High Turbidity Levels Research Articles

Electrocoagulation treatment of wastewater collected from Haldia industrial region: Performance evaluation and comparison of process optimization

This study investigates the treatment of oil-contaminated wastewater with high levels of inorganic substances, suspended solids and turbidity, collected from the Haldia industrial region of India in February 2023. The wastewater, originating from industries such as chemical, petrochemical, textile, and battery manufacturing, presents a complex pollutant load that challenges traditional treatment methods. Electrocoagulation was employed as the treatment technique, with process optimization conducted using Box-Behnken design (BBD) and central composite design (CCD) for key parameters: pH, initial oil concentration, current density, and electrolysis time. The study comprehensively examined the effects of these parameters on turbidity removal. The optimal conditions were determined to be a pH of 7.5, an initial oil concentration of 275 mg/L, a current density of 17.5 mA/cm², and an electrolysis time of 20 min. Under these conditions, CCD outperformed BBD, achieving a desirability score of 93 % compared to 80 % for BBD. The process successfully reduced turbidity from 450 NTU to 56 NTU and total suspended solids (TSS) from 300 mg/L to 102 mg/L. The operation cost of the process was found to range from ₹0.904/m³ to ₹2.71/m³ as the electrolysis time increased from 0.17 to 0.5 h. The study presents a viable solution for industrial wastewater treatment in this region, aligning with the United Nations Sustainable Development Goal (UN SDG) 2030. Additionally, combining electrocoagulation with membrane filtration may enhance comprehensive pollutant removal.

Ecosystem links: Anthropogenic activities, environmental variables, and macrophytes structure snail preferences in man-made waterbodies

Freshwater snails act as obligate intermediate hosts for trematode parasites that cause trematodiases threatening public and veterinary health, and biodiversity conservation. While interest in snail control for trematodiases has re-emerged, their ecology remains poorly understood. We examined the relationship between ecosystem indicators – such as environmental variables, macroinvertebrates, macrophytes, and land use – and their correlation with snail abundance, diversity, and infection prevalence in 19 man-made ponds in eastern Zimbabwe. In total, 926 freshwater snails from 10 species were collected, with 547 individuals belonging to five schistosome-competent species: Bulinus tropicus, Bulinus truncatus, Bulinus globosus, Bulinus forskalii, and Biomphalaria pfeifferi. The remaining 379 snails comprised Radix natalensis, Gyraulus sp., and the exotic invasive species Melanoides tuberculata, Pseudosuccinea columella, and Physella acuta. Six cercarial types – mammalian schistosomes, avian schistosomes, longifurcate pharyngeates, echinostomes, amphistomes, and xiphidiocercariae – were isolated from 104 out of 926 snails (11.2 %). PCR revealed a significantly higher infection rate, with 70.2 % of snails testing positive for trematodes. Snail taxon diversity and infection rate significantly varied across land use types, with the lowest values observed in the commercial tobacco farm section, highlighting the potential adverse effects of agriculture on biodiversity. Ponds with extensive Lagarosiphon major (oxygen weed) coverage appeared to facilitate the presence and abundance of P. acuta and P. columella. Schistosome-competent snails such as B. truncatus and B. tropicus seemed to favor shallow water depths and more eutrophic sites characterized by high levels of nitrates, phytoplankton biomass, turbidity, and phycocyanin. These ponds were predominantly associated with the emergent macrophyte Cladium mariscus, revealing a potential association with important intermediate snail hosts. In conclusion, our study emphasizes the complex interplay among environmental factors, macrophyte composition, land use, and the abundance, diversity, and infection prevalence of freshwater snails, offering insights into potential strategies for targeted snail control and disease management in man-made waterbodies.

Impact of parametric seasonal variations on water quality in the Crocodile River and Inyaka Dam in the Mpumalanga Province, South Africa

