Lead Uptake of the Asian Clam (Corbicula fluminea), Nile Tilapia (Oreochromis niloticus) and its Parasite (Acanthogyrus sp.) in Yambo Lake, Laguna, Philippines

Abstract

The contamination of heavy metals in the aquatic environment poses a threat due to its persistence and potential accumulation in aquatic life forms. In order to detect such pollution, the use of organisms as bioindicators was explored. This study investigated the use of fish acanthocephalan parasites as bioindicator of lead (Pb) in a semi-pristine Yambo Lake in San Pablo, Laguna, Philippines. Lake water samples, wild Nile tilapias (Oreochromis niloticus), its acanthocephalan parasites (Acanthogyrus sp.), and Asian clams (Corbicula fluminea) were collected and subjected to Pb concentration detection through heavy metal analysis. Higher accumulated mean concentration levels of Pb is recorded in Acanthogyrus sp. (10.13 mg kg-1), followed by the fish host tissues: liver (6.19 mg kg-1), intestine (2.80 mg kg-1), and muscle (0.75 mg kg-1). An established bioindicator, C. fluminea, only accumulated an average of 0.16 mg kg-1 Pb in its soft tissues. The bioaccumulation capacity of Acanthogyrus sp. to the fish host and water samples were 35 times higher than the liver, 190 times the intestine and 211 times than the muscle. Furthermore, the accumulated Pb in the parasite was 3,015 times higher than C. fluminea in lake water. Among all samples analyzed, Acanthogyrus sp. showed the highest accumulation capacity. These findings provide useful information to the bio indicator potential of this parasite, and that local environment authorities can utilize its sensitivity to detect and monitor traces of heavy metals even in less polluted aquatic environments.