Water Turbidity Levels Research Articles

The effect of algal turbidity on larval performance and the ontogeny of digestive enzymes in the grey mullet (Mugil cephalus)

A study comprised of two trials determined the effects of water turbidity produced by live microalgae and inert clay particles on the larval rearing of grey mullet (Mugil cephalus). Trial 1 evaluated the effect of microalgae produced water turbidity on grey mullet larval performance and digestive tract (DT) enzyme ontogeny. Two microalgae (Nannochloropsis oculata and Isochrysis galbana) water turbidity levels (0.76 and 1.20 NTU, respectively) and a non-microalgae control (0.26 NTU) were investigated on 2 to 23 dph grey mullet larvae. The higher turbidity (1.2 NTU) larvae (5 dph) consumed markedly (P < .05) more rotifers than other treatment fish, independently of the microalgae type. There was no clear effect of the turbidity treatments on DT enzyme ontogeny. However, in all treatments lipase and alkaline proteases appeared to be modulated by the diet. Alkaline phosphatase activity was ca. 8 times higher and α-amylase activity increased 5.3 times in 79 dph fish compared to 40 dph individuals. The ratio of alkaline phosphatase and leucine-alanine aminopeptidase indicated gut maturation occurred around 61 dph. Trial 2 compared the most effective N.occulata produced turbidity level (1.2 NTU) with the identical water turbidity produced by inert clay on larval performance. M. cephalus larvae exposed to high algal turbidity demonstrated superior performance (P < .05), in terms of rotifer ingestion, dry weight gain and survival, compared to cohorts reared under the clay treatment and the lower microalgae produced turbidity. These findings suggested that water algal turbidity is not the dominant factor determining improved grey mullet larval performance.

Laboratory Efficacy and Disinfection by-Product Formation of a Coagulant/Disinfectant Tablet for Point-of-Use Water Treatment

Coagulant/disinfection products (CDPs) are a point-of-use (POU) water treatment technique that can improve microbial quality, reduce turbidity, and produce a free chlorine residual (FCR), serving as a potentially effective option for decentralized water treatment in a variety of contexts, including humanitarian emergencies. A novel CDP with a sodium dichloroisocyanurate-based disinfectant was evaluated with regard to its laboratory water treatment efficacy and generation of disinfection byproducts (DBPs). The CDP water treatment performance was assessed relative to bacteriological (E. coli) humanitarian water quality objectives, World Health Organization recommendations for evaluating POU water treatment options, and available DBP regulations and guidelines. At least 4 log10 E. coli reductions, for a “highly protective” status with regard to bacterial reductions, were attained in the tested conditions. Treated waters were consistently below 10 MPN/100 mL with regard to E. coli concentrations, with the majority of samples showing no detectable E. coli. For most conditions, target FCR values were not attained. Treated water turbidity levels were mostly between 5 NTU and 10 NTU. DBP levels were below the regulatory and health-based targets for both families of DBPs studied. This study has served to identify the performance envelopes of the CDP tested under challenging conditions.

Pola Penambahan Larutan Tawas untuk Penurunan Kekeruhan Air Sungai Martapura

Most of the Martapura River water in Tambak Anyar Village is used by the community for daily needs such as bathing and washing. Physically Martapura River water in Tambak Anyar Village does not meet the requirements seen in terms of turbidity to be used as a source of clean water. Water sources that do not meet the requirements must be processed before they are used. It is known that the turbidity of Martapura River water does not meet the standards of clean water according to the Minister of Health Regulation No. 416/MENKES/PER/IX/1990, the level of turbidity of the clean water is a maximum of 25 NTU. Turbidity in water can be caused by suspended and dissolved organic and inorganic substances such as mud, fine sand, plankton, and other microorganisms. This research is an experimental study. The aim of the study was to create a model for adding alum solution to Martapura river water with turbidity and pH parameters. The results of the study showed that the level of turbidity of water along the river Tambak Hanyar Martapura village ranged between 101-904 NTU and the water pH ranged between 6.31-6.60. The dosage of alum solution to decrease the turbidity level of river water in Tambak Hanyar Village up to 25 NTU ranged from 0.100 to 2.946 ml. Distance regression model with alum dosage and pH at 25 NTU turbidity is Alum Dose=0.122+0.455. (Distance). Doses in milliliters (ml) and distance in kilometers (km). It is suggested that the regression equation for decreasing the level of turbidity using the alum solution can be used according to the sampling point that has been done.

