Tap Waters Research Articles

Better Together: Tandem Mass Spectrometry Achieves up to 50 Times Lower Quantification of 62 Disinfection Byproducts in Drinking Water.

Disinfection byproducts (DBPs) are ubiquitous contaminants present in nearly all drinking water and are associated with adverse health effects in human epidemiologic studies. The most toxic DBPs are unregulated and often occur at concentrations well below regulated DBPs; thus, quantification at low parts-per-trillion (ng/L) levels is critical in assessing exposure. We developed a new liquid-liquid extraction-gas chromatography-tandem mass spectrometry (LLE-GC-MS/MS) method with the first analysis by tandem gas chromatography-mass spectrometry of 23 priority unregulated DBPs including 13 haloacetamides, 3 haloacetic acids, 2 haloacetonitriles, 1 haloacetaldehyde, 2 haloketones, and 2 halonitromethanes. When combined with our previous GC-MS/MS method for haloacetic acids and previously reported MS/MS transitions that we optimized for this method, the analysis of 62 regulated and priority unregulated DBPs at lower quantification limits is achieved. Limits of quantification for most DBPs were between 5 and 30 ng/L with r2 > 0.99 and an average of 9 times lower limits of quantification (LOQs) compared to LLE-GC-MS using selected ion monitoring (SIM). Relative standard deviations ranged from 0.7 to 30% for 61 DBPs in spiked samples. This new method was validated using tap waters from four US cities, where individual DBP concentrations ranged from 5 to 126,882 ng/L. This project provides the most comprehensive GC-MS/MS method for DBP analysis to date and is capable of analyzing volatile and semivolatile DBPs across nine different compound classes, including a class not previously analyzed by GC-MS/MS.

Uncovering an effecient binary system as a chemosensor for visual and fluorescence detection of chromium (VI) in water samples

There is an urgent requirement for the development of sensitive and quick sensors to monitor chromium (VI) due to its substantial carcinogenic and mutagenic properties. A coexisting system of coumarin 334 and diphenylcarbazide (C334/DPC) was used in this study as a fluorescent chemosensor to detect Cr(VI) ions. Upon the addition of Cr(VI), a purple chelate complex (Cr(III)-diphenylcarbazone) was produced, which resulted from the quantitative reaction between Cr(VI) ions and diphenylcarbazide (DPC), whereas no interaction between Cr(VI) and coumarin 334 took place. More interestingly, the absorption spectra of purple (Cr(III)-diphenylcarbazone) complex (λmax = 540 nm) were overlapped with emission and excitation spectra of coumarin 334 (λex/em = 453/492), resulting in the efficient quenching of coumarin 334 (C334) via the inner filter effect. Furthermore, the semi-quantitative estimation of Cr(VI) ion concentration may be achieved by visually watching the progressive color transformation of the probe from yellow to red after the addition different concentration of Cr(VI). The calibration plot for determination of Cr(VI) by this method is ranging from 0.048 to 268 μM. DFT calculations were conducted to enrich our understanding about the mechanism of action. This approach demonstrates an excellent selectivity and sensitivity for Cr(VI) including a detection limit of 48 nM. The new sensor was successfully applied to water samples (tap, mineral, and waste waters). The accuracy was confirmed by the atomic absorption spectroscopy.

Discrimination of bottled mineral water from tap water using a Dip-Type colorimetric paper-based sensor array and chemometrics

Mineral water is a natural water that originated from an underground water table, a well, or a natural spring which is considered microbiologically intact. The revenue from the bottled mineral water industry will be USD 342.40 billion in 2023, and it is expected to grow at a compound annual growth rate (CAGR) of 5.24 %. Consequently, the discrimination of original bottled mineral water from tap water is an important issue that requires designing sensors for simple and portable identification of these two types of water. In this work, we have developed a Dip-Type colorimetric paper-based sensor array with three organic dyes (Bromothymol Blue, Bromophenol Blue, and Methyl Red) followed by chemometrics’ pattern recognition methods (PCA and LDA) for discrimination of original bottled mineral waters from tap waters based on differences in ion variety and ion quantity. Forty brands of mineral water and twenty-six Tap water samples from different regions of Shiraz and other Iranian cities were analyzed by this sensor array. Moreover, these experiments were performed in two consecutive years to check the versatility of the sensor with seasonal changes in waters. This sensor array was able to discriminate these two water types from each other with an accuracy of > 95 % based on the analysis of 85 water samples.

