging contaminants that are attracting increasing interest from researchers, and the safety of drinking water is greatly affected by their transportation during filtration. Polystyrene (PS) was selected as a representative MPs, and three filter media (quartz sand, zeolite, and anthracite) commonly found in water plants were used. The retention patterns of PS-MPs by various filter media under various background water quality conditions were methodically investigated with the aid of DLVO theory and colloidal filtration theory. The results show that the different structures and elemental compositions of the three filter media cause them to exhibit different surface roughnesses and surface potentials. A greater surface roughness of the filter media can provide more deposition sites for PS-MPs, and the greater surface roughness of zeolite and anthracite significantly enhances their ability to inhibit the migration of PS-MPs compared with that of quartz sand. However, surface roughness is not the only factor affecting the migration of MPs. The lower absolute value of the surface potential of anthracite causes the DLVO energy between it and PS-MPs to be significantly lower than that between zeolite and PS-MPs, which results in stronger retention of PS-MPs by anthracite, which has a lower surface roughness, than zeolite, which has a higher surface roughness. The transport of PS-MPs in the medium is affected by the combination of the surface roughness of the filter media and the DLVO energy. Under the same operating conditions, the retention efficiencies of the three filter materials for PS-MPs followed the order of quartz sand < zeolite < anthracite. Additionally, the conditions of the solution markedly influenced the transport ability of PS-MPs within the simulated filter column. The transport PS-MPs in the simulated filter column decreased with increasing solution ionic strength and cation valence. Naturally, dissolved organic matter promoted the transfer of PS-MPs in the filter layer, and humic acid had a much stronger facilitating impact than fulvic acid. The study findings might offer helpful insight for improving the ability of filter units ability to retain MPs.

Abundance and Distribution of Benthic Macro-Invertebrates of Luhu Dam, Michika, Adamawa State, Nigeria

The study uses benthic macroinvertebrates as indicators to assess water quality in the Luhu Mini Dam, Michika, Adamawa State. The study involves the collection of benthic macroinvertebrate samples over six months, utilizing the Van Veen grab method for sampling and preservation in formalin. Upon transportation to the laboratory, the samples were identified and subjected to statistical analysis, including the Shannon and Weiner Index, Margalef’s Index, Simpson’s diversity Index, and Pielou’s Evenness. The study aims to provide fundamental information on the health of the Luhu Mini Dam and to understand the water quality and pollution status, thereby informing necessary management measures. The distribution and diversity of species across three different stations. A total of 462 individuals representing 20 taxa from 3 phyla were collected. Station 1 yielded 16 taxa and 162 individuals, station 2 had 17 taxa and 201 individuals, and station 3 had 17 taxa and 99 individuals. The diversity indices revealed variation in the number of species across stations, with stations 3 and 2 having the highest number of species, while station 1 had the lowest. The general diversity (H') was highest at station 3, followed by stations 1 and 2, whereas station 3 also exhibited the highest Evenness index (E). Moreover, the taxa richness index, as calculated by Margalef's Index (d), peaked at station 3. Simpson's dominance index showed that Station 2 exhibited the highest dominance, followed by Station 1 and Station 3. These findings provide valuable insights into the distribution and diversity of species across different biotopes.

Effect of Adding Calcium Dolomite (CaMg(CO3)) and Tohor (CaO) in Cultivation Media to Increase Moulting of Litopenaeus vannamei