This study assessed seasonal variations in water quality and their impact on the Inyaka Dam and Crocodile River in Mpumalanga Province, South Africa. A total of 206 water samples were collected across four seasons to analyse parameters including pH, turbidity, electrical conductivity (EC), temperature, Manganese (Mn), Iron (Fe), phosphate (PO43−), nitrate-nitrogen (NO3-N), E. coli, total coliforms, faecal streptococci, and Bifidobacteria. Principal component analysis (PCA) and Pearson correlation identified major pollutants and their seasonal variations, while cluster analysis grouped water quality by parameter fluctuations.Findings indicated that water quality in both the Inyaka Dam and the Crocodile River exceeded permissible limits. In the Inyaka Dam, summer rainfall (202.68 mm) spurred microbial growth, including E. coli and Bifidobacteria, while winter saw elevated levels of PO43−, EC, Fe, and NO3-N. The Crocodile River exhibited its poorest water quality in summer, with high levels of conductivity, turbidity, Fe, Mn, and NO3-N, driven largely by rainfall. Winter pollution in the river was marked by E. coli, PO43−, total coliforms, NO3-N, and Bifidobacteria.The study highlights significant pollution in the Crocodile River, particularly in summer, linked to rainfall and effluent discharges. Microbial pollution persisted across seasons, influenced by both weather and point-source contamination. The winter season exacerbated water quality deterioration in the Crocodile River due to reduced flow, while Inyaka Dam's winter pollution was attributed to lake stratification.

Development of a limestone-based ballasted material for enhanced co-removal of turbidity and fluoride from coal mine water: An efficacy study

The rapid progression of coal mining technology in recent years has resulted to the discharge of mine water with excessively high levels of turbidity and fluoride, presenting a complex contamination issue. This study develop an innovative limestone-based ballasted material, integrating it with ballasted flocculation technology. The synergistic effects of surface flocculation and adsorption have enabled the simultaneous and efficient removal of high concentrations of turbidity and fluoride. The influence of various parameters, including the dosage of the coagulant, flocculant, ballasted material, and the stability under long-term continuous operation, on the performance of this new technology was investigated. Findings indicate that an increase in the dosage of the coagulant, polyaluminum chloride (PAC), positively affects the removal of turbidity and fluoride ions, with an optimal dosage of 60 mg/L. The addition of polyacrylamide (PAM) showed that both conventional and ballasted coagulation techniques exhibit an initial increase followed by a decrease in turbidity removal efficiency, and an ascending trend in fluoride removal efficiency, with an optimal PAM dosage of 1.0 mg/L. The dosage of the new ballasted material was determined based on the initial water turbidity and fluoride concentrations, an increase in its dosage led to a progressive reduction in effluent turbidity and a corresponding increase in fluoride removal. A 30-day continuous operation confirmed the stability of the new process, with a treatment cost of approximately 2.67 $/t. The pseudo-first-order kinetic model and the Langmuir adsorption isotherm equation provided satisfactory fits to the treatment data, suggesting that both conventional and ballasted coagulation involve a combination of surface adsorption and intraparticle diffusion mechanisms for the removal of turbidity and fluoride.

Combined Effects of Local and Regional Drivers on Oyster Spat Density and Growth in Eastern Australia

Up to 85% of shellfish reefs have been lost worldwide, resulting in declining ecosystem services, and increasing restoration demand. However, more information regarding the conditions which maximise oyster settlement and growth is required to optimise restoration. We deployed oyster settlement tiles at 21 intertidal sites throughout Moreton Bay, Australia; a region where > 96% of rock oyster reefs are lost and demand for restoration is high. We quantified effects of variables describing the spatial (from GIS), local habitat (using quadrats and water quality measures), and oyster predator (using underwater videography) characteristics of sites on oyster density and size on tiles. Oyster density was highest at sites with intermediate predator abundance and temperature, highest nearby invertebrate cover, and low and high values of turbidity and nearby rock and algae cover. Conversely, oyster size was highest at sites with intermediate predator density, higher fish species richness and turbidity, and lowest temperatures. Together, this showed that optimal restoration requires sites with 22 to 23 °C average water temperatures, between 10 and 15 oyster predators, and either low (< 2 NTU) or high (> 6 NTU) turbidity levels. Notably, we observed multiple peaks for several variables, suggesting the potential presence of multiple cryptic oyster species on settlement tiles. We found that oysters shared preferred environmental conditions with polychaetes, coralline algae, and tunicates, and were more prevalent and abundant at sites with lower turf algae, barnacle, and mussel cover. Identifying environmental variables influencing oyster population distribution, settlement, and growth can guide the selection and approach of oyster restoration sites.

