UPV Theses and Dissertations
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Item Microbiological assessment and detection of potentially pathogenic bacteria on three areas along the Iloilo RiverCaballo, John Carlo P. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2011-04)The Iloilo River, which traverses the whole length of Iloilo City, serves as a water source for different human activities hence, subjecting it to a variety of pollutants. Microbial and physico-chemical parameters of the three areas along the Iloilo River (Carpenter’s Bridge, IBRD Bridge, and Dungon Creek) were assessed to in order to provide a quantifiable evaluation of the river’s water quality. The presence of Salmonella spp., Eschericia coli, Streptococcus spp. and Vibrio spp., was also determined. HPC counts indicate very-high to extremely-high levels of bacterial loading (5.31 x 105-l .60 x 106 CFU/lOOmL) among the three sampling areas. Total coliform levels indicated contamination of the river from outside sources, potentially from domestic sewage discharges and run-offs from nearby establishments. The FC: FS ratio suggests contamination mostly came from mixed origins, with the noted exception of Carpenter’s Bridge, which is dominated by human fecal contamination. Minimal variations in physico-chemical parameters were observed for all areas. Significant correlations were found among salinity (p=0.002) and temperature (p=0.042) with TC; between FS with dissolved oxygen (p=0.00), and between FC and temperature (p=0.005). Contamination of the river by organic and fecal matter from animal and human sources provided a suitable habitat for pathogenic bacteria. A considerable quantity of potentially pathogenic bacteria such as; E.coli, Salmonella spp., Streptococcus spp. and Vibrio spp., were isolated from each sampling area. Exposure to these pathogens in drinking and recreational waters poses health risks to local inhabitants and to any individual who would consume water from the riverItem Toxicity of Chemically Enhanced Water-Accommodated Fraction (CEWAF) of Petron bunker C oil on Asian Sea bass Lates calcarifer (Bloch) fingerlings at different salinity levelsBondoc, Christian Earvin D. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2011-03)Asian sea bass Lates calcarifer fingerlings were exposed to three CEWAF concentrations (0.3, 0.5 and 1.0%) at 28, 32 and 36%o and the mortality rate among the different treatments were compared. Dunnett t-test (a=0.05) showed that mortality in the CEWAF-exposed treatments differed significantly from that in the control, indicating that the toxicity of CEWAF caused the death of the fingerlings. The general trend of mortality was increasing with increased salinity although the results of Two-Way ANOVA (a=0.05) reveal that salinity did not influence the toxicity of CEWAF significantly. Further analysis with Fisher’s LSD test (a=0.05) showed that mortality only differed significantly between the 28%o and 36%o salinity groups. The differences between the salinity levels used in this experiment were too narrow to cause a significant difference in the interaction between CEWAF concentration and salinity. Sublethal effects of exposure to CEWAF observed in this study included aberrant swimming behavior, arching of the back, loss of buoyancy and loss of pigmentation.