Prevalence and Control of Pseudomonas aeruginosa in Tourist Facilities across the Canary Islands, Spain.

Pseudomonas aeruginosa is a common pathogen associated with recreational water facilities and poses risks to public health. However, data on the prevalence of P. aeruginosa in tourist destinations like the Canary Islands, Spain, remain limited. We assessed P. aeruginosa prevalence in 23 tourist facilities from 2016 to 2019. Compliance with water quality standards was evaluated, and 3962 samples were collected and analyzed. We examined different types of recreational water installations, including outer swimming pools, whirlpools, and cold wells. Of the sampled facilities, 31.2% did not comply with the current legislation's parametric values, mainly due to inadequate disinfectant levels, water temperature, and P. aeruginosa presence. The prevalence of P. aeruginosa was 4.8%, comparable to some European countries but lower than others. Cold wells displayed the highest non-compliance rate (89.2%) and yet exhibited a lower P. aeruginosa prevalence (1.9%) than outer swimming pools and whirlpools. Children's presence did not significantly impact P. aeruginosa contamination. Chlorine-based disinfectants are more effective than bromine-based ones in controlling P. aeruginosa. Regional variability in contamination was observed, with Fuerteventura showing lower colonization rates. Disinfectant levels play a critical role in P. aeruginosa control, and maintaining adequate levels is essential, particularly in bromine-treated installations. Our findings provide valuable insights into the prevalence and distribution of P. aeruginosa in recreational waters within tourist facilities. Tailored strategies are needed to ensure water safety in different Spanish regions. Continued monitoring and assessment, combined with artificial intelligence and machine learning, will enable the implementation of targeted interventions to protect the health of recreational water users.

Analysis of Greywater Recovery Systems in European Single-Family Buildings: Economic and Environmental Impacts

This study explores the integration of greywater recovery systems (GRSs) within single-family buildings across European countries. The analysis evaluates the impacts of these systems from multiple perspectives: potable water conservation, economic feasibility, energy consumption, and environmental impact. Employing life cycle cost (LCC) and net present value (NPV) analyses, the research assesses the economic viability of these systems compared to standard water installations. Positive NPV is observed in countries such as Belgium, Germany, Denmark, Finland, and Norway, according to the base scenario. Additionally, the implementation of subsidies can enhance economic incentives for adopting GRSs by reducing the payback period (PBP). Significant findings include reductions in potable water demand by up to 43.0%, and energy savings of up to 42.6% are also observed with the use of GRSs. Additionally, notably lower carbon dioxide emissions (CDEs) were reported, with reductions being directly proportional to the decreases in energy use. This holistic approach aims to establish frameworks for decision-making processes, emphasizing that economic and environmental aspects are mutually complementary and significant.

Performance of pitcher-type POU filters for the removal of 75 PFAS from drinking water: comparing different water sources

