Coinfections of Aeromonas spp., Enterococcus faecalis, and Vibrio alginolyticus isolated from farmed Nile tilapia and African catfish in Egypt, with an emphasis on poor water quality

2021 ◽  
Vol 160 ◽  
pp. 105213
Author(s):  
Mohamed Abdelsalam ◽  
M.A.Zaki Ewiss ◽  
Hanan S. Khalefa ◽  
Mahmoud A. Mahmoud ◽  
Mamdouh Y. Elgendy ◽  
...  
1998 ◽  
Vol 37 (2) ◽  
pp. 145-152 ◽  
Author(s):  
A. E. Nienhüser ◽  
P. Braches

Refilling of the Kerspe-Talsperre reservoir after restoration of the dam caused severe problems in water quality and supply due to a long-lasting ice-cover period and minimal precipitation. Unusually short spring overturn, high algal mass in spring and certainly the overflooding of the sediment, which had not been removed, caused a tremendous oxygen deficit in early summer. The whole hypolimnion turned anoxic and even in the metalimnion oxygen declined to a minimum. Manganese and iron reached high concentrations. Despite the poor water quality, raw water was urgently needed for the water supply and was pumped from the epilimnion during the clear water phase and in July when algal biomass was low. In the middle of August holomixis was induced artificially in order to improve water quality. The decline in algal production during and after artificial mixing was probably caused by light limitation of the algae.


2021 ◽  
Vol 232 (8) ◽  
Author(s):  
Ali Chabuk ◽  
Zahraa Ali Hammood ◽  
Nadhir Al-Ansari ◽  
Salwan Ali Abed ◽  
Jan Laue

AbstractIraq currently undergoing the problem of water shortage, although Iraq has two Rivers (Euphrates and Tigris) pass throughout most of its areas, and they have represented a major source of water supply. In the current research, to evaluate the quality of the Euphrates river in Iraq based on the values of total dissolved salts (TDS), the TDS concentrations were collected from sixteen sections along the river in the three succeeding years (2011, 2012, and 2013). The evaluation of the river was done depending on the classification of (W.H.O. (World Health Organization). (2003). Total Dissolved Salts in Drinking-water: Background document for development of W.H.O. Guidelines for Drinking-water Quality. World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland). of rivers for drinking uses. Inverse Distance Weighting Technique (IDWT) as a tool in the GIS was employed to establish the maps of the river that using interpolation/prediction for the TDS concentrations to each selected year and the average values of TDS for these 3 years. Based on the five categories of rivers’ classification of the TDS concentrations according to the (W.H.O. (World Health Organization). (2003). Total Dissolved Salts in Drinking-water: Background document for development of W.H.O. Guidelines for Drinking-water Quality. World Health Organization, 20 Avenue Appia, 1211 Geneva 27, Switzerland), the Euphrates river was classified, and the maps of classification for the years 2011, 2012 and 2013 and the average values for 3 years were created. The average values for 3 years of TDS along the Euphrates river indicated that the sections from SC-1 to SC-4 as moderate-water-quality-Category-3, the sections from SC-5 to SC-10 as poor-water-quality-Category-4, while the sections between SC-11 to SC-16 as very poor-water-quality-Category-5. The interpolation maps showed that the Euphrates river in Iraq was ranged from moderate water quality (Category-3) to very poor water quality (Category-5).


2011 ◽  
Vol 101 (3) ◽  
pp. 448-453 ◽  
Author(s):  
Joshua Graff Zivin ◽  
Matthew Neidell ◽  
Wolfram Schlenker

We examine the impact of poor water quality on avoidance behavior by estimating the change in bottled water purchases in response to drinking water violations. Using data from a national grocery chain matched with water quality violations, we find an increase in bottled water sales of 22 percent from violations due to microorganisms and 17 percent from violations due to elements and chemicals. Back-of-the envelope calculations yield costs of avoidance behavior at roughly $60 million for all nationwide violations in 2005, which likely reflects a significant understatement of the total willingness to pay to eliminate violations.


