scholarly journals The Population of Mangrove Clam (Polymesoda expansa) in The Panikel Village, Segara Anakan, Cilacap

2020 ◽  
Vol 147 ◽  
pp. 02018
Author(s):  
Widianingsih Widianingsih ◽  
Ria Azizah Tri Nuraini ◽  
Ita Riniatsih ◽  
Retno Hartati ◽  
Sri Redjeki ◽  
...  

Mangrove clam Polymesoda expansa belonged to the family Corbiculidae. The clam itself is a semi-infauna that lives partially below the soft sediment around the roots of mangrove trees. The purpose of this research is to study the population P. expansa in Panikel Area, Segara Anakan, Cilacap. The size of the sampling site for this research was 10x10 m. Mangrove clam P. expansa was taken by handpicking. Sampling was conducted in April and June 2019. The water quality parameters were taken in-situ. According to the research result, the highest population of P. expansa in Panikel occurred in June amounting to 85 individuals. In the Panikel area, P. expansa has a positive correlation between the total weight and shell length not only in April but also in June. It can be concluded that the mangrove area in Panikel Village is suitable for supporting P. expamsa population.

2014 ◽  
Vol 2 (3) ◽  
Author(s):  
Wihelmina Dimara ◽  
Edwin D Ngangi ◽  
Lukas L.J.J Mondoringin

The objective of this research was to evaluate the suitability of several environment factors and water quality parameters for development of seaweed culture in Kampung Sakabu.  The research was conducted through observation at three stations while protection factor and bottom substrate of waters were observed visually. Water quality parameters including pH, salinity, current rate, temperature were measured in situ and the compared to Standard Water Quality Citeria by Bakosurtanal 1996.  Research results were divided into three suitability categories namely 1) very suitable, 2) suitable, and 3) less suitable.  In general, environmental condition and water quatily in Kampung Sakabu were categorized as suitable to very suitable. This results indicated that         waters of Kampung Sakabu was very potential for development of seaweed culture. Keywords:  Kampung Sakabu, seaweeds, area suitability, water quality


2020 ◽  
Vol 12 (10) ◽  
pp. 1586
Author(s):  
Leonardo F. Arias-Rodriguez ◽  
Zheng Duan ◽  
Rodrigo Sepúlveda ◽  
Sergio I. Martinez-Martinez ◽  
Markus Disse

Remote-sensing-based machine learning approaches for water quality parameters estimation, Secchi Disk Depth (SDD) and Turbidity, were developed for the Valle de Bravo reservoir in central Mexico. This waterbody is a multipurpose reservoir, which provides drinking water to the metropolitan area of Mexico City. To reveal the water quality status of inland waters in the last decade, evaluation of MERIS imagery is a substantial approach. This study incorporated in-situ collected measurements across the reservoir and remote sensing reflectance data from the Medium Resolution Imaging Spectrometer (MERIS). Machine learning approaches with varying complexities were tested, and the optimal model for SDD and Turbidity was determined. Cross-validation demonstrated that the satellite-based estimates are consistent with the in-situ measurements for both SDD and Turbidity, with R2 values of 0.81 to 0.86 and RMSE of 0.15 m and 0.95 nephelometric turbidity units (NTU). The best model was applied to time series of MERIS images to analyze the spatial and temporal variations of the reservoir’s water quality from 2002 to 2012. Derived analysis revealed yearly patterns caused by dry and rainy seasons and several disruptions were identified. The reservoir varied from trophic to intermittent hypertrophic status, while SDD ranged from 0–1.93 m and Turbidity up to 23.70 NTU. Results suggest the effects of drought events in the years 2006 and 2009 on water quality were correlated with water quality detriment. The water quality displayed slow recovery through 2011–2012. This study demonstrates the usefulness of satellite observations for supporting inland water quality monitoring and water management in this region.


