Contamination of lead in fishes from Laguna de Bay was previously recorded to have the highest concentrations that may pose a hazard to human health. However, no previous study was conducted on its biomagnification. This research is the first exploratory study that examined lead biomagnification in a food web of the lake. Water quality, aquatic communities, trophic levels and lead concentrations were analyzed during the dry and wet seasons. Lead concentrations were analyzed using Atomic Absorption Spectrometry. Levels of lead in the water were 0.05 mg L-1 and 0.03 mg L-1 for dry and wet seasons, respectively. Lead concentrations increased in phytoplankton with 3.87 and 9.66 mg kg-1 lead during wet and dry season, respectively. Furthermore, lead levels increased in zooplankton with 2.92 and 14.31 mg kg-1 during wet and dry seasons, respectively. In fishes, the highest lead concentration in dry season was detected in Hypophthalmichthys nobilis with 0.38 mg kg-1 while the highest during wet season was observed in Oreochromis niloticus with 0.67 mg kg-1. Lead biomagnification was observed in this study in the following order: water < phytoplankton < zooplankton. However, this increasing trend did not continue up to fishes.
Keywords: Laguna de Bay, Lead Biomagnification, Contamination