Vaname shrimp (Litopenaeus vannamei) is a fishery commodity that is the largest contributor to exports compared to other commodities. The success of shrimp survival and growth cannot be separated from the molting process, which requires calcium. The calcium that absorbed from the cultivation media can play a greater role in the process of exoskeleton formation. Dolomite lime (CaMg(CO3)) and tohor (CaO) can be sources of calcium that can be added to cultivation media. The research method used in this study was a completely randomized design (CRD) consisting of 5 different treatments (A: without additional lime, B: 0.8 gr dolomite, C: 0.8 gr tohor, D: 0.3 gr dolomite + 0.5 gr of tohor, E: 0.5 gr of dolomite + 0.3 gr of tohor) with 3 repetitions. The results showed that the addition of lime at different doses provided a molting frequency ranging from 2.07 – 3.23 times during the 60 days rearing period, where treatment E was the optimum treatment. The absolute weight growth obtained ranged from 2.52 gr – 5.03 gr, with an absolute length of 5.25 cm – 9.11 cm. The highest survival rate during maintenance in treatment E reached 72%. The water quality conditions measured during the activity were alkalinity 135 – 146 ppm, Ca hardness 132.74 – 172.39 ppm, temperature 29.9 – 30.3°C, DO 6.3 – 6.5 mg/l, pH 7 .9 – 8.3 and salinity 32 -34 ppt.

Assessments of Water Quality and Plankton Diversity in the Baur Reservoir, Uttarakhand, India

The current investigation was conducted between January and December of 2022. During the study period water quality was studied in Baur reservoirs two spot, one spot is a barrage area, and the second one is four kilometers away from the first one. The present study is done in Baur Reservoir, which is switched to Gularbhoj in Udham Singh district. Reservoir water is used for irrigation and domestic purposes. Many villages are located near the reservoir, so due to human interaction, water quality may be affected. For this reason, the present study finds parameters of water so we can identify the present water quality status, as we know many similar work done all over India but in this study we find present condition which may be change from past condition and as we know climatic condition are change now days so we can find rainfall in every month and other parameters of reservoir. Various quality parameters are measured, including PH, water temperature, DO, CO2, total alkalinity, total solid, turbidity, total suspended solids and total dissolved solids. All the parameters are within the permissible limit and suitable for domestic use, pisciculture, and agriculture. Water quality parameters have been observed to vary and, with the exception of temperature, all show a positive correlation with the production of phytoplankton and zooplankton in the chosen reservoirs. These parameters include temperature, pH, dissolved oxygen, carbon dioxide, and total dissolved solids. The temperature varies from 240c+ 60c, the pH varies from 7.0 + 2, the dissolved oxygen range varies from 7+ 3, range of carbon dioxide varies from 6+ 5, the humidity range is 50+25, and rainfall throughout varying the all study period. All the physico-chemical parameters are the relation to plankton diversity. In this study, we also find plankton diversity status in Baur reservoir. Plankton diversity can also help to find out the water quality; healthy plankton growth may relate to water quality as well as fish diversity. In the following study, we find the groups Copepoda, Clyadocera, and Rotifera, each containing 6, 6 and 2 respectively. The groups Bacillariophyceae and Chlorophycae each contain 29 and 23, respectively, phytoplankton taxa. The study looked at the association between group variation in physico-chemical parameters for the Cyanophyceae, Dinophyceae, and Euglenophyceae. With the help of this study, we can find the pollutant status and water quality level in the Baur reservoir. All the water quality parameters are under safety level and are good for irrigation purposes and for domestic use. They can filtrate, and may relevant department may take action for tourist activity that causes pollution in reservoir water.

Water-quality assessment and spatial distribution of water-quality parameters of Dodoma Urban, Tanzania

The study was conducted in 2022 in shallow wells and deep boreholes owned by residents, to investigate the water quality status in the emerging developing area of Dodoma Urban municipality in central Tanzania. Eighteen boreholes and five shallow wells were assessed using the water quality index (WQI), the inverse distance weighting (IDW) method under the ArcGIS environment, and the Euclidean similarity index. The WQI classified the water samples into a good category class with a covered area of 42.5% and an excellent category class with a covered area of 57.5%, indicating that most of the deep boreholes and shallow wells were suitable for residential purposes. The IDW revealed the spatial distribution of the physico-chemical parameters and WQI, indicating that water quality improved from west to east within the study area. Yet, the Euclidean similarity index was dominated by nitrates, pH and heavy metals, with the highest correlation coefficients. Despite the WQI being above the average class, water treatment technologies should be practiced to lower those values of physico-chemical parameters existing above the threshold limits.