This study presents a comprehensive assessment of the performance of popular pitcher-type point-of-use (POU) water filters to remove PFAS contaminants from tap waters. The evaluated filters, Brita (Elite and Standard), ZeroWater, Aquagear, and ClearlyFiltered, were tested for their efficacy in removing 75 targeted PFAS, total organic carbon (TOC), total dissolved solids (TDS), chloride, and sulfate from two Canadian tap waters with background Σ75 PFAS concentrations of 13 and 56 ng/L. Overall, the performances of the filters varied depending on the structure of the filter media, the water source, and the specific contaminants present. ZeroWater was the top performer in the case of total PFAS removal. The volume-weighted average removal of total PFAS after 160 L of filtration using Saint-Donat tap water was 99% for ZeroWater, 99% for ClearlyFiltered, 77% for Aquagear, and 20% for Brita (Elite). In the case of Montreal tap water, which had different water characteristics and lower total PFAS levels, the volume-weighted average removal for PFAS was ≈100% for ZeroWater, 96% for ClearlyFiltered, 60% for Aquagear, 48% for Brita (Elite), and 38% for Brita (Standard). Both laboratory and home tests involving ZeroWater filters yielded similar high-performance results using Montreal tap water. Although ZeroWater exhibited high PFAS removal (99%) in Saint-Donat water, TDS and TOC desorption and a significant drop in pH were observed after 80 L, a phenomenon which was explained by the higher total concentration of anions in this water. In contrast, no desorption was observed in Montreal tap water for TDS and TOC due to the lower concentrations of anions. The Aquagear filter demonstrated an unusual increase in concentrations of sulfate after the initial 20 L, which needs further evaluation. This study discusses individual filter performance, the influence of tap water characteristics, and the potential to meet the new NSF guidelines, which provides valuable insights for consumers seeking to choose an appropriate easy-to-use water filtration system to ensure safe and clean drinking water in different regions.

Bartenders in Marrakesh between the past and the present

The city of Marrakesh is among the oldest Moroccan cities. Since its founding by the Almoravid Emir Youssef Ibn Tashfin, it has played prominent roles in political, cultural and social life. It has also been, by virtue of its political location, a source of great radiance and an important cultural center that has resulted in a rich cultural heritage that has lasted for many centuries and been passed down to generations. Different. Irrigations constituted one of the most important water installations that marked the history of water architecture in Marrakesh. This is evidence that the latter had an advanced system for distributing water, especially irrigation technology, which is considered a vital facility that falls within the urban fabric of the city. It is spread in multiple locations such as hamlets, and there are some paths that still carry the path. Watering. Irrigation is the end of a network of mechanisms and facilities that supplied the city with water and made it consumable, starting from its natural sources of extraction, passing through the waterways, collecting, and storing it in tanks, and finally distributing it to the city through canals and waterways, bringing it to irrigation, the meeting point between the consumer and this vital natural product.

Utilizing big data to determine the temperature dependency of Legionella in hot water systems

ABSTRACT Domestic hot water installations provide an ideal habitat for Legionella spp. and pose a potential risk of human infection. Heating the water is considered the major preventive measure against Legionella contamination. Our study aimed to understand better the relationships between hot water temperatures and Legionella spp. occurrence within such systems. We utilized routine monitoring data from public and apartment buildings, comprising 292,937 data sets. We employed the analysis of variance, receiver operating characteristic analysis, and relative probability of occurrence to quantitatively assess statistical relationships. In the case of supply flow (SF) and return flow (RF), i.e. near the water heater, water temperature strongly regulates Legionella spp. growth. Below calculated tipping points (SF: 56 °C, RF: 53 °C), the relative probability of Legionella spp. occurrence is 18.7 and 7.5 times higher, respectively. For peripheral samples, the relationship between temperature and Legionella spp. occurrence is less pronounced. Additionally, statistical relationships between central and peripheral temperatures, as well as between central temperatures and peripheral Legionella spp. concentrations within one system, were weak or zero, respectively. Thus, the central temperature regime of hot water systems alone is insufficient to control the occurrence of Legionella spp. in the periphery.

Nanowire-assisted electroporation via inducing cell destruction for inhibiting formation of VBNC bacteria: Comparison with chlorination

The induction of viable but nonculturable (VBNC) bacteria with cellular integrity and low metabolic activity by chemical disinfection causes a significant underestimation of potential microbiological risks in drinking water. Herein, a physical Co3O4 nanowire-assisted electroporation (NW-EP) was developed to induce cell damage via the locally enhanced electric field over nanowire tips, potentially achieving effective inhibition of VBNC cells as compared with chemical chlorination (Cl2). NW-EP enabled over 5-log removal of culturable cell for various G+/G- bacteria under voltage of 1.0 V and hydraulic retention time of 180 s, and with ∼3–6 times lower energy consumption than Cl2. NW-EP also achieved much higher removals (∼84.6 % and 89.5 %) of viable Bacillus cereus (G+) and Acinetobacter schindleri (G-) via generating unrecoverable pores on cell wall and reversible/irreversible pores on cell membrane than Cl2 (∼28.6 % and 41.1 %) with insignificant cell damage. The residual VBNC bacteria with cell wall damage and membrane pore resealing exhibited gradual inactivation by osmotic stress, leading to ∼99.8 % cell inactivation after 24 h storage (∼59.4 % for Cl2). Characterizations of cell membrane integrity and cell morphology revealed that osmotic stress promoted cell membrane damage for the gradual inactivation of VBNC cells during storage. The excellent adaptability of NW-EP for controlling VBNC cells in DI, tap and lake waters suggested its promising application potentials for drinking water, such as design of an external device on household taps.