A proposed methodology to evaluate the influence of climate change on drinking water treatments and costs

Drinking water (DW) production treatments can be affected by climate change, in particular intense rainfall events, having an impact on the availability and quality of the water source. The current study proposes a methodology for the evaluation of the costs of the different treatment steps for surface water (SW) and groundwater (GW), through the analysis and quantification of the main cost items. It provides the details to count for strong variations in the key quality parameters of inlet water following severe rainfalls (namely turbidity, iron, manganese, and E. coli). This methodology is then applied to a large drinking water treatment plant (DWTP) in Italy, which treats both SW, around 70 %, and GW, around 30%. It discusses the overall DW production costs (from 7.60 c€/m3 to 10.43 c€/m3) during the period 2019–2021 and analyzes the contributions of the different treatment steps in water and sludge trains. Then it focuses on the effects on the treatments of significant variations in SW turbidity (up to 1863 NTU) due to intense rainfalls, and on the daily costs of DW with respect to the average (baseline) costs evaluated on the annual basis. It emerges that, when SW has low turbidity levels, the energy-based steps have the biggest contribution on the costs (final pumping 22 % for SW and 10 % for GW, withdrawal 15 % and 14 %, respectively), whereas at very high turbidity levels, sludge greatly increases, and its treatment and disposal costs become significant (up to 14 % and 50 %). Efforts are being made to adopt the best strategies for the management of DWTPs in these adverse conditions, with the aim to guarantee potable water and optimize water production costs. A mitigation measure consists of increasing GW withdrawal up to the authorized flow rate, thus reducing SW withdrawal. In this context, the study is completed by discussing the potential upgrading of the DWTP by only treating GW withdrawn from riverbank filtration. The DW production cost would be 7.76 c€/m3, which is lower than that seen for the same year (2021) with the current plant configuration (8.32 c€/m3).

Turbidity effects on prey consumption and survival of larval European smelt (Osmerus eperlanus)

The anadromous European smelt (Osmerus eperlanus) plays a key role in food webs of many riverine ecosystems in Europe. However, population sizes in several German rivers (e.g. Elbe or Weser rivers) have diminished drastically over the past decade. Turbidity has been considered one of the stressors affecting the successful recruitment of European smelt, as their early life stages may be particularly sensitive to changes in the abiotic environment. In this study, we investigated whether prey consumption and survival of European smelt larvae would be negatively affected by an acute exposure to elevated turbidity. We reared the larvae in the laboratory and exposed them in four separate trials (18 to 26 days post hatch, 9.5 ± 0.8 mm standard length, mean ± SD) to six turbidity levels (0–500 NTU, nephelometric turbidity units). We found that prey uptake increased at low turbidity levels and decreased at high turbidity levels, with an optimum between 100 and 200 NTU. Survival started to decrease at turbidity levels above 300 NTU. In addition, we conducted a systematic literature analysis in which we found that prey consumption of larval and juvenile fishes had been tested across a wide range of turbidity levels, mostly using pelagic (e.g. planktonic) prey items, with more studies focusing on perciform fishes and juvenile rather than larval life stages. Our empirical findings contribute to establishing thresholds for optimal larval European smelt performance under increased turbidity and provide valuable information for developing mechanistic models that assess potential consequences for European smelt recruitment dynamics.

Monitoring Dissolved Oxygen Concentrations in the Coastal Waters of Zhejiang Using Landsat-8/9 Imagery

The Zhejiang coastal waters (ZCW), which exhibit various turbidity levels, including low, medium, and high turbidity levels, are vital for regional ecological balance and sustainable marine resource utilization. Dissolved oxygen (DO) significantly affects marine organism survival and ecosystem health, yet there is limited research on remote sensing monitoring of DO in the ZCW, and the underlying mechanisms are unclear. This study addresses this gap by utilizing high-resolution Landsat 8/9 imagery and sea surface temperature (SST) data to develop a multiple linear regression (MLR) model for DO estimation. Compared to previous studies that utilize remote sensing band reflectance data as inputs, the results show that the red and blue bands are more suitable for establishing DO inversion models for such water bodies. The model was applied to analyze variations in the DO concentrations in the ZCW from 2013 to 2023, with a focus on Hangzhou Bay (HZB), Xiangshan Bay (XSB), Sanmen Bay (SMB), and Yueqing Bay (YQB). The temporal and spatial distributions of DO concentrations and their relationships with environmental factors, such as chlorophyll-a (Chl-a) concentrations, total suspended matter (TSM) concentrations, and thermal effluents, are analyzed. The results reveal significant seasonal fluctuations in DO concentrations, which peak in winter (e.g., 9.02 mg/L in HZB) and decrease in summer (e.g., 6.83 mg/L in HZB). Changes in the aquatic environment, particularly in the thermal effluents from the Sanmen Nuclear Power Plant (SNPP), significantly decrease coastal dissolved oxygen (DO) concentrations near drainage outlets. Chl-a and TSM directly or indirectly affect DO concentrations, with notable correlations observed in XSB. This study offers a novel approach for monitoring and managing water quality in the ZCW, facilitating the early detection of potential hypoxia issues in critical zones, such as nuclear power plant heat discharge outlets.