Analisis Status Kualitas Air di Sungai Porong yang Tercemar oleh Deterjen terhadap Respon Hematologi Ikan Java Barb (Barbonymus gonionotus)

The Porong River is one of the rivers that faces high anthropogenic impacts, such as surfactant waste from detergents. The hematology of Javanese carp (Barbonymus gonionotus) serves as a sentinel organism that can be used as a biomarker for the waters of the Porong River. The aim of this study is to analyze the water quality status of the Porong River polluted with surfactants using the STORET method, as well as its impact on the hematology of Javanese carp using regression and correlation analysis. The research employed a descriptive survey method. The results of the study indicated that the Porong River was categorized as moderately polluted. The average highest surfactant concentration reached 7.2 mg/L, leading to an increase in TSS to 107.95 mg/L and a decrease in DO to 1.80 mg/L. Surfactants exhibited a negative correlation with erythrocytes (91.2%), hematocrit (47.7%), and hemoglobin (60.6%), indicating that the higher the surfactant concentration, the lower the number of erythrocytes, hematocrit levels, and hemoglobin levels in Javanese carp. Conversely, there was a positive correlation between surfactants and leukocytes (56.7%) and blood glucose (66.7%), suggesting that the higher the surfactant concentration, the higher the number of leukocytes and blood glucose levels in Javanese carp.

Ecological restoration for eutrophication mitigation in urban interconnected water bodies: Evaluation, variability and strategy

Many urban water bodies grapple with low flow flux and weak hydrodynamics. To address these issues, projects have been implemented to form integrated urban water bodies via interconnecting artificial lake or ponds with rivers, but causing pollution accumulation downstream and eutrophication. Despite it is crucial to assess eutrophication, research on this topic in urban interconnected water bodies is limited, particularly regarding variability and feasible strategies for remediation. This study focused on the Loucun river in Shenzhen, comprising an pond, river and artificial lake, evaluating water quality changes pre-(post-)ecological remediation and establishing a new method for evaluating the water quality index (WQI). The underwater forest project, involving basement improvement, vegetation restoration, and aquatic augmentation, in the artificial lake significantly reduced total nitrogen (by 43.58%), total phosphorus (by 79.17%) and algae density (by 36.90%) compared to pre-remediation, effectively controlling algal bloom. Rainfall, acting as a variable factor, exacerbated downstream nutrient accumulation, increasing total phosphorus by 4.56 times and ammonia nitrogen by 1.30 times compared to the dry season, and leading to algal blooms in the non-restoration pond. The improved WQI method effectively assesses water quality status. The interconnected water body exhibits obvious nutrient accumulation in downstream regions. A combined strategy that reducing nutrient and augmenting flux was verified to alleviate accumulation of nutrients downstream. This study provides valuable insights into pollution management strategies for interconnected pond-river-lake water bodies, offering significant reference for nutrient mitigation in such urban water bodies.

Effects of water replenishment on lake water quality and trophic status: An 11-year study in cold and arid regions

Water replenishment is an important measure for maintaining and improving the aquatic environmental quality of lakes. The problems of water quality deterioration and water shortage can be alleviated by introducing water of higher quality. However, the mechanism of water replenishment in the improvement of the water quality and trophic status of lakes remains unclear. This study investigated water replenishment in Wuliangsuhai Lake (WLSHL) from 2011 to 2021 by collecting seasonal water samples and conducting laboratory analyses. Water replenishment was found to be capable of significantly improving lake water quality and alleviating eutrophication. It is worth noting that single long-term water replenishment measures have limitations in improving the water quality and trophic status. The whole process was divided into three stages according to the water quality and trophic status, namely the buffer period, decline period, and stable period. During the buffer period, the water quality and trophic status showed only slight improvement because of the small amount of water replenishment and the low proportion of higher-quality water from the Yellow River. In the decline period, with increasing water replenishment, the proportion of higher-quality water from the Yellow River gradually increased, leading to the most significant and stable degree of improvement. In the stable period, increases in the amount of water replenishment had little effect on improving the water quality and trophic status, which is attributable to the balance between internal pollutants (lake water–sediment), and the balance between internal-external pollutants (lake water–irrigation return flow + Yellow River water). On the premise of stable water quality, with eutrophication control as the management goal, the optimal water replenishment would be approximately 10.58 ×108 m3. Further necessary measures for solving aquatic environmental problems include the combination of sediment dredging, optimization of the water replenishment route, and implementation of quality management in water replenishment.