2015 ◽  
Vol 21 ◽  
pp. 27-34 ◽  
Author(s):  
Md Lifat Rahi ◽  
Sarower E Mahfuj ◽  
Sk Shahinur Islam ◽  
S Saiful Islam ◽  
Wasim Sabbir

Context: Phytoplanktonic community structure in an aquatic body embodies the energy transfer through this phase and indicates the tropic status. Objectives: The present study was conducted to assess the phytoplankton abundance and species composition of Mouri River, Khulna, Bangladesh. Materials and Methods: Water samples were collected from six different stations once in a week for a period of 6 months (February- July) 2010. Results: In total 48 different species of 23 genus and 4 families were identified. Phytoplankton abundance varied from 805 to 1788 individuals/L in different stations. The highest abundance was observed for the family chlorophyceae that constituted 27-50.56% of the total phytoplankton biomass throughout the river. Highest number of phytoplankton species (22) was also recorded for the family chlorophyceae. The most diverse genus was Navicula (6). Some aspects of the water quality parameters were measured by regression analysis and significant correlations were also observed between water quality parameters and phytoplankton abundance. Water temperature, pH, DO, Free CO2, alkalinity, hardness, calcium and magnesium showed positive correlations with total phytoplankton abundance where as transparency, TDS, TSS, sulfate phosphate and nitrite showed negative correlations. Conclusion: In most of the cases, phytoplankton abundance and water quality parameters showed greater deviation from the optimum level. However, the results of the present experiment confirmed the polluted water of the river. DOI: http://dx.doi.org/10.3329/jbs.v21i0.22516 J. bio-sci. 21: 27-34, 2013


2020 ◽  
Vol 12 (11) ◽  
pp. 1745
Author(s):  
Michael Seidel ◽  
Christopher Hutengs ◽  
Felix Oertel ◽  
Daniel Schwefel ◽  
András Jung ◽  
...  

Freshwater lakes provide many important ecosystem functions and services to support biodiversity and human well-being. Proximal and remote sensing methods represent an efficient approach to derive water quality indicators such as optically active substances (OAS). Measurements of above-ground remote and in situ proximal sensors, however, are limited to observations of the uppermost water layer. We tested a hyperspectral imaging system, customized for underwater applications, with the aim to assess concentrations of chlorophyll a (CHLa) and colored dissolved organic matter (CDOM) in the water columns of four freshwater lakes with different trophic conditions in Central Germany. We established a measurement protocol that allowed consistent reflectance retrievals at multiple depths within the water column independent of ambient illumination conditions. Imaging information from the camera proved beneficial for an optimized extraction of spectral information since low signal areas in the sensor’s field of view, e.g., due to non-uniform illumination, and other interfering elements, could be removed from the measured reflectance signal for each layer. Predictive hyperspectral models, based on the 470 nm–850 nm reflectance signal, yielded estimates of both water quality parameters (R² = 0.94, RMSE = 8.9 µg L−1 for CHLa; R² = 0.75, RMSE = 0.22 m−1 for CDOM) that were more accurate than commonly applied waveband indices (R² = 0.83, RMSE = 13.2 µg L−1 for CHLa; R² = 0.66, RMSE = 0.25 m−1 for CDOM). Underwater hyperspectral imaging could thus facilitate future water monitoring efforts through the acquisition of consistent spectral reflectance measurements or derived water quality parameters along the water column, which has the potential to improve the link between above-surface proximal and remote sensing observations and in situ point-based water probe measurements for ground truthing or to resolve the vertical distribution of OAS.


2020 ◽  
Vol 8 (3) ◽  
pp. 172-185
Author(s):  
Juan G. Arango ◽  
Brandon K. Holzbauer-Schweitzer ◽  
Robert W. Nairn ◽  
Robert C. Knox

The focus of this study was to develop true reflectance surfaces in the visible portion of the electromagnetic spectrum from small unmanned aerial system (sUAS) images obtained over large bodies of water when no ground control points were available. The goal of the research was to produce true reflectance surfaces from which reflectance values could be extracted and used to estimate optical water quality parameters utilizing limited in-situ water quality analyses. Multispectral imagery was collected using a sUAS equipped with a multispectral sensor, capable of obtaining information in the blue (0.475 μm), green (0.560 μm), red (0.668 μm), red edge (0.717 μm), and near infrared (0.840 μm) portions of the electromagnetic spectrum. To develop a reliable and repeatable protocol, a five-step methodology was implemented: (i) image and water quality data collection, (ii) image processing, (iii) reflectance extraction, (iv) statistical interpolation, and (v) data validation. Results indicate that the created protocol generates geolocated and radiometrically corrected true reflectance surfaces from sUAS missions flown over large bodies of water. Subsequently, relationships between true reflectance values and in-situ water quality parameters were developed.