Can Turbidity Data from Remote Sensing Explain Modelled Spatial and Temporal Sediment Loading Patterns? An Application in the Lake Tana Basin

Understanding the spatial and temporal patterns of sediment loading in water bodies is crucial for effective water quality management. Remote sensing (RS) has emerged as a valuable and reliable tool for monitoring turbidity, which can provide insights into sediment dynamics in water bodies. In this study, we investigate the potential of turbidity data derived from RS to explain simulated spatial and temporal sediment loading patterns in the Lake Tana basin, Ethiopia. Utilizing existing RS lake turbidity data from Copernicus Global Land Service (CGLS) and simulated seasonal and multiyear trends of river sediment loadings into Lake Tana from the Soil and Water Assessment Tool (SWAT + model), we estimate correlations at different river inlets into Lake Tana. The results reveal a strong positive correlation (R2 > 0.66) between the multiyear monthly average sediment load from inflow rivers and RS lake turbidity at most river inlets. This indicates that the simulated river sediment loads and lake turbidity at river inlets exhibit similar seasonal patterns. Notably, higher turbidity levels are observed at the river inlet with the highest sediment load export. These findings highlight the potential of RS turbidity products in characterizing temporal and spatial patterns of sediment loadings, particularly in data-scarce regions, contributing to a better understanding of water quality dynamics in such areas.

Impact of turbidity on the gill morphology and hypoxia tolerance of eastern sand darter (Ammocrypta pellucida).

Anthropogenic stressors such as agriculture and urbanization can increase river turbidity, which can negatively impact fish gill morphology and growth due to reduced oxygen in the benthic environment. We assessed the gill morphology, field metabolic rate (FMR), and two hypoxia tolerance metrics (oxygen partial pressure at loss of equilibrium, PO2 at LOE, and critical oxygen tension, Pcrit) of eastern sand darter (Ammocrypta pellucida), a small benthic fish listed as threatened under the Species at Risk Act in Canada, from rivers in southern Ontario. Field trials were conducted streamside in the Grand River (August 2019; mean NTU 8) and in the comparatively more turbid Thames River (August 2020; mean NTU 94) to test the effect of turbidity on each physiological endpoint. Gills were collected from incidental mortalities and museum specimens, and were assessed using hematoxylin and eosin and immunofluorescent staining. The between-river comparison indicated that turbidity significantly increased interlamellar space and filament width but had no significant influence on other gill morphometrics or FMR. Turbidity significantly increased PO2 at LOE (i.e., fish had a lower hypoxia tolerance) but did not significantly impact Pcrit. Therefore, although turbidity influences hypoxia tolerance through LOE, turbidity levels were not sufficiently high in the study rivers to contribute to measurable changes in gill morphology or metabolism in the wild. Determining whether changes in gill morphology or metabolism occur under higherturbidity levels would help resolve the ecological importance of turbidity on species physiology in urban and agricultural ecosystems.

Biomass estimations of cultivated kelp using underwater RGB images from a mini-ROV and computer vision approaches