Influence of biodegradable plastics on the generation of disinfection byproducts in the chlorination process

Biodegradable plastics (BPs) have seen a continuous increase in annual production and application due to their environmentally sustainable characteristics. However, research on the formation of disinfection byproducts (DBPs) from biodegradable microplastics (BMPs) during chlorination is limited, and the effects of aqueous solution chemistry on this process have yet to be explored. Therefore, two biodegradable microplastics, polylactic acid (PLA) and polybutylene adipate terephthalate (PBAT), were investigated in this study to examine the changes in their physicochemical properties before and after chlorination, and the formation of DBPs under different environmental conditions. The results showed that PLA was more chlorine-responsive, and generated more DBPs. The pH converted some of the intermediates into more stable DBPs by affecting the concentration of HClO and base-catalyzed reactions, whereas ionic strength slightly reduced DBP concentration by ion adsorption and promoting the aggregation of BMPs. Finally, since PLA has a slightly greater volume of mesopores and micropores compared to PBAT, it may more effectively adsorb DBP precursors beyond natural organic matter (NOM), such as some anthropogenic pollutants, thus potentially decreasing the formation of chlorinated DBPs in surface water. This research explored the potentiality for DBP formation by BMPs under different water quality conditions during the disinfection process, which is useful for assessing the environmental hazards of BMPs.

A four-season exploration of surface water quality and trophic status in the highly dynamic waters of Karun-4 Dam Lake, SW Iran

This study explores seasonal fluctuations in water quality and phytoplankton communities within Karun-4 Dam Lake, the largest double-arch dam in the Middle East situated in Iran. Employing a systematic approach, 26 sampling stations were strategically selected to collect surface water samples at a depth of 50 cm during the midpoints of each season throughout 2019. Significant seasonal variations in water quality parameters and phytoplankton composition were observed. Predominant species included Chrysophyceae (38%) and Bacillariophyceae (32%), indicative of nutrient-rich conditions, particularly during spring and summer, as evidenced by the eutrophic state (Carlson Trophic State Index: 59.43 and 53.96, respectively). Summer exhibited the highest diversity (Shannon–Wiener Index = 2.27) and lowest evenness (Pielou’s Evenness Index = 0.21). PCA and CCA analyses revealed season-specific preferences for nutrients and ions among phytoplankton species. Water temperature emerged as a crucial factor in spring and summer, while environments with elevated bicarbonate and alkalinity levels were less favorable during winter and fall. This study provides essential insights into Karun-4 Lake's dynamic ecological conditions, underscoring the necessity for ongoing monitoring to discern long-term trends and anthropogenic impacts for effective ecosystem management.

Assembly mechanism and stability of zooplankton communities affected by China's south-to-north water diversion project

Water diversion can effectively alleviate water resource shortages and improve water environmental conditions, while also causing unknown ecological consequences, in particular, the assembly mechanism of zooplankton communities in the affected areas will become more complex after long-term water transfer. Taking Nansi Lake, the second largest impounded lake along the eastern route of China's South to North Water Diversion Project (SNWDP), as an example, the composition and diversity of zooplankton communities in the lake area and estuaries during the water diversion period (WDP) and non-water diversion period (NWDP) were studied. The potential assembly process of zooplankton communities was further explored, and the stability of communities in different regions during different periods was compared. The related results indicated that the changes in water quality conditions induced by water diversion had a relatively weak impact on the zooplankton communities. In the assembly mechanism of zooplankton communities, stochastic process played a more important role during both WDP or NWDP, and the proportion of deterministic process was relatively higher during NWDP, which may be related to the greater role of total nitrogen (TN) in the assembly of the zooplankton communities. The network analysis and cohesion calculation results showed that the stability of the zooplankton communities in the lake area sites was higher than that in the estuary sites, and the stability during NWDP was higher than that during WDP. In sum, the stability of zooplankton communities displayed a degree of change affected by water diversion activities, but the community assembly was not significantly influenced by the water quality fluctuations after about relatively long-term water diversion. This study provides an in-depth understanding of the ecological effects of water diversion on the biological communities in the affected lake, which is beneficial to the management and regulation of long-term water diversion projects.