2020 ◽  
Author(s):  
Dainis Jakovels ◽  
Agris Brauns ◽  
Jevgenijs Filipovs ◽  
Tuuli Soomets

<p>Lakes and water reservoirs are important ecosystems providing such services as drinking water, recreation, support for biodiversity as well as regulation of carbon cycling and climate. There are about 117 million lakes worldwide and a high need for regular monitoring of their water quality. European Union Water Framework Directive (WFD) stipulates that member states shall establish a programme for monitoring the ecological status of all water bodies larger than 50 ha, in order to ensure future quality and quantity of inland waters. But only a fraction of lakes is included in in-situ monitoring networks due to limited resources. In Latvia, there are 2256 lakes larger than 1 ha covering 1.5% of Latvian territory, and approximately 300 lakes are larger than 50 ha, but only 180 are included in Inland water monitoring program, in addition, most of them are monitored once in three to six years. Besides, local municipalities are responsible for the management of lakes, and they are also interested in the assessment of ecological status and regular monitoring of these valuable assets. </p><p>Satellite data is a feasible way to monitor lakes over a large region with reasonable frequency and support the WFD status assessment process. There are several satellite-based sensors (eg. MERIS, MODIS, OLCI) available specially designed for monitoring of water quality parameters, however, they are limited only to use for large water bodies due to a coarse spatial resolution (250...1000 m/pix). Sentinel-2 MSI is a space-borne instrument providing 10...20 m/pix multispectral data on a regular basis (every 5 days at the equator and 2..3 days in Latvia), thus making it attractive for monitoring of inland water bodies, especially the small ones (<1 km<sup>2</sup>). </p><p>Development of Sentinel-2 satellite data-based service (SentiLake) for monitoring of Latvian lakes is being implemented within the ESA PECS for Latvia program. The pilot territory covers two regions in Latvia and includes more than 100 lakes larger than 50 ha. Automated workflow for selecting and processing of available Sentinel-2 data scenes for extracting of water quality parameters (chlorophyll-a and TSM concentrations) for each target water body has been developed. Latvia is a northern country with a frequently cloudy sky, therefore, optical remote sensing is challenging in or region. However, our results show that 1...4 low cloud cover Sentinel-2 data acquisitions per month could be expected due to high revisit frequency of Sentinel-2 satellites. Combination of C2X and C2RCC processors was chosen for the assessment of chl-a concentration showing the satisfactory performance - R<sup>2</sup> = 0,82 and RMSE = 21,2 µg/l. Chl-a assessment result is further converted and presented as a lake quality class. It is expected that SentiLake will provide supplementary data to limited in situ data for filling gaps and retrospective studies, as well as a visual tool for communication with the target audience.</p>


1993 ◽  
Vol 27 (3-4) ◽  
pp. 137-143 ◽  
Author(s):  
Pierre Payment ◽  
Eduardo Franco ◽  
Jack Siemiatycki

An 18-month prospective epidemiological study of gastrointestinal illnesses was conducted on 300 families consuming conventionally treated tap water and 300 consuming the same water after further treatment by reverse-osmosis. Drinking water met current bacteriological and physicochemical quality standards, but was found to be associated with a significant level of gastrointestinai illnesses: a reduction of 30% of the gastrointestinal illnesses was observed in the group consuming the filtered water. The presence or absence of total coliforms or fecal coliforms was not indicative of the health effects observed. The heterotrophic plate counts at 20°C in the distribution system were weakly associated with the duration of the symptoms when the data was analyzed by subregion. Several approaches to clustering of the family data to the nearest sampling site were attempted: no association could be demonstrated. Even if consumers of reverse-osmosis water experienced, on the average, less gastrointestinal illnesses, their illnesses were significantly associated with the number of bacteria growing at 35°C on medium R2A. The problems associated with the predictive value of the bacterial content of a water sample and in particular, the major differences between water quality at the tap and in the distribution system are presented. For example, standard procedures require analysis of the water after flushing the tap for several minutes: this is not however typical of the water that is consumed. Water that comes out of the tap has stagnated for long periods in household pipes and regrowth of bacterial contaminants can easily occur. The bacteria growing in this water might thus be responsible for some of the health effects observed in tap water.


