Preliminary comparative bioconcentration of heavy metals in aquatic organisms from selected ecosystems in Terengganu and Kelantan, Malaysia

Abstract

Heavy metal contamination in aquatic ecosystems poses a significant threat to environmental health and food safety, particularly in biodiverse regions such as Terengganu and Kelantan, Malaysia. This study assessed the concentrations of eleven (11) heavy metals - silver (Ag), aluminium (Al), arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), zinc (Zn) in eight (8) aquatic species from freshwater, brackish and marine habitats. The sampled organisms represented three major phyla: Chordata, Arthropoda, and Mollusca, collected from six study areas with different ecosystems. Samplings were conducted from March to April 2025. Heavy metals from the organisms' tissues were detected using Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES). Results revealed significant interspecies and spatial variations in metal accumulation (p< 0.05; One-Way ANOVA), primarily influenced by habitat type, feeding strategy, and ecological niche rather than body size. Bivalve species (Anadara pilula and Polymesoda expansa) and the mud crab (Scylla tranquebarica) from Setiu Wetlands exhibited the highest metal concentrations, particularly for Zn (43.8 ± 3.88, 37.12 ± 3.20 and 33.67 ± 2.85 mg/ kg, respectively) and Fe (19.9 ± 1.77, 75.92 ± 6.84 and 4.48 ± 0.39 mg/kg, respectively). In contrast, fish species of Diagramma pictum from Beting Lintang displayed significantly lower concentrations (Fe- 0.803 ± 0.07 mg/kg; and Zn- 0.816 ± 0.07 mg/kg). This study highlighted the importance of using benthic filter feeders for biomonitoring and provides a scientific basis for future research aimed at developing a bioaccumulation-based risk assessment model for sustainable aquatic resource management.