Coastal CUBEnet: an integrated observation and modeling system for sustainable Northern Gulf of Mexico coastal areas

The University of Southern Mississippi has developed the coastal CUBEnet environment. Coastal CUBEnet is a high-resolution, coastal ocean sensor, modeling, and data sharing web-based network that provides the environmental intelligence needed to support the complex modeling of the interlinked processes in the northern Gulf of Mexico. With near-real time data delivery via a common infrastructure, CUBEnet uses state of the art sensors to provide a set of networked measurements systems, visualization tools, and model developments to gain an understanding of the Gulf of Mexico’s marine environments. CUBEnet is also a mechanism for improved human engagement with Gulf of Mexico resources and provides stake holders with the data needed to make informed coastal, environmental, and economic decisions. The Coastal CUBEnet’s data environment utilizes both stationary and uncrewed mobile systems and high-resolution distributed sensors to create a networked platform across the northern coastal Gulf of Mexico. CUBEnet’s modeling environment has developed an implementation of The Coupled Ocean Atmosphere Wave Sediment Transport (COAWST) Model for the Mississippi Bight region that has been applied to investigate shore to shelf advective exchange processes, and their influence on coastal water quality conditions that support the region’s prolific marine ecosystem. CUBEnet’s modeling environment provides prototype modeling applications that are supported by real-time observations of key coastal environmental variables. CUBEnet’s Web accessible visualization tools provide parameter fields and vertical profiles from hydrodynamic models and field observations. Nowcasts and forecast results are available for the Eastern LA coastline, MS coastline, Mobile Bay, and the West coast of Florida.

A national-scale assessment on the spatial and temporal variations in water color for urban lakes in China

Monitoring the variations of lake water quality is essential for urban water security and sustainable eco-environment health. However, it is challenging to investigate the water quality of urban lakes at large scales due to the need for large-amount in situ data with diverse optical properties for developing the remote sensing inversion algorithms. Forel-Ule Index (FUI), a proxy of quantifying water color, whose calculation does not require in situ data of specific properties, can comprehensively reflect water quality conditions. However, the spatial and temporal distribution of water color in Chinese urban lakes is still poorly understood. To fill this research gap, this study investigated the spatial distribution of water color in 523 urban lakes (area > 0.5 km2) in China using the FUI derived from the high-quality Multi-Spectral Instrument (MSI) data onboard Sentinel-2 during the ice-free period (April–October) from 2019 to 2022. The monthly and seasonal variation patterns of water color in urban lakes were also analyzed. Our results show that green domain is the most common color of urban lakes, with about 86 % of urban lakes in China being green, and non-green lakes accounting for only 14 % of the total number of lakes. The monthly variation of FUI in urban lakes across the country and multiple geographic regions is basically the same. The monthly average FUI first increases, then decreases, and then rebounds. We also found that the seasonal variation of water color in most urban lakes in southern and northern China is opposite. This study helps to comprehensively understand the spatial and temporal variation of water color and quality of urban lakes in China, providing key basic information for the protection and governance of urban lakes.

