Ecological risk assessment of heavy metals in varied matrices of coastal environment of Maharashtra, India, and their effects on forked venus clam, Gafrarium divaricatum (Gmelin, 1791)

Abstract

The spatial and seasonal variation of heavy metal contamination was assessed in the seawater, sediments, and clam samples collected from Ratnagiri, Bandra, and Aksa Beach, along Maharashtra Coast, India, during the different seasons. The concentrations of eleven heavy metals were analyzed using inductively coupled plasma-atomic emission spectroscopy (ICP-AES), and the metal concentrations were found in the order sediment > clam > seawater. Various pollution indices indicated that Cd and As mainly contributed to ecological risks, and Bandra was the most contaminated site. Bioaccumulation studies in intertidal clam, Gafrarium divaricatum (Gmelin, 1791), showed that most heavy metals exceeded permissible limits except Cu and Zn. Histopathological examination of the clam tissues revealed hemocyte infiltration, damage in cilia and lamellae of the gills, tubular atrophy, and necrosis in the digestive glands. The findings of this research highlight the potential of G. divaricatum as a reliable bioindicator species for biomonitoring and sustainable management of coastal ecosystems.