A Benchmark Data Set for Long-Term Monitoring in the eLTER Site Gesäuse-Johnsbachtal

This paper gives an overview over all currently available data sets for the European Long-term Ecosystem Research (eLTER) monitoring site Gesäuse-Johnsbachtal. The site is part of the LTSER platform Eisenwurzen in the Alps of the province of Styria, Austria. It contains both protected (National Park Gesäuse) and non-protected areas (Johnsbachtal). Although the main research focus of the eLTER monitoring site Gesäuse-Johnsbachtal is on inland surface running waters, forests and other wooded land, the eLTER whole system (WAILS) approach was followed in regard to the data selection, systematically screening all available data in regard to its suitability as eLTER’s Standard Observations (SOs). Thus, data from all system strata was included, incorporating Geosphere, Atmosphere, Hydrosphere, Biosphere and Sociosphere. In the WAILS approach these SOs are key data for a whole system approach towards long term ecosystem research. Altogether, 54 data sets have been collected for the eLTER monitoring site Gesäuse-Johnsbachtal and included in the Dynamical Ecological Information Management System – Site and Data Registry (DEIMS-SDR), which is the eLTER data platform. The presented work provides all these data sets through dedicated data repositories for FAIR use. This paper gives an overview on all compiled data sets and their main properties. Additionally, the available data are evaluated in a concluding gap analysis with regard to the needed observation data according to WAILS, followed by an outlook on how to fill these gaps.

Preconcentrating extractive polymeric network in paper-based sensing of copper

The concept of using an extractive polymeric sensing network on a paper-based substrate for the pretreatment of samples in the colorimetric analysis of heavy metals is demonstrated with the determination of Cu2+ in aqueous samples. The newly developed paper-based device combines the advantages of both liquid–liquid extraction-based separation and the analytical capabilities of microfluidic paper-based analytical devices (μPADs). The preconcentrating extractive polymeric network composed of 53.5 wt% poly(vinyl chloride) (PVC), 45 wt% extractant (di-(2-ethylhexyl)phosphoric acid (D2EHPA)) and 1.5 wt% dye (1-(2′-pyridylazo)-2-naphthol (PAN)), coated on filter paper, shows good water-wicking properties, allowing the transmission of high sample volumes. This results in significant analyte preconcentration. The extractant (D2EHPA) selectively binds Fe3+ and Zn2+ which otherwise will compete with Cu2+ in its colour reaction with PAN at the chosen pH of 3.0. The device’s capacity to process higher sample volumes resulting in higher sensitivity is increased by the integration of several filter paper absorption layers. The optimized device is characterized by a limit of detection (LOD) for tap and environmental waters of 3.4 and 9.6 µg/L, respectively; stability of 51 days if stored in a refrigerator; and total analysis time (from sample insertion to colour detection) of less than 5 min.

In-syringe homogeneous liquid-phase microextraction followed by filtration-based phase separation for on-site extraction of chloroanilines from water samples.