A novel method for assessing water quality status using MODIS images: A case study of large lakes and reservoirs in China

The changing climate and economic development have exerted significant pressure on the water quality of global lakes and reservoirs (hereinafter referred to as lakes). Existing sporadic in-situ monitoring limits a comprehensive understanding of water quality changes at large spatiotemporal scales. Although remote sensing techniques offer efficient water quality observations, they have primarily focused on monitoring single optical active substances, making it difficult to assess water quality changes caused by chemical indicators such as total phosphorus and total nitrogen. However, changes in chemical indicators within a certain range can cause responses to physical indicators, which are comprehensively reflected in the water-leaving reflectance. Based on this physical mechanism, this study obtained the water quality status categories (from excellent to severe pollution) by calculating the water quality index (WQI) and developed a new remote sensing assessment model of water quality status using moderate resolution imaging spectroradiometer (MODIS) imagery. This model, combining fractional-order derivatives and various-dimensional spectral indices, significantly enhanced the sensitivity of spectral reflectance to water quality states, achieving a maximum correlation of 0.72. To address the applicability of the model at large spatiotemporal scales, this study proposed a classification modeling scheme based on the optimal optical water categories, resulting in a 20.69%–34.48% improvement in model accuracy after classification. Additionally, this study proposed an improved ensemble learning model combining the concepts of Stacking and Bagging, achieving an average accuracy of 82% and enhancing accuracy by 5%–15% compared to the original single model. Subsequently, the model was used for the first time to assess the water quality status of 180 large lakes in China from 2000 to 2022. The results revealed that 76.11% of the lakes exhibited excellent and good water quality, with a spatial distribution pattern showing a “better in the west, worse in the east” pattern. Over the 23-year period, 28.33% and 58.89% of the lakes showed improvement and stability trends in water quality status, with stability and improvement predominating in the western and eastern regions, respectively. The research results provide technical support for the rapid assessment of water quality status and sustainable resource management, highlighting the potential of remote sensing technology in water quality monitoring.

Spatiotemporal characteristics and potential pollution factors of water quality in the eastern route of the South-to-North Water Diversion Project in China

The eastern route of the South-to-North Water Diversion Project (SNWDP-ER) in China, an open-channel cross-basin project, is exposed to multiple potential pollution sources and has changing hydrodynamic conditions between diversion and non-diversion periods. After a decade of pollution control efforts, it is imperative to perceive the water quality conditions and identify potential pollution factors for further maintenance. Combining the water quality identification index (WQII) and multivariate statistical techniques (MSTs), this study conducted an exploratory analysis in SNWDP-ER, based on the monitoring data in 2020–2021. The monitoring and WQII results show that the overall water quality in SNWDP-ER is satisfactory and meets the Class III requirements in China Environmental Quality Standard for Surface Water, except for total nitrogen (TN) which falls into Class V or even worse. The periodic alternations of flow direction between diversion and non-diversion periods tend to deteriorate water quality, particularly in the initial stage of alternations. Water quality appears more stable during the diversion period, and impounding lakes along the project are crucial to water environment restoration in this period. Due to the positive influence brought by the self-purification and environmental carrying in the Luoma Lake, Nansi Lake, and Dongping Lake, water quality exhibits an enhancing trend from upstream to downstream in the Lianghu and Jiaodong reaches. Besides, the monitoring stations in Shandong reach exhibit significant divisional heterogeneity under hierarchical cluster analysis (HCA) with the Nansi Lake and Dongping Lake as the demarcation points, and the results of factor analysis/principal component analysis (FA/PCA) further identified the contributions of mining, shipping, and land use to each section. Based on the findings, the study recommends implementing wastewater discharge control, abandoned mines remediation, and continued water quality monitoring for further maintenance and improvement in SNWDP-ER.

