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Asian Journal of Agriculture and Development (AJAD) - Call for papers!

Estrogenic disruption in male common carp (Cyprinus carpio Linnaeus) introduced to the east and west sites of Laguna De Bay

(Philippines), Doctor of Philosophy in Environmental Science (University of the Philippines Los Baños)

Dissertation Abstract:

Experiments were conducted to determine contamination of Laguna de Bay with estrogen disruptors and to examine their impact on introduced fish. Results revealed 17β-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 induced 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 hemosiderin pigments within MMCs was found to be greater in west bay fish compared with the reference group. In general, the results support and validate estrogenic pollution of the lake. Whether or not the reported E2 levels could elicit biologic effects that can compromise reproduction and population dynamics in fish and in higher vertebrates should be a subject of future research endeavors. Given the current weight of evidence on the adverse effects of estrogenic disruption, the implementation of measures that could prevent the discharge of these compounds in the lake watershed is recommended.