Undergraduate Theses
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Item Geochemical association of Cr, Cu, Ni, and Pb in the sediments of Iloilo River estuaryArban, John Paul B. (Division of Physical Sciences and Mathematics, College of Arts and Sciences, University of the Philippines Visayas, 2005-04)The geochemical association of Cr, Cu, Ni, and Pb in the sediments of Iloilo River Estuary has been studied using a modified Tessier’s sequential extraction procedure. The results obtained show that most of the metals studied are mostly associated in the residual and organic matter fractions of the sediment samples (Cr: 66.26% - 74.36% in the residual,15.43% - 24.08% in the Fe-Mn oxide fraction, 8.14% - 12.71% in organic matter fraction, and 0.000% - 2.996% in the exchangeable/carbonate fraction; Cu: 39.30% - 46.73% in the residual, 12.00% - 52.18% in the organic fraction, 3.227% - 11.41% in the Fe-Mn fraction, and 0.000% - 17.43% in the exchangeable/carbonate fractions; Ni: 42.75% - 57.02% in the organic matter fraction, 24.93% - 39.33% in the residual, 5.814% - 14.15% in the Fe-Mn fraction, and 5.504% - 13.12% exchangeable/carbonate fraction; and Pb in sample AAA-21: 48.02% in the residual, 38.55% in the organic matter fraction, and 7.33% in the Fe-Mn fraction, and 6.078% in the exchangeable/carbonate fraction). The analysis of the total metal concentrations of the sediment samples taken from Iloilo River are found to be above the reported concentration of uncontaminated sediment except for Pb in sediment sample AAA-21 (Chromium: 102.1 ug/g - 150.5 pg/g; Copper: 62.56 pg/g - 111.7 pg/g; Nickel: 53.40 pg/g - 75.44 pg/g; and Lead in sample AAA-21: 22.21 pg/g). The study shows that about 50% of the total metal concentration in the sediment samples are bioavailable to the aquatic organisms.Item Fecundity and egg quality in two species of siganids (Siganus canaliculatus and Siganus fuscescens) from Lanuza Bay, Surigao del Sur, PhilippinesAnore, Gaguis Anito II T. (Division of Biological Sciences, College of Arts and Sciences, University of the Philippines Visayas, 2019-06)Siganus canaliculatus and Siganus fuscescens are two of the important yet highly exploited siganid aquatic resources in the Philippines. Only few studies for both species, especially for S. fuscescens, are available in the Philippine setting regarding its fecundity and egg quality. This study was conducted to provide information on the fecundity and egg quality of S. canaliculatus and S. fuscescens from Lanuza Bay, Surigao del Sur, Philippines. Fecundity was determined through gravimetric method in individual gonads. Fecundity range was determined to be 54,856 — 279,957 individual oocytes for S. canaliculatus and 7,397 — 563,722 for S. fuscescens. Fecundities of both species exhibited a weak to strong positive correlation to size, with higher correlation coefficient to standard length for S. canaliculatus and body weight for S. fuscescens. On the other hand, egg quality was determined through mean oocyte diameter, with diameters ranging from 176 — 426 ųm for S. canaliculatus and 171 — 500 pm for S. fuscescens. Mean oocyte diameters of both species exhibited weak positive correlation to size, but with a higher correlation coefficient on standard length. Regulating the capture of smaller-sized fishes and allowing them to grow would promote the increase in fecundity and egg quality of the species.