Benign water quality and phytoplankton status during the operation of Guishan offshore wind farm in the Pearl River Estuary, China

Wind power is a clean and renewable source of energy that plays a crucial role in the global effort to combat climate change. Yet, the effects of offshore wind farms on the marine environment remain poorly understood and there is a lack of field data analysis in this area. This study aims to address these gaps by conducting a year-long examination of water quality and phytoplankton communities around the Guishan offshore wind farm (GS-OWF) in the Lingdingyang Bay, Pearl River Estuary, China. The analysis of water quality indicators reveals repelling effect on algae dispersion but no significant contamination resulting from the running of the wind farm over the course of one year. These indicators encompassed various parameters, such as water depth (4.1 − 17.4 m), salinity (16.9 – 28.4 ‰), pH (7.41 – 8.35), temperature (20.5 − 31.2 °C), transparency (⁓ 1.5 m), dissolved oxygen (⁓ 7.5 mg L−1), chemical oxygen demand (⁓ 0.81 mg L−1), chlorophyll-a (14.7 − 0.139 μg L−1), petroleum (0 – 0.0527 mg L−1), and various heavy metals. The cell composition (4 phyla, 158 species, dominated by Bacillariophyta) and density (3 – 1809 cells m−3) demonstrate a healthy phytoplankton community. These results indicate a benign estuary environment after the construction of GS-OWF. This study provides valuable insights into the environmental effects of offshore wind farms, principles for site selection, and the integration of aquaculture convergence with offshore wind farms.

Regulating greenhouse gas dynamics in tidal wetlands: Impacts of salinity gradients and water pollution

Tidal wetlands play a critical role in emitting greenhouse gases (GHGs) into the atmosphere; our understanding of the intricate interplay between natural processes and human activities shaping their biogeochemistry and GHG emissions remains lacking. In this study, we delve into the spatiotemporal dynamics and key drivers of the GHG emissions from five tidal wetlands in the Scheldt Estuary by focusing on the interactive impacts of salinity and water pollution, two factors exhibiting contrasting gradients in this estuarine system: pollution escalates as salinity declines. Our findings reveal a marked escalation in GHG emissions when moving upstream, primarily attributed to increased concentrations of organic matter and nutrients, coupled with reduced levels of dissolved oxygen and pH. These low water quality conditions not only promote methanogenesis and denitrification to produce CH4 and N2O, respectively, but also shift the carbonate equilibria towards releasing more CO2. As a result, the most upstream freshwater wetland was the largest GHG emitter with a global warming potential around 35 to 70 times higher than the other wetlands. When moving seaward along a gradient of decreasing urbanization and increasing salinity, wetlands become less polluted and are characterized by lower concentrations of NO3−, TN and TOC, which induces stronger negative impact of elevated salinity on the GHG emissions from the saline wetlands. Consequently, these meso-to polyhaline wetlands released considerably smaller amounts of GHGs. These findings emphasize the importance of integrating management strategies, such as wetland restoration and pollution prevention, that address both natural salinity gradients and human-induced water pollution to effectively mitigate GHG emissions from tidal wetlands.

Pendampingan Masyarakat Peduli Ekowisata Mangrove di Kawasan Mangrove Tanjung Batu, Kecamatan Sekotong, Kabupaten Lombok Barat, Nusa Tenggara Barat

Assistance to people who care about mangrove ecotourism in mangrove areas is one of the monitoring and evaluation activities to maintain sustainability and increase the effectiveness of ecotourism programs in mangrove areas. The aim of community service activities in the Tanjung Batu mangrove ecotourism area, Sekotong District, West Lombok Regency is a follow-up to the urgency and relevance of the community assistance program caring for mangrove ecotourism in the mangrove area as a strategic step in maintaining the sustainability of the mangrove ecosystem which can improve the welfare of the local community. This service method is carried out through a process of mentoring and community empowerment through several stages, namely: field surveys, interviews, discussions, and formulating solutions for sustainable mangrove ecotourism. The results of service activities show that the Tanjung Batu mangrove ecotourism area, Sekotong District, West Lombok Regency is in good condition with facilities and infrastructure to support tourism activities. Improving the quality of management of mangrove ecotourism areas can be carried out through a strategy of regular monitoring and evaluation of environmental (water) quality conditions, management, organizational structure (pokdarwis), and evaluation of ecotourism management, and involving community participation in sustainable management of Tanjung Batu mangrove ecotourism.