Distribution of fresh water snail intermediate host of trematode parasites in some fresh water bodies in Makurdi, Nigeria

The distribution of fresh water snail intermediate host of trematode parasites in an area is a bio-indicator of trematodiasis transmission in the locality. The distribution of some fresh water snail species in some fresh water bodies in Makurdi, Benue State, was carried out in four selected sites between June and September, 2016. It was aimed at determining the abundance of freshwater intermediate host of trematode parasites in the study-area. The scoop net method was employed with hand picking technique to collect snails, while morphological identification of snail was done using key in the Handbook of Danish Bilhaziasis Laboratory. Some physico-chemical parameters of water were also investigated at each site, 1,743 snails were collected. The distribution was: Melanoides tuberculate, 65.7%; Bulinus forskalii, 17.0%; Bulinus globosus,12.2%; Bulinus truncates, 4.5%; and Indoplanorbis exustus, 0.6 % respectively (x2 = 2422, df = 4, p<0.001). Snails distribution at various locations was: Ishwa Dam 71.4%; North Bank of River Benue 14.5%; Ityomu 7.9%; and Fete 6.1% (x2 = 1854, df = 12, p<0.001). The monthly distribution of the snail vectors also revealed a significant difference (x2 = 182, df = 9, p<0.001) in the snail species occurrence at the various sites. The population of the snails increased from June through September. This was accompanied by a decrease in the pH, biological oxygen demand (BOD) and dissolved oxygen (DO) in the water bodies, while temperature, turbidity and phosphate levels increased. This study has shown that there were significant intermediate hosts of Schistosoma haematobium, the causative agent of urinary schistosomiasis in the study area. Therefore, there is a need to undertake adequate snail control program and environmental sanitation awareness in the study area to curb the potential transmission of trematode parasitic diseases.Keywords: Fresh water; snail; intermediate host; trematode; physico-chemical parameters.

Remote sensing of water constituent concentrations using time series of in-situ hyperspectral measurements in the Wadden Sea

This study aimed to investigate the capability of the two-stream radiative transfer model 2SeaColor for the simultaneous retrieval of Chlorophyll-a (Chla), Suspended Particulate Matter (SPM) and Colored Dissolved Organic Matter (CDOM) concentrations from remote sensing measurements under various conditions (i.e., solar zenith angle values (SZAs) and water turbidity levels). For this evaluation, a time series of diurnal in-situ hyperspectral measurements of remote sensing reflectance (Rrs) concurrent with in-situ measured Chla and SPM concentrations between 2008 and 2010 by the NIOZ jetty station (the NJS), located in the Dutch part of the Wadden Sea, was used. Validation of the model retrievals against in-situ measurements showed an acceptable accuracy (Chla: R2 = 0.80 and RMSE = 2.98 [mg m−3]; SPM: R2 = 0.89 and RMSE = 2.53 [g m−3]) with good agreement between the temporal trends of measured and retrieved concentration values over multiple years. However, the model inversion results yielded less good estimates at SZA > 60° during winter. Furthermore, the effect of the tide on the variation of daily time series of Chla and SPM concentrations was analyzed. At the particular NJS location, the tidal effects on the concentrations of SPM and Chla were found to be small. The capability of the 2SeaColor model to retrieve reliable estimates, and the favorable location of the NJS, which is little influenced by tidal phase variations, contribute to a better understanding of the long-term variability of Chla and SPM concentrations. The results of this study may support the ongoing efforts on Sentinel-3 Ocean and Land Color Instrument (OLCI) calibration and validation at the Dutch Wadden Sea.