This study introduces a new in-syringe homogeneous liquid-phase microextraction method for the rapid on-site extraction of chloroanilines from water samples. Extraction was performed using a plastic syringe, eliminating the use of any electrical power source. Di-(2-ethylhexyl) phosphoric acid (DEHPA) served as the extractant. The process initially involved dissolving DEHPA in an alkaline solution to obtain a homogeneous solution. Subsequently, the sodium salt of DEHPA was precipitated by salting-out, and the resulting heterogeneous mixture was filtered using a syringe filter. The precipitate containing the analytes was then dissolved in methanol for analysis by high-performance liquid chromatography. Under optimal conditions, extraction recovery for chloroanilines ranged from 26% to 71%. Method linearity was evaluated within a concentration range of 1.0-100µg/L, resulting in coefficients of determination exceeding 0.9987 for all analytes. Method detection limits ranged from 0.28 to 0.41µg/L. Intra and inter-day precision values were below 9.5% and 10.8%, respectively. The developed method was applied to determine chloroanilines in real waters, yielding acceptable recoveries ranging from 80% to 109% for spiked tap, rain, and stream waters. Additionally, the method was successfully employed for on-site extraction of target contaminants, demonstrating no statistically significant differences compared to laboratory results.

Dye-assisted analysis of fluoride in water using UV–visible spectrophotometry: a preliminary study

ABSTRACT Dye-assisted method for the analysis of fluoride content of water has been developed in this study using dyes obtained from some flowering plants. This was done to evaluate the potentials of locally accessible dyes in spectrophotometrically detecting F– levels in fluoride-containing water samples. Dye solutions obtained from scarlet jungle flame, Hibiscus flower, Peacock flower or Barbados pride, Royal poinciana, Pink bauhinia, Barbados lily, or Easter lily were adopted to monitor absorbance and corresponding concentrations of serially prepared F− concentrations in a range of 0.001–0.012 ppm. Dye from the Hibiscus flower gave an optimal performance with R2 = 0.9792. Using this dye, the F– content in water samples obtained from tap waters from Moremi Estate, Modomo, Asherifa, Postgraduate Hall of Obafemi Awolowo University, Ile-Ife, and a well water sample from Modomo gave 0.052, 0.053, 0.053, 0.058, and 0.061 ppm, respectively. A comparison of these values indicated that all the water samples monitored were safe for human consumption without experiencing health challenges as the maximum F– limit for potable water recommended by WHO was not exceeded. This study concluded that dye from Hibiscus flower could satisfactorily assist in monitoring F– content in water where ion-selective electrodes are not readily accessible.

Lentils/urea as precursors for profound S and N doping of carbon dots for selective sequential determination of Hg(II) and S(II) in food and environmental samples

In this article, we described a new platform for probing toxic pollutants, namely Hg2+ and S2-, in aquatic environment by tracing the “on–off-on” fluorescence signals of quantum dots. To achieve this, red lentils and urea, as natural precursors, were utilized as sources of S and N doping, respectively, to fabricate blue fluorescent carbon quantum dots, namely, lentils/urea quantum dots (LUQDs) with good quantum yield and plentiful S-doping. In the present work, the quality-by-design (QbD) strategy was applied to control and select the optimum conditions for the microwave-aided synthesis of the carbon dots. LUQDs exhibit excitation-dependent emissions, where the maximum fluorescence emission was at 360 nm after excitation at 300 nm. During the detection step, the fluorescence of LUQDs is quenched by the incorporation of Hg2+ over the range of 0.50–70.0 μM. Next, S2- reacts with Hg2+, resulting in turning on the fluorescence emission of LUQDs in the range of 10.0–150.0 µM.The method was applied for the detection of both Hg2+ and S2- in tap, sewage, and river water samples with a recovery rate ranging between 98.96 % and 101.26 %; in addition, Hg2+ was detected in canned Tuna samples with a recovery of 98.70 %. Furthermore, the greenness of the developed method was confirmed through various greenness metrics.