Seaweed farming is the fastest-growing aquaculture sector worldwide. As farms continue to expand, automated methods for monitoring growth and biomass become increasingly important. Imaging techniques, such as Computer Vision (CV), which allow automatic object detection and segmentation can be used for rapid estimation of underwater kelp size. Here, we segmented in situ underwater RGB images of cultivated Saccharina latissima using CV techniques and explored pixel area as a tool for biomass estimations. Sampling consisted of underwater imaging of S. latissima hanging vertically from a cultivation line using a mini-ROV. In situ chlorophyll a concentrations and turbidity (proxies for phytoplankton and particle concentrations) were monitored for water visibility. We first compared manual length estimations of kelp individuals obtained from the images (through manual annotation using ImageJ software). Then, we applied CV methods to segment and calculate kelp area and investigated these measurements as a robust proxy for wet weight biomass. A strong positive linear correlation (r2 = 0.959) between length estimates from underwater image frames and manual measurements from the harvested kelp was observed. Using unsupervised learning algorithms, such as mean shift clustering, colour segmentation and adaptive thresholding from the OpenCV package in Python, kelp area was segmented and the number of individual pixels in the contour area was counted. A positive power relationship was found between length from manual measurements with CV-derived area (r2 = 0.808) estimated from underwater images. Likewise, CV-derived area had a positive power relationship with wet weight biomass (r² = 0.887). When removing data where visibility was poor due to high turbidity levels (mid-June), the power relationship was stronger between CV-derived area estimates and the field measurements (r² = 0.976 for wet weight biomass and r² = 0.979 for length). These results show that robust estimates of cultivated kelp biomass in situ are possible through kelp colour segmentation. However, we demonstrate that the quality of CV post-processing and accuracy of the model are highly dependent of environmental conditions (e.g. turbidity and chlorophyll a concentrations). The establishment of these technologies has the potential to offer scalability of production, efficient real-time monitoring of sea cultivation and improved yield predictions.

African polyvalent antivenom can maintain pharmacological stability and ability to neutralise murine venom lethality for decades post-expiry: evidence for increasing antivenom shelf life to aid in alleviating chronic shortages

IntroductionAntivenom is a lifesaving medicine for treating snakebite envenoming, yet there has been a crisis in antivenom supply for many decades. Despite this, substantial quantities of antivenom stocks expire before...

Study of heavy metal in sediment of The Klagison River, Sorong City

The Klagison River is one of the rivers located in the North Sorong District to the Sorong Manoi District. The flow of the Klagison River is used by the sand mining industry to dispose of liquid waste products from mining sites. Mining activities are in the middle of the Klagison River so that it can affect the quality of river water and experience a decrease in carrying capacity due to the high level of turbidity in river water caused by sedimentation. The purpose of this research is to provide knowledge about the content of metal elements in sediments by identifying the constituent elements of the Klagison River sediments, Sorong City, West Papua. Determination of the sampling point using the purposive sampling method and the sediment collection tool using the Ekman grab. The method of analyzing the constituent elements of the sediment uses the XRF (X-Ray Fluorescence) method. Based on the research results, there are various types of metal elements contained in the sediments of the Klagison River, namely the elements Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Rb, Sr, Zr and Re where the dominant concentration of metal elements from 5 observation stations is Fe&gt;Si&gt;K&gt;Cl&gt;Al&gt;Ca. At the 5 observation stations, the element Fe&gt;Si&gt;K&gt;Cl&gt;Al&gt;Ca was the highest compared to the other 4 observation stations. This is because station 5 is the mouth of the Klagison River so that it becomes a place for liquid waste deposits to coalesce.

Effectiveness of Using Chicken Eggshells as a Biocoagulant in Groundwater Treatment

The groundwater in Kota Bambu Selatan, West Jakarta, has high levels of turbidity and TDS. Therefore, it is necessary to be treated in order to comply with the regulations outlined in the Minister of Health of the Republic of Indonesia Number 2 of 2023 concerning Environmental Health standards. This study aims to investigate the effectiveness chicken eggshells as a biocoagulant for treating this groundwater. The techniques employed encompassed coagulation and flocculation, involving different coagulation G.td values (17,000, 34,000, 48,000, and 96,000) and a range of biocoagulant doses (100-500 mg/L). The outcomes of the treatment revealed that the utilization of chicken eggshells as a biocoagulant led to the removal of 47.14% of TDS and 97.17% of turbidity. The cost associated with implementing chicken eggshells as a biocoagulant amounted to IDR 230.70 per liter. In light of these findings, it can be deduced that chicken eggshells serve as an effective biocoagulant for reducing TDS and turbidity in the groundwater treatment.

Effects of storm runoff on the spatial-temporal variation and stratified water quality in Biliuhe Reservoir, a drinking water reservoir.