Prototype of Water Turbidity Monitoring System

Along with the increasing use of water by the community, the quality of water needs to be considered, especially for human consumption. Water quality is determined based on the value of turbidity of water. This project develops an Arduino Uno-based water turbidity monitoring system, which is aimed to measure water level and water turbidity levels. The turbidity sensor consists of a photodiode and infrared LED. Measurements of water turbidity using principles of light scattering in the water. The turbidity sensor to detect the intensity of light passing through the scattering of particles and the results of the analog signal voltage. The signal entering Arduino Uno of the ultrasonic sensor and the turbidity sensor will be processed. The measurement results is converted to NTU (Nephelometric Turbidity Units) and liter, then are shown on the LCD display 2x16. The turbidity measurement limits on this system are designed between 0 NTU to 40 NTU. This system can potentially help PDAM in monitoring water tanks and it is hoped that water quality monitoring system can be applied online.

Water quality of the Grijalva river in the Chiapas and Tabasco border

The objective was to characterize water quality for a section of the Grijalva River and its tributaries, for rainy and dry season in the border of the States of Chiapas and Tabasco. 23 physical, chemical, and microbiological parameters as well as contaminants were determined and compared with the Mexican norm NOM-127-SSA1-1994 which establishes water quality maximum permissible limits for use and human consumption and with the water quality classi cation scale proposed by the Comisión Nacional del Agua. Water quality of the Grijalva River in the studied section and tributaries, also locally named Almandros river, decreases as it descends to more populated areas of Tabasco. Water turbidity and high levels of coliforms and Escherichia are the main problems associated with the rivers of the studied area, even in water sources destined for human consumption. Other studied parameters have acceptable water quality mainly during the dry season, except for Mercury, which showed higher levels than the recommended by the norm in all sampling sites. The need to further study presence of Mercury in the Grijalva River basin is suggested.

Demonstration of 15-M 7.33-Gb/s 450-nm Underwater Wireless Optical Discrete Multitone Transmission Using Post Nonlinear Equalization

In this paper, we experimentally demonstrate an underwater wireless optical communication (UWOC) system using a 450-nm gallium nitride (GaN) laser and adaptive bit-power loading discrete multitone (DMT). To enhance the system capacity, a post nonlinear equalizer based on the simplified Volterra series is employed at the receiver to mitigate the nonlinear impairments of the UWOC system. By combining the adaptive bit-power loading with nonlinear equalization, 7.33-Gb/s DMT-modulated UWOC under 15-m tap water is achieved at a bit error rate below the 7% hard-decision forward error correction (FEC) limit 3.8 × 10–3. The electrical signal bandwidth is 1.25 GHz, which corresponds to an electrical spectrum efficiency of ∼6 bit/s/Hz. The capacity-distance product reaches 109.95 Gb/s-m in a single channel UWOC system with tap water. Compared with the linear equalization case, the system capacity at the FEC limit for 15-m underwater transmission is improved by ∼18% with the nonlinear equalization. Furthermore, the impact of turbidity on the performance of UWOC system is investigated by measuring the signal-to-noise ratio (SNR) under different suspension concentrations of Al(OH)3 and Mg(OH)2. The results show that significant SNR gains (>3 dB for transmission distance up to 11 m) can be obtained by the nonlinear equalization over a wide range of water turbidity levels representing “clear ocean,” “coastal ocean,” and “harbor water,” which demonstrates the robustness of the proposed scheme in various ocean environments.