Wearable Multi‐Plied Potentiometric Sensor based on Carbon Nanotube Yarn for Electronic Tongue

AbstractWearable ion‐selective potentiometric sensors have received considerable interest in enabling taste sensing in robots and for monitoring abnormal conditions, such as poor water quality, spoiled food (freshness), and microbial contamination. Despite advances in wearable ion‐selective sensors, the production of a stretchable and miniaturized ion‐selective sensor to detect various ions remains a challenge for practical applications. Herein, a stretchable multi‐ply potentiometric sensor is reported based on ion‐selective coiled yarn (ISCY) with Carbon nanotube. Three types of ISCYs show high sensitivity and selectivity toward a specific target ion, such as K+, Na+, and H+. The sensitivity and selectivity are maintained even at 27% strain and under mechanical deformation, such as being bent by 180° or tied into a knot. Furthermore, an attempt is made to miniaturize the sensor into a single fiber by plying three types of ISCYs and a reference electrode together. This multi‐ion potentiometric sensor is successfully woven into fabrics, such as clothes or gloves, and exhibits a functional sensing performance in various water‐based solutions (sea, river, tap, and distilled waters) and fruit juices as practical applications. These results suggest that this potentiometric sensor has a high potential application as a taste sensor and a monitoring sensor in an electronic tongue.

Electrochemical Detection of Bisphenol A Based on Gold Nanoparticles/Multi-Walled Carbon Nanotubes: Applications on Glassy Carbon and Screen Printed Electrodes.

Bisphenol A (BPA) has been classified as an endocrine-disrupting substance that may cause adverse effects on human health and the environment. The development of simple and sensitive electrochemical biosensors is crucial for the rapid and effective quantitative determination of BPA. This work presents a study on electrochemical sensors utilizing gold nanoparticle-modified multi-walled carbon nanotubes (CNT/AuNPs). Glassy carbon electrodes (GCEs) and screen-printed electrodes (SPEs) were conveniently modified and used for BPA detection. AuNPs were electrodeposited onto the CNT-modified electrodes using the galvanostatic method. The electrodes were properly modified and characterized by using Raman spectroscopy, cyclic voltammetry (CV), and electrochemical impedance analysis (EIS). The electrochemical response of the sensors was studied using differential pulse voltammetry (DPV) and constant potential amperometry (CPA) for modified GCE and SPE electrodes, respectively, and the main analytical parameters were studied and optimized. Problems encountered with the use of GCEs, such as sensor degradation and high limit of detection (LOD), were overcome by using modified SPEs and a flow injection device for the measurements. Under this approach, an LOD as low as 5 nM (S/N = 3) was achieved and presented a linear range up to 20 μM. Finally, our investigation addressed interference, reproducibility, and reusability aspects, successfully identifying BPA in both spiked and authentic samples, including commercial and tap waters. These findings underscore the practical applicability of our method for accurate BPA detection in real-world scenarios. Notably, the integration of SPEs and a flow injection device facilitated simplified automation, offering an exceptionally efficient and reliable solution for precise BPA detection in water analysis laboratories.

Dispersive micro-solid phase extraction (D-μSPE) of nickel on activated nanodiamonds@Bi2WO6 nanocomposite from water and food samples

This study presents an original nano-sorbent using activated nanodiamonds@Bi2WO6 to separate and enrich nickel ions from water and food samples. FTIR, XRD, FE-SEM, FE-SEM-EDX, EDS-TEAM, TGA, and BET were used to characterize the nanocomposite. It has a large surface area, active functional groups, and better reactivity. Ni(II) ions were determined as Ni(II)-PADAP chelates using UV-VIS spectroscopy. The parameters were studied and optimized, including pH (6), eluent type and volume (1 mL), ligand quantity (10 μg), sorbent dosage (20 mg), and contact time (1 min). The method has a low limit of detection (LOD) of 1.6 μg L−1, a limit of quantification (LOQ) of 5.3 μg L−1, a relative standard deviation of 4.5%, and a preconcentration factor of 10. The method was validated by applying to certified reference materials (BCR estuarine water 505 and 1573a NIST). The method was successfully applied to tap waters, industrial waste waters, and vegetables.

Persistence of viable but nonculturable Legionella pneumophila state in hospital water systems: A hidden enemy?

