Author : Michelle Grace Valle Paraso

Summary : Experiment were conducted to determine contamination of Laguna de Bay with estrogen disruptors and to examine their impact on introduced fish. Results revealed 17ß-estradiol (E2) levels in water samples ranging from 0.29 ± 0.07 µg/L to 0.40 ± 0.16 µg/L. Caging experiments in the east and west bay of the lake vitellogenesis in adult male common carp (Cyprinus carpio Linnaeus) and mild to moderate cases of testicular lesions that are consistent with estrogenic effect. A significantly reduced hepatosomatic index (HSI) was noted in the east bay fish. The lake environment also stimulated the formation of melanomacrophage centers (MMCs) of bigger size and number. The preponderance of melanin and hemoderin pigment within MMCs was found to be greater in west bay fish compared to the reference group. In general, the results support and validate estrogenic pollution of the lake. Wether or nor the reported E2 levels could elicit biologic effects that can compromise reduction and population dynamics in fish and in higher vertebrates should be a subject of future research endeavors. Given the current weight of evidence of the adverse effects of estrogenic disruption, the implementation of measures that could prevent the discharge of these compounds in the lake watershed is recommended.