The parasite community of the sharks Galeus melastomus, Etmopterus spinax and Centroscymnus coelolepis from the NW Mediterranean deep-sea in relation to feeding ecology and health condition of the host and environmental gradients and variables

The parasite communities of sharks have been largely neglected despite the ecological importance and vulnerability of this group of fishes. The main goal of the present study is to describe the parasite communities of three deep-dwelling shark species in the NW Mediterranean. A total of 120 specimens of Galeus melastomus, 11 Etmopterus spinax and 10 Centroscymnus coelolepis were captured at 400–2200m depth at two seasons and three localities off the mainland and insular slopes of the Balearic Sea. Environmental and fish biological, parasitological, dietary, enzymatic and histological data were obtained for each specimen, and the relationships among them tested. For G. melastomus, E. spinax and C. coelolepis a total of 15, two and eight parasite species were respectively recovered. The parasite community of G. melastomus is characterized by high abundance, richness and diversity, and the cestodes Ditrachybothridium macrocephalum and Grillotia adenoplusia dominate the infracommunities of juvenile and adult specimens, respectively. A differentiation of parasite communities, linked to a diet shift, has been observed between ontogenic stages of this species. E. spinax displays a depauperate parasite community, and that of C. coelolepis, described for the first time, shows moderate richness and diversity. Detailed parasite-prey relationships have been discussed and possible transmission pathways suggested for the three hosts. Parasites were mostly related to high water turbidity and O2 levels, which enhance zooplankton proliferation and could thus enhance parasite transmission. The nematodes Hysterothylacium aduncum and Proleptus obtusus were linked to high salinity levels, as already reported by previous studies, which are associated to high biomass and diversity of benthic and benthopelagic crustaceans. A decrease of acetylcholinesterase activity and lower hepatosomatic index, possibly linked to infection-related stress, have been observed. Lesions associated to encapsulated larvae of G. adenoplusia have been observed in the muscle of G. melastomus, especially in the tail region, which can be indicative of the hunting strategy of its final host and may compromise the escape response of G. melatomus thus facilitating parasite transmission.

Chromium Phytoremediation of Tannery Wastewater Using Ceratophyllum demersum L. (Coontail)

&lt;p&gt;Tanning industry produces liquid waste containing heavy metals, especially chromium – harmful for ecosystems and human health. Phytoremediation is a technique that utilizes the physiologicalpotential of plants to transform contaminants to be less or non-hazardous. The aim of the research is to determine the efficiency of &lt;em&gt;Ceratophyllum&lt;/em&gt;&lt;em&gt; &lt;/em&gt;&lt;em&gt;demersum&lt;/em&gt;&lt;em&gt; &lt;/em&gt;L. to remediate chrome in tannery wastewater. The research uses 84 strands of &lt;em&gt;C. demersum&lt;/em&gt;&lt;em&gt; &lt;/em&gt;compound leaves of 30 g wet weight. The treatments consist of the use of 7.74 mg/L, 11.30 mg/L, 17.00 mg/L and 23.73 mg/L concentrations of chromium and a control. The research is conducted using a static method. The design of the experimentis complete random design with 3 times of treatment in 14 days. The parameters observed are the efficiency of chromium phytoremediation, water turbidity, BOD, and total chlorophyll level of the leaves. The results show that the highest efficiency is gained at the concentration of 7.74 mg/L with 1.7% chromium, 17.3% water turbidity, and 46%BOD. Meanwhile, the highest efficiency of total chlorophyll level is 3.88 mg/L, gained at the concentration of 17.00 mg/L. In conclusion, &lt;em&gt;C. demersum &lt;/em&gt;is good to use as a &lt;em&gt;phytoremediator&lt;/em&gt; of tannery wastewater at the concentration of 7.74 mg/L&lt;a href="file:///D:/My%20Word/Jurnal/Dokumen%20Jurnal/Biosaintifika%202%20Akreditasi/12%20Agustus%202017/epa,%209%20mei,%20fiks.docx#_msocom_1"&gt;[V(F1]&lt;/a&gt; , subsequently, these results can be used as a basis for the consideration of the application implementation in the process of liquid waste reduction. &lt;/p&gt;

Mapping the spatio-temporal distribution of key vegetation cover properties in lowland river reaches, using digital photography.

