Heavy Metal Analysis and Histopathology of Gills of Nile Tilapia (Oreochromis niloticus) in Selected Areas of Candaba Swamp Pampanga

摘要

Aquatic ecosystem is now greatly dominated with various heavy metals as harmful chemical pollutants. Different organisms are mainly affected to this environmental problem due to ceaseless discharge of pollutants in their natural habitat. In this study the Nile tilapia (Oreochromis niloticus) that were collected from different stations at Candaba, Swamp, Pampanga were subjected to heavy metal analysis for the presence and level of Lead, Cadmium and Mercury in their gills. Histopathology was also done to determine histological damages in gills. Using Shimadzu Atomic Absorptions Spectrophotometry the study revealed that there is Cadmium toxicity in all stations in which station 1 and 3 are beyond the method detection limit (MDL) which is 0.02 mg/kg, whereas Lead toxicity which is beyond MDL (0.01 mg/kg) is also detected in Station 1 and 2. The level of mercury from the gill samples are also beyond the MDL (0.01 mg/kg) in stations 1 and 3 but mercury is not detected in station 2, this was carried out using DMA- Mercury Analyzer. Additionally, the result in histopathological manifestations in the gills of Nile Tilapia were revealed to have a shortening of secondary lamellae, lamellar fusion, hyperplasia, epithelial lifting, epithelial desquamation, cell mass damage, epithelial necrosis, epithelial degeneration, edema, proliferation of mucous cells, blood vessels dilation. The study provides an informative knowledge with regards to the status of contaminations of chemical pollutants in the aquatic ecosystem.