Stormflow runoff is an important non-point source of pollution in drinking water reservoirs. Storm runoff is usually very turbid and contains a high concentration of organic matter, therefore affecting water quality when it enters reservoirs. In order to investigate the impact of storm runoff on spatial-temporal variation and stratification of water quality during this rainstorm event, the inflow process of the storm runoff was studied through a combination of field investigation and simulation using the Delft3D-Flow model. Water samples were collected from Biliuhe Reservoir at four different periods: before storm runoff, storm runoff flood peak period, 1week after storm runoff, and 5weeks after storm runoff. The results showed that the input of storm runoff resulted in a significant increase in the nitrogen (N) and phosphorus (P) in the reservoir water, especially in the reservoir entrance. The concentrations of total nitrogen (TN) and total phosphorus (TP) gradually decreased after the flood peak period; however, the average concentrations of TN and TP in the entire reservoir remained higher than those before the storm runoff levels for an extended duration. The storm runoff will greatly contribute to the contamination of water quality in a reservoir, and the water quality cannot be quickly restored by self-purification in the short term. During the flood peak period, under the influence of density current, the electrical conductivity (EC) and turbidity increased significantly in the water depth of 10-15m, so that the reservoir water had obvious stratification between 10 and 15m. The form of pollutants in storm runoff was mostly in particle phosphorus. Total particulate phosphorus (TPP) concentration was 0.015 ± 0.011mg/L, accounting for 44.12% of total phosphorus (TP) concentration in storm runoff flood peak period. The process of a rainstorm caused runoff, which carried high levels of turbidity, particulate phosphorus, and organic matter. The storm runoff disrupts the stratification of the reservoir water. In terms of vertical distribution, the turbidity in the reservoir area increased to 73.75 NTU. Therefore, the occurrence of significant turbidity density flow in the reservoir is frequently accompanied by intense rainfall events. Gaining insights into the impact of storm runoff on the vertical distribution of reservoir turbidity can help managers in selecting an appropriate inlet height to mitigate high turbidity outflow.

Kelimpahan Dan Pola Pertumbuhan Kerang Bulu (Anadara antiquata) di Perairan Gunung Riting Kabupaten Belitung

Gunung Riting waters are located in Belitung Regency which has high water biota resource potential. One biota that has a high economic value is the feather shell (Anadara antiquata). Feather shells generally live in muddy waters in shallow waters with a high turbidity levels and are one of the important commodities that are very potentially developed. The purpose of this study was to find out the abundance, growth patterns and water quality in the waters of gunung which is the habitat of feather shells. The study was conducted from December 2019 to January 2020 at 3 sampling stations, sampling using the transect method. The results of the study obtained that the highest number of feather shells found in the waters of gunung riting obtained at Station 2 is 506 feather shells with an abundance of 33.73 individuals/m2, the pattern of growth of feather shells in the waters of gunung riting has an negative allometric growth pattern where long growth is more dominant than weight growth and the water quality obtained is able to support the growth and abundance of feather shells in the waters of gunung riting.

Spatial Patterns of Turbidity in Cartagena Bay, Colombia, Using Sentinel-2 Imagery

The Cartagena Bay in Colombia has vital economic and environmental importance, playing a fundamental role in both the port and tourism sectors. Unfortunately, the water quality of the bay is undergoing a deterioration process due to the significant influx of sediment from the artificial channel known as Canal del Dique. Although field campaigns are carried out semiannually with 12 monitoring stations to evaluate these impacts, understanding the spatial dynamics of suspended solids in the bay remains a challenge. This article presents a spatial analysis of water turbidity in the Cartagena Bay during the years 2018 to 2022, using Sentinel-2 images. To achieve this objective, an empirical algorithm was developed through the Monte Carlo simulation. The validation of the algorithm demonstrated an R-squared value of 0.83, with an RMSE of 2.72 and a MAPE of 24.93%. The results showed the seasonal variability, with higher turbidity levels during the rainy season, reaching up to 35 FNU, and lower turbidities during the dry season, dropping to 1 FNU. Furthermore, these findings indicated that the southern area of the bay presents the most significant turbidity variations. This research enhances our understanding of the bay’s turbidity dynamics and suggests an additional tool for its monitoring.