The presence of vegetation in stream ecosystems is highly dynamic in both space and time. A digital photography technique is developed to map aquatic vegetation cover at species level, which has a very high spatial and a flexible temporal resolution. A digital single-lens reflex (DSLR) camera mounted on a handheld telescopic pole is used. The low-altitude (5m) orthogonal aerial images have a low spectral resolution (red-green-blue), high spatial resolution (∼1.9pixelscm-2, ∼1.3cm length) and flexible temporal resolution (monthly). The method is successfully applied in two lowland rivers to quantify four key properties of vegetated rivers: vegetation cover, patch size distribution, biomass and hydraulic resistance. The main advantages are that the method is (i) suitable for continuous and discontinuous vegetation covers, (ii) of very high spatial and flexible temporal resolution, (iii) relatively fast compared to conventional ground survey methods, (iv) non-destructive and (v) relatively cheap and easy to use, and (vi) the software is widely available and similar open source alternatives exist. The study area should be less than 10m wide, and the prevailing light conditions and water turbidity levels should be sufficient to look into the water. Further improvements of the image processing are expected in the automatic delineation and classification of the vegetation patches.

Detection of uneaten fish food pellets in underwater images for aquaculture

The waste of fish food has always been a serious problem in aquaculture. On one hand, the leftover fish food spawns a big economic loss in the industry because feedstuff accounts for a large proportion of the investment. On the other hand, the left over fish food may pollute the water and worsen the living environment of aquatic products. In this paper, we develop an adaptive thresholding method for detecting uneaten fish food in underwater images. To deal with non-uniform illumination in underwater environments, we focus on analyzing the local histogram of intensities in a mask for each pixel. The Expectation-maximization-guided Gaussian mixture is used to fit the histogram to figure out its type, and then an adaptive threshold is computed accordingly. At last the central pixel of the mask is compared with the threshold to generate the binary detection result. Experimental results show that the proposed method obtains desirable detection of leftover fish food in many underwater environments with different water turbidity levels and with different extent of unevenness of illumination. In the four test underwater environments, the lowest True Positive Rate of the proposed method is higher than 80%, and the highest rate reaches 95.9%. The False Positive Rates of the proposed method are no higher than 2.7%.

Real Time Monitoring System of Pollution Waste on Musi River Using Support Vector Machine (SVM) Method

Real-time Monitoring and early detection system which measures the quality standard of waste in Musi River, Palembang, Indonesia is a system for determining air and water pollution level. This system was designed in order to create an integrated monitoring system and provide real time information that can be read. It is designed to measure acidity and water turbidity polluted by industrial waste, as well as to show and provide conditional data integrated in one system. This system consists of inputting and processing the data, and giving output based on processed data. Turbidity, substances, and pH sensor is used as a detector that produce analog electrical direct current voltage (DC). Early detection system works by determining the value of the ammonia threshold, acidity, and turbidity level of water in Musi River. The results is then presented based on the level group pollution by the Support Vector Machine classification method.

A Multitiered Approach for Monitoring Water Quality

Development of effective means for remote and continuous monitoring of water quality represents an unmet need of significant importance. Cost effective, continuous assessment of water quality able to rapidly and sensitively signal the occurrence of noxious compounds is still a demanding, open issue. Since continuous monitoring of aquatic environment using biosensors is not sustainable, we propose a multitiered i.e. a two-step approach: the first one based on dynamics of selected aquatic species (e.g. fish) able to sensitively respond to occurrence of various types of contaminants for triggering the second step based on biosensors for specifically outline the actual perturbing cause.We address this challenge by advancing a new system based on the ICB proprietary solution for assessing the dynamics of fish, using a 3D array of ultrasound transducers, to relate fish behavior to the quality of their environment.Whereas fish behavior is already an established indicator of water quality, there are rather few systems able to effectively monitor and quantitatively assess fish dynamics. Most of such systems are based on image acquisition and processing, and are quite dependent on water turbidity or light level. The ICB proprietary fish behavior monitoring system - deploys a non-invasive technique for continuous monitoring of fish position not dependent on water transparency or lighting and uses a method for data analysis to provide real time information on the dynamics/behavior of (selected) fish species according to water quality and different stimuli.