There is little evidence of the long-term consequences of maintaining sanitary hot water at high temperatures on the persistence of Legionella in the plumbing system. The aims of this study were to describe the persistence and genotypic variability of L. pneumophila in a hospital building with two entirely independent hot water distribution systems, and to estimate the thermotolerance of the genotypic variants by studying the quantity of VBNC L. pneumophila. Eighty isolates from 55 water samples obtained between the years 2012–2017 were analyzed. All isolates correspond to L. pneumophila serogroup 6. The isolates were discriminated in four restriction patterns by pulsed-field gel electrophoresis. In one installation, pattern A + Aa predominated, accounting for 75.8 % of samples, while the other installation exhibited pattern B as the most frequent (81.8 % of samples; p < 0.001). The mean temperature of the isolates was: 52.6 °C (pattern A + Aa) and 55.0 °C (pattern B), being significantly different. Nine strains were selected as representative among patterns to study their thermotolerance by flow-cytometry after 24 h of thermic treatment. VBNC bacteria were detected in all samples. After thermic treatment at 50 °C, 52.0 % of bacteria had an intact membrane, and after 55 °C this percentage decreased to 23.1 %. Each pattern exhibited varying levels of thermotolerance. These findings indicate that the same hospital building can be colonized with different predominant types of Legionella if it has independent hot water installations. Maintaining a minimum temperature of 50 °C at distal points of the system would allow the survival of replicative L. pneumophila. However, the presence of Legionella in hospital water networks is underestimated if culture is considered as the standard method for Legionella detection, because VBNC do not grow on culture plates. This phenomenon can carry implications for the Legionella risk management plans in hospitals that adjust their control measures based on the microbiological surveillance of water.

THE RELATIONSHIP BETWEEN ORGANIC MATERIAL CONTENT IN SEDIMENTS AND THE ABUNDANCE OF EPIPELIC DIATOMS IN THE INTERTIDAL ZONE OF THE WATERS OF DUMAI CITY, RIAU PROVINCE

This research was conducted in March 2023, located in Koneng Beach, Dumai City. The purpose of this study was to determine the organic matter content and abundance of epipelic diatoms vertically and to analyze the relationship between the organic matter content in sediments and the abundance of epipelic diatoms vertically in the intertidal area of Dumai City Waters. The method used is the survey method. The sampling point is determined using a purposive sampling method. Sampling of epipelic diatoms was carried out using a modified corer, which was then brought to the laboratory to identify and calculate the abundance of diatoms and the sediment samples to calculate the content of organic matter and sediment fractions. Water quality measurements accompanied sampling with a brightness value of 0.57 m, temperature of 33 °C, current speed of 0.33 m/s, salinity of 28 ppt, and pH of 8.13. The results of the analysis of organic matter are 2.55 – 13.38%. The results of the sediment fraction analysis show that the research location is dominated by sandy silt. Nineteen genera of epipelic diatoms were found in the waters of Koneng Beach, Dumai City, with abundance values between 5,291–39,983 ind/cm2. The one-way ANOVA test results obtained an average value of 0.000, meaning there is a significant difference in the abundance of epipelic diatoms between the sediment layers. The results of the linear regression test showed that the effect of sediment organic matter on the abundance of epipelic diatoms was 50.85%.

Fostering Stewardship in Managing Fisheries and Aquatic Resources in the Lens of Green Criminology

Illegal fishing imperils Gulf ecosystems, prompting this qualitative study, rooted in green criminology and purposive sampling, to explore stewardship in fisheries and aquatic resource management. Police officers (Bantay Dagat), BFAR representatives, Barangay Officials, and Fisherfolks were interviewed. This study revolved around three main thrusts: (1) common law violations relative to the fishery and aquatic resources law violations; (2) the reasons/motivational factors of engaging in the fishery and aquatic resources law violations; and (3) measures on how the community can foster stewardship in managing fisheries and aquatic resources. The findings proved that the illegal fishing activities in municipal waters and marine protected areas were done for higher income and economic sustenance but posed various threats to the sustainability of aquatic and fishery resources and the environment in Leyte Gulf. The study also found that the community can foster stewardship through participatory enforcement of aquatic and fishery laws and programs and the provisions of equipment and resources needed for more effective patrol and surveillance of marine waters to prevent and combat illegal fishing. Keywords: Green Criminology, Illegal Fishing, Stewardship, Leyte Gulf