Bioaccumulation of Lead (Pb) and Microplastic Contamination in the Estuary of Kombal Bay, North Lombok, Indonesia Using Padina sp. as a Bioindicator

Abstract

The Kombal Bay estuary in North Lombok, Indonesia, shows increasing pollution from anthropogenic sources such as shipping and domestic waste. This study assesses lead (Pb) bioaccumulation and microplastic contamination using Padina sp. as a bioindicator. Water, sediment, and tissue samples from Padina sp. were used in the sampling process. The content of Pb was analyzed using Atomic Absorption Spectrophotometry (AAS), while the distribution of Pb in tissues was analyzed using Scanning Electron Microscopy (SEM). Microplastics were analyzed by examining their morphological characteristics, type, and color using an optical microscope (Olympus Inverted). The research results show that Padina sp. significantly accumulates Pb, while the Pb content in the water is still below the quality standard threshold. SEM analysis revealed a consistent distribution of Pb throughout all part of Padina sp. tissue. On the other hand, microplastic contamination in Kombal Bay showed abundances ranging from 19.5±14.71 to 25±14.54 particles/L in water, 9.25±8.54 to 10.75±9.53 particles/kg in sediment, and 10.25±13.28 to 10.5±10.28 particles/individual on Padina sp. The types of microplastics found include fragments, films, pellets, and fibers, with dominant color variations of yellow, blue, red, black, and green. This finding indicates that coastal ecosystems are experiencing multi-pollutant pollution stress, which could potentially harm aquatic organisms and human health. Therefore, mitigation measures for pollution and further research are needed regarding the long-term toxicological impacts of heavy metals and microplastics on marine biota.