Real Time Monitoring System of Pollution Waste on Musi River Using Support Vector Machine (SVM) Method

Real-time Monitoring and early detection system which measures the quality standard of waste in Musi River, Palembang, Indonesia is a system for determining air and water pollution level. This system was designed in order to create an integrated monitoring system and provide real time information that can be read. It is designed to measure acidity and water turbidity polluted by industrial waste, as well as to show and provide conditional data integrated in one system. This system consists of inputting and processing the data, and giving output based on processed data. Turbidity, substances, and pH sensor is used as a detector that produce analog electrical direct current voltage (DC). Early detection system works by determining the value of the ammonia threshold, acidity, and turbidity level of water in Musi River. The results is then presented based on the level group pollution by the Support Vector Machine classification method.

Temporal variation in methane emissions in a shallow lake at a southern mid latitude during high and low rainfall periods.

The global methane (CH4) emission of lakes is estimated at between 6 and 16% of total natural CH4 emissions. However, these values have a high uncertainty due to the wide variety of lakes with important differences in their morphological, biological, and physicochemical parameters and the relatively scarse data from southern mid-latitude lakes. For these reasons, we studied CH4 fluxes and CH4 dissolved in water in a typical shallow lake in the Pampean Wetland, Argentina, during four periods of consecutive years (April 2011-March 2015) preceded by different rainfall conditions. Other water physicochemical parameters were measured and meteorological data were reported. We identified three different states of the lake throughout the study as the result of the irregular alternation between high and low rainfall periods, with similar water temperature values but with important variations in dissolved oxygen, chemical oxygen demand, water turbidity, electric conductivity, and water level. As a consequence, marked seasonal and interannual variations occurred in CH4 dissolved in water and CH4 fluxes from the lake. These temporal variations were best reflected by water temperature and depth of the Secchi disk, as a water turbidity estimation, which had a significant double correlation with CH4 dissolved in water. The mean CH4 fluxes values were 0.22 and 4.09mg/m2/h for periods with low and high water turbidity, respectively. This work suggests that water temperature and turbidity measurements could serve as indicator parameters of the state of the lake and, therefore, of its behavior as either a CH4 source or sink.

Preliminary monitoring of faecal indicator organisms of surface water: A case study of Mvudi River, South Africa

Faecal contamination of water bodies is a known cause of high morbidity in developing countries. This study was carried out to assess the level of faecal contamination in Mvudi River used as a source of domestic water for people who live around it. Certified multimeters were used to measure pH, conductivity and turbidity while membrane filtration technique was employed to test for E. coli and total Enterococci in 18 water samples collected during sampling from January to March, 2014. The pH and conductivity values obtained varied between 7.30-7.88 and 10.47-15.94 mS/m respectively. Turbidity values were in the range of 17.57 and 429 NTU. E. colicounts were in the range of 950-11,533 cfu/100 mL while total Enterococci varied between 1,650-4,767 cfu/100 mL. The pH and EC data determined complied with the guideline values of the Department of Water Affairs and Forestry of South Africa (DWAF) and the World Health Organization (WHO) for domestic water use, but turbidity, E. coli and total Enterococci levels exceeded these guideline values. Mvudi River is microbiologically unfit and should not be used for drinking, domestic and recreational purposes without proper treatment. Keywords : Contamination, faecal indicator, organisms, surface, domestic water

Artificial Neural Network Approach for Predicting the Water Turbidity Level Using Optical Tomography

