International Science Community Association International Research Journal of Environmental Sciences 15 1 2026 01 22 Comparative Spatiotemporal assessment and bioaccumulation strategies of Heavy Metals Across Protected, Pilgrimage and Urbanized Zones of the Pamba River Basin, Kerala, South India 14 22 EN Jaël AÏSSEKOU Carbegie Djidémi 1 Laboratory of Research in Biochemistry and Environmental Toxicology, Department of Biochemistry and Cell Biology, University of Abomey-Calavi, Benin Babatoundé KOUMOLOU Luc 2 Laboratory of Research in Biochemistry and Environmental Toxicology, Department of Biochemistry and Cell Biology, University of Abomey-Calavi, Benin Arouna YESSOUFOU 3 Laboratory of Applied Hydrology, National Water Institute, University of Abomey-Calavi, Benin Basile GOUETI 4 Laboratory of Biology and Molecular Typing in Microbiology, Department of Biochemistry and Cell Biology, University of Abomey-Calavi, Benin Elias ADANLOKONON 5 Laboratory of Research in Biochemistry and Environmental Toxicology, Department of Biochemistry and Cell Biology, University of Abomey-Calavi, Benin Bernadin ELEGBEDE Manou 6 Department of water and Sanitation, National Water Institute, University of Abomey-Calavi, Benin Haziz SINA 7 Laboratory of Biology and Molecular Typing in Microbiology, Department of Biochemistry and Cell Biology, University of Abomey-Calavi, Benin Ndubi Doryce 1 Department of Biological Sciences, Maasai Mara University, Kenya Osano Aloys 2 Department of Mathematics and Physical Sciences, Maasai Mara University, Kenya Abila Romulus 3 Department of Environmental Studies, Geography and Planning; Maasai Mara University, Kenya Vasudevan Vidhya 1 Department of Zoology, Catholicate College, Pathanamthita, Kerala, India Devy R. Aruna 2 Department of Zoology, St. Thomas College, Ranni, Kerala, India > Research Paper 2025 12 12 2026 01 22 The Pamba River is one of the major freshwater systems in Kerala, India. It plays a crucial ecological and socio-cultural role, particularly due to the annual Sabarimala pilgrimage that significantly increases human influence on the river basin. The present study provides a comparative spatiotemporal assessment of heavy metal concentrations across protected, pilgrimage, and urbanised zones of the Pamba River. It evaluates the bioaccumulation patterns in selected fish species from selected sites, also using water and sediment samples collected from Kakki Reservoir, Pamba, Chengannur and Punnamada regions. Heavy metals, including Al, Cr, Zn, Cd, and Pb, were quantified using standard analytical protocols. Results indicated substantially higher concentrations of Al and Cr in pilgrimage and urban regions, while protected upstream sites showed lower contamination. Sediments exhibited strong metal accumulation, especially for Al, Zn and Cr, reflecting combined geogenic and human-derived inputs. Bioaccumulation analysis in Anabas testudineus and Etroplussuratensis revealed elevated uptake of Al and Cr, indicating their sensitivity to fluctuating environmental metal loads. Seasonal comparison further showed increased metal concentrations during the pilgrimage period, highlighting the impact of large-scale human presence. Overall, the findings demonstrate progressive but spatially variable metal enrichment in the Pamba River system and emphasise the need for continuous monitoring, improved waste management during peak pilgrimage seasons and targeted conservation measures to safeguard this culturally and ecologically important river. Overall, the integrated dataset indicates that the Pamba River is undergoing uneven but progressive heavy metal enrichment driven by natural weathering, pilgrimage-associated disturbances and urban effluents in downstream sections. These findings highlight the need for sustained monitoring, improved waste management strategies during peak pilgrim seasons and targeted ecological restoration to preserve the river’s health and long-term sustainability. Copyright@ International Science Community Association