(BCF) of Lead (Pb) and Copper (Cu) in Mangrove Roots as an Indicator of Heavy Metal Accumulation

Abstract

Mangrove ecosystems play a crucial role in trapping, storing, and accumulating heavy metals from surrounding waters and sediments, making them important bioindicators for environmental monitoring and conservation in coastal areas. Heavy metals such as Lead (Pb) and Copper (Cu) can accumulate in mangrove tissues, and their distribution between plant organs and sediments can be evaluated through the Bioconcentration Factor (BCF). This study aimed to assess the BCF values of Pb and Cu in mangrove roots and sediments in the Mangrove Tahura Ngurah Rai, Bali. Sampling was conducted using a purposive random sampling method at several stations representing different mangrove zones. Sediment and root samples from four mangrove speciesRhizophoraapiculata, Rhizophora mucronata, Bruguiera gymnorrhiza, and Sonneratia albawere collected during low tide. Heavy metal concentrations were measured using Atomic Absorption Spectrophotometry (AAS). The BCF values were calculated as the ratio between the concentration of heavy metals in roots and those in sediments. The results showed that all species had BCF values < 1, classifying them as excluders. The highest Pb BCF value was 1.00 in Rhizophora mucronata and the highest Cu BCF value was 1.13 in Rhizophoraapiculata. Mean Pb BCF values were higher than Cu in all species, with Rhizophora apiculata (0.65±0.22) and Rhizophora mucronata (0.64±0.33) exhibiting greater accumulation potential than Bruguiera gymnorrhiza and Sonneratia alba. Variations in BCF values were influenced by root morphology, zonation, and ion uptake ability. These findings highlight the superior potential of Rhizophoraapiculata and Rhizophora mucronata for heavy metal uptake, underscoring their role in mangrove-based phytoremediation and coastal environmental conservation