ABSTRACT

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The water quality of surface waters is degrading tremendously due to human interventions and development. Especially in the Philippines, water pollution has become a prominent problem in urbanized areas. Thus, this study aims to investigate the ecotoxicological effects of the Ibayo River in Balanga City, Bataan using water fleas (daphnia magna), a type of zooplankton living in freshwater areas. Daphnids are used as indicators in toxicity testing, and in assessing water quality. The survival rate of water fleas is utilized to examine the properties of the examined. As the water fleas were subjected to the river water samples and their dilutions for a week, results showed a high survival rate in all samples. It also exhibited no significant difference in the sample places Meanwhile, laboratory analysis revealed that there is an organic pollution as an excessive amount of biological oxygen demand (BOD) and lesser dissolved oxygen from the sample places were found. Analysis for chlorine and pH level indicates a n ormal quantity. Overall, there are chemicals in the Ibayo river that may kill aquatic organisms residing in it, but the long-term survival of these species is still questionable.

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