The Symbiodiniaceae and Bacterial Dynamic Composition of the Coral Echinopora gemmacea on Wuzhizhou Island

Coral’s susceptibility to bleaching is determined by the strength of the intricate mutual relationships among coral symbionts. However, there is limited knowledge about how the symbiotic members of the scleractinian coral Echinopora gemmacea respond to changes in their surrounding environmental conditions. In this study, we conducted a survey of seawater characteristics in the south and north zones of Wuzhizhou (WZZ) Island, measured symbiotic microalgal density and chlorophyll-a content in the corals, and performed metabarcoding of the Symbiodiniaceae and bacteria communities within coral tissue. Our findings demonstrated that the seawater in the north zone of WZZ Island had higher levels of turbidity, temperature, salinity, and dissolved oxygen content compared to the south zone. This indicated that the corals in the two zones were subjected to distinctive environmental conditions. Analysis of the Symbiodiniaceae composition revealed that Cladocopium sp. C1 and Cladocopium sp. C17 were the dominant species in the southern E. gemmacea, whereas Durusdinium sp. D1a and Cladocopium sp. C17 prevailed in the northern E. gemmacea. Consequently, symbiotic microalgal density and chlorophyll-a content were diminished in the northern E. gemmacea. Furthermore, correlation network analysis revealed the presence of intricate bacterial interactions that potentially mediate coral’s adaptation to environmental stress. This study provides insights into the differences in symbiotic members, including Symbiodiniaceae and bacteria, within E. gemmacea, and contributes to fundamental knowledge for coral conservation efforts.

Unveiling the Nexus the link between water quality index and phthalic acid ester concentrations in Tigris River

Monitoring water quality in an aquatic system is a crucial objective in pursuing sustainable development, despite the challenges posed by water scarcity and the impact of climate change. The objective of the present study was to examine the water quality of the Tigris River along its course from the point of entry into Baghdad city to its exit, particularly in the presence of Phthalic Acid Esters (PAEs). In both dry and wet seasons and from five sites of the river, nine environmental factors (Turbidity, Total dissolved solids, pH, dissolved oxygen, Chloride, nitrate, phosphate, sulfate, and Biological oxygen demand) and three PAEs (di-n-butyl phthalate (DBP), di-isononyl phthalate (DiNP), and di-2-ethyl hexyl phthalate (DEHP)) were investigated. Results revealed that the river has high levels of turbidity and Total dissolved solids, slightly alkaline, and well-aerated (dissolved oxygen >7 mg/L). Chloride, nitrate, phosphate, and sulfate values varied between seasons, as high values were recorded in the wet season. Biochemical oxygen demand levels were higher during the dry season. The highest value of total PAEs (2.20 μg/L) was observed during the dry season, and the lowest value was in the wet season (1.16 μg/L). The HQ results revealed that the river was ranked as a moderate risk area. However the water quality index and environmental risk index classified the water quality as a poor category, with a high-risk score in the study sites within Baghdad city. Therefore, despite the acceptable limit of PAEs in the river's water (<3 μg/L), its presence is an early alarm to withdraw attention to its environmental risk. These findings highlight the need for appropriate measures to control and remove pollutants to ensure a safe and healthy water supply in the Tigris River.

Biodiversity of hard coral (Scleractinia) and relation to environmental factors turbid waters in Spermonde Islands, South Sulawesi, Indonesia

Abstract. Parenden D, Jompa J, Rani C, Renema W, Tuhumena JR. 2023. Biodiversity of hard coral (Scleractinia) and relation to environmental factors turbid waters in Spermonde Island, South Sulawesi, Indonesia s. Biodiversitas 24: 4521-4529. Water turbidity has an impact on coral growth and the diversity of coral species in the waters. Calculation of coral cover, coral diversity and environmental parameters need to be done to determine the effect of environmental parameters on growth. This research was conducted in July 2020-February 2021 in the Spermonde Islands, South Sulawesi, Indonesia, which focused on the inner zone area with high turbidity levels. The research was conducted at four observation locations, namely Kayangan Island, Samalona Island, Gusung Tallang and Lae-Lae Island. Primary data in the form of coral cover using the Underwater Photo Transect method, diversity data using the quadrant transect method and environmental parameters measured in-situ and ex-situ. The results of this study showed (1) the percentage of coral cover at each research location was classified as poor because it was in the range of 3-15%, (2) coral diversity on Samalona Island was classified as high (H'=3.2) while on Kayangan Island, Laelae Island and Gusung Tallang was classified as medium with values ranging from 2.21-2.83; and (3) environmental parameters such as turbidity, Total Suspended Solid (TSS), Total Dissolved Solid (TDS), nitrate, and phosphate and based on the results of regression analysis has a negative effect on coral cover, while turbidity and Total Suspended Solid (TSS) parameters have a significant effect on coral cover (p&lt;0.05). These results have the potential to determine the composition of hard corals (Acropora sp.) in turbid areas and potentially serve as transplant fragments to mitigate coral damage.