2015 ◽  
Vol 6 (1) ◽  
pp. 59-67
Author(s):  
K Rakiba ◽  
Z Ferdoushi

Among different water quality parameters dissolved oxygen, transparency, pH, PO4-P and depth varied significantly among the sampling sites. The pH value in the present investigation remained a buffer condition (6.50- 7.90). Dissolved oxygen was ranges from 3.80 to 11.60 mg/l throughout the study periods. PO4-P concentration was observed highest (0.30 mg/l) in sampling site 2. On the basis of physical, chemical aspects sampling site 3 and sampling site 5 (situated in gosaipur and chandandoho) found in better condition in terms of limnological aspects. However, it could be concluded that Dhepa River will play important role in riverine fisheries and for further fisheries management.DOI: http://dx.doi.org/10.3329/jesnr.v6i1.22041 J. Environ. Sci. & Natural Resources, 6(1): 59-67 2013


2015 ◽  
Vol 7 (2) ◽  
pp. 319-348 ◽  
Author(s):  
B. Nechad ◽  
K. Ruddick ◽  
T. Schroeder ◽  
K. Oubelkheir ◽  
D. Blondeau-Patissier ◽  
...  

Abstract. The use of in situ measurements is essential in the validation and evaluation of the algorithms that provide coastal water quality data products from ocean colour satellite remote sensing. Over the past decade, various types of ocean colour algorithms have been developed to deal with the optical complexity of coastal waters. Yet there is a lack of a comprehensive intercomparison due to the availability of quality checked in situ databases. The CoastColour Round Robin (CCRR) project, funded by the European Space Agency (ESA), was designed to bring together three reference data sets using these to test algorithms and to assess their accuracy for retrieving water quality parameters. This paper provides a detailed description of these reference data sets, which include the Medium Resolution Imaging Spectrometer (MERIS) level 2 match-ups, in situ reflectance measurements, and synthetic data generated by a radiative transfer model (HydroLight). These data sets, representing mainly coastal waters, are available from doi:10.1594/PANGAEA.841950. The data sets mainly consist of 6484 marine reflectance (either multispectral or hyperspectral) associated with various geometrical (sensor viewing and solar angles) and sky conditions and water constituents: total suspended matter (TSM) and chlorophyll a (CHL) concentrations, and the absorption of coloured dissolved organic matter (CDOM). Inherent optical properties are also provided in the simulated data sets (5000 simulations) and from 3054 match-up locations. The distributions of reflectance at selected MERIS bands and band ratios, CHL and TSM as a function of reflectance, from the three data sets are compared. Match-up and in situ sites where deviations occur are identified. The distributions of the three reflectance data sets are also compared to the simulated and in situ reflectances used previously by the International Ocean Colour Coordinating Group (IOCCG, 2006) for algorithm testing, showing a clear extension of the CCRR data which covers more turbid waters.


2018 ◽  
Vol 6 (1) ◽  
Author(s):  
Karel Sumtaki ◽  
Ockstan J. J. Kalesaran ◽  
Cyska Lumenta

This study aimed to analyze the size of shell length, shell width and total weight of Pinctada margaritifera shells, and water quality parameters for the aquaculture development. Morphometric measurements include: shell length (PC), and shell width (LC), shell weight (BT). The results showed that PC size 8 - 11.99 cm, LC 8 - 9.99 cm and BT 80 - 99.99 gram dominate the Arakan waters  while PC size 6 - 9.99 cm, LC 6 - 7.99 cm and BT 60 - 79.99 gram dominate the Bahoi  waters. The results of water quality measurements in both locations are Bahoi waters, namely: 29-32oC, DO 7-8,5 mg/l, pH 7,8-7,9, salinity, 28-32 ppt, 4,5- 7 meters, 11 cm/sec. While in Arakan waters, the temperature was 30-30,8oC, DO 6,3-6,7 mg/l, pH 7,6-7,7 salinity 30 ppt, brightness 4-5 meter, current velocity 4,5 cm / second. Both locations were feasible for the development of pearl aquacultureKeywords: Morphometric, Pinctada margaritifera, Aquaculture


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