2016 ◽  
Vol 38 (2) ◽  
pp. 119 ◽  
Author(s):  
Davi De Holanda Cavalcante ◽  
Francisco Roberto dos Santos Lima ◽  
Vanessa Tomaz Rebouças ◽  
Marcelo Vinícius do Carmo e Sá

The present work aimed at determining the effects of the association between the periphyton-based system with the bioflocs-based system in the intensive culture of juvenile Nile tilapia (1.56 ± 0.07 g; 72 fish m-3), on variables of water quality, growth performance and effluent quality after 10 weeks. The experiment was arranged in a 2 x 2 factorial randomized block design with four treatments and five repetitions each. The factors tested were the following: ‘underwater structure’ (absence and presence) and ‘adjustment of the C: N ratio of water’ (no and yes). The final fish body weight, specific growth rate and yield were higher (p < 0.05) in the C: N-adjusted tanks. The presence of submerged structures in the tanks had no significant influence on those same variables. It was concluded that the periphyton-based system is not indicated for intensive farming of Nile tilapia, in which there is a high allowance of artificial feed to fish. 


2015 ◽  
Vol 17 (2) ◽  
pp. 105-112
Author(s):  
Olaniyi Alaba Olopade ◽  
Iyabode Olusola Taiwo ◽  
Comfort Opeoluwa Oluwoleand ◽  
Justin Ayaegbunem Akankali

Abstract This study was conducted to assess the effect of water quality of the Ogun River on the haematological indices of the African catfish Clarias gariepinus. Samples of water and Clarias gariepinus were collected from Ogun River (Station I, Opeji and Station II, Lafenwa) to determine and compare effects of possible differences in water quality on haematological parameters of Clarias gariepinus. The results demonstrate that higher index values were recorded at station II than Station I for almost all the physicochemical parameters and only sulphate values from Stations I and II were statistically significant (P < 0.05).


2019 ◽  
Vol 210 ◽  
pp. 103-112 ◽  
Author(s):  
V. Colson ◽  
A. Mure ◽  
C. Valotaire ◽  
J.M. Le Calvez ◽  
L. Goardon ◽  
...  

2020 ◽  
Vol 53 (2C) ◽  
pp. 87-104
Author(s):  
Kaiwan Fatah

Studying groundwater quality in arid and semi-arid regions is essential significant because it is used as a foremost alternative source for various purposes (human and animal consumption, economic, agriculture and irrigation). Geographic Information System and Water Quality Index techniques were utilized for visualizing and evaluating the variations of groundwater quality in the studied area. Total twelve wells were sampled and twelve groundwater quality (chemical) parameters; pH, Total Alkalinity, Total Hardness (TH), Total Dissolved Solid (TDS), Electrical Conductivity (Ec), Potassium (K), Nitrate (NO3), Sulfate (SO4), Chloride (Cl), Calcium (Ca), Magnesium (Mg) and Sodium (Na) were analyzed in the laboratory. Inverse Distance Weighted technique was used as a useful tool to create and anticipate spatial variation maps of the chemical parameters. Predicting or anticipating other areas not measured, identifying them and making use of them in the future without examining samples. The results of this research showed that 8.3% of the studied wells have excellent groundwater quality, and almost sampling wells about 75% found in good groundwater quality, while findings of groundwater quality of 16.7% studied wells belong to poor water quality due to standards of Water Quality Index. Moreover, spatial analysis in term of groundwater quality map showed that Excellent groundwater quality was detected in well 3, very good groundwater potential was noticed in six studied wells (wells 2, 6, 8, 10, 11 and 12), and other sampling wells (wells 4 and 7) were observed as good groundwater quality, while poor water quality was observed in wells (well 1 and 5). Hence, spatial distribution maps showed that the almost groundwater quality in the area about 1046.82 km² (99.04%) are suitable for drinking purpose, whereas proximate 10.18 km² (0.96%) are observed as poor water quality and inappropriate for consumptions especially in the southern part of the area.


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