Water pollution can occur with a variety of reasons such as the change in water colour, the presence of harmful bacteria and toxic waste spills. This paper presents an application of an optical tomography system based on artificial neural network (ANN) to predict the turbidity level of water sample. The system made use of the independent component analysis algorithm to calculate the K value, which indicates the attenuation value of the water turbidity level. The K value then is utilized by ANN to estimate the turbidity level. The optical tomography system can be used to evaluate the water turbidity level in the pipeline without disturbing the flow process. Evaluation of the mean square error (MSE), sum square error (SSE) and regression analysis (R) also enabled us to determine the network performance which demonstrated that the neural network is effective in inspecting the water turbidity level. The best neurone structure is revealed when two hidden layers with 20 and 10 neurones in the first and the second layer, respectively, are used. The training result shows $${9.7147 \times 10^{-7}}$$ for MSE, 0.1432 for SSE and 0.99911 for regression. For the testing part, the result for the neurone structure is $${8.1473 \times 10^{-5}}$$ for MSE, 0.7509 for SSE and 0.98525 for regression. The results revealed that the performance of ANN demonstrated a good prediction capability when the turbidity level changed. Thus, an optical tomography system with ANN proved to be an efficient tool to classify the water quality level and is beneficial to the water industry.

Fecal Contamination in the Surface Waters of a Rural- and an Urban-Source Watershed.

Surface waters are commonly used as source water for drinking water and irrigation. Knowledge of sources of fecal pollution in source watersheds benefits the design of effective source water protection plans. This study analyzed the relationships between enteric pathogens ( O157:H7, spp., and spp. [, and ]), water quality (turbidity, temperature, and ), and human and ruminant-cow and mitochondrial DNA (mtDNA)-based fecal source tracking (FST) markers in two source watersheds. Water samples ( = 329) were collected at 10 sites (five in each watershed) over 18 mo. The human marker (HF183) occurred in 9 to 10% of the water samples at nine sampling sites; while a forested site in the urban watershed tested negative. Ruminant-cow markers (BacR and CowM2) only appeared in the rural watershed (6%). The mtDNA markers (HcytB and AcytB) showed the same pattern but were less sensitive due to lower fecal concentrations. Higher prevalences ( < 0.05) of spp. (41 vs. 16% for the rural and urban watershed, respectively) and O157:H7 (12 vs. 3%) were observed in the rural watershed, while spp. levels were comparable (23-28%). Densities of ≥100 colony-forming units (CFU) 100 mL increased the odds ( < 0.05) of detecting the enteric bacterial pathogens. The water turbidity levels (nephelometric turbidity units [NTU] ≥ 1.0) similarly predicted ( < 0.05) pathogen presence. Storm events increased ( < 0.01) pathogen and fecal marker concentrations in the waterways. The employment of multiple FST methods suggested failing onsite wastewater systems contribute to human fecal pollution in both watersheds.

Hydrodynamic and Sediment Modelling within a Macro Tidal Estuary: Port Curtis Estuary, Australia

An understanding of sediment transport processes and resultant concentration dynamics in estuaries is of great importance to engineering design awareness and the management of these environments. Predictive modelling approaches provide an opportunity to investigate and address potential system responses to nominated events, changes, or conditions of interest, often on high temporal and spatial resolution scales. In this study, a three-dimensional hydrodynamic model and wave model were validated and applied to generate forcing conditions for input into a sediment transport model for the period 7 May 2010–30 October 2010 within a macro tidal estuary, Port Curtis estuary (Australia). The hydrodynamic model was verified against surface and near-bottom current measurements. The model accurately reproduced the variations of surface and near-bottom currents at both a mid-estuary and upper-estuary location. Sediment transport model predictions were performed under varying meteorological conditions and tidal forcing over a 180-day period and were validated against turbidity data collected at six stations within Port Curtis estuary. The sediment transport model was able to predict both the magnitudes of the turbidity levels and the modulation induced by the neap and spring tides and wind-wave variations. The model-predicted (converted) turbidity levels compared favourably with the measured surface water turbidity levels at all six stations. The study results have useful practical application for Port Curtis estuary, including providing predictive capabilities to support the selection of locations for monitoring/compliance sites.