Heavy metal pollutants and their spatial distribution in surface sediments from Thondi coast, Palk Bay, South India

Abstract

Background The concentration of heavy metals and their spatial distribution in surface sediments collected from the Thondi coast, Palk Bay, South India were analysed in this study. The sediment grain size, pH, EC, and major elements (Fe, and Al), heavy metal concentrations (Mn, Cr, Zn, Cd, Ni, Cu, and Pb) were determined and the values for the geoaccumulation index (Igeo), enrichment factor (EF), potential contamination index (Cp), potential ecological risk index (RI), contamination factor (CF), modified contamination degree (mCd), degree of contamination (Cd), and potential contamination factors (Cp) were calculated based on their background values to determine the pollution level of the study area. Multivariate analysis such as Pearson’s correlation coefficient, principal component analysis/factor analysis (PCA/FA), cluster analysis, and regression analysis are a versatile method for identifying heavy metal sources and determining the relationship between pollutants in marine sediment. Results The pollution indices, namely EF, CF, Cd, mCd, CP, RI, and Igeo, revealed that the heavy metal contamination was due to Cd, while a moderate level of contamination was caused by Cu, Zn, Pb, and Cr. The principal component analysis and correlation matrix analysis showed a strong positive loading for Cd due to its high level of contamination in the study area. Anthropogenic inputs such as municipal wastewater, domestic sewage discharge, fishing harbour activities, and industrial and aquaculture wastes led to the increased Cd concentration in the study area. Moreover, the pollution load index revealed that the sediments were polluted by heavy metals. Conclusion The findings of this study revealed that the increased concentration of heavy metals in the study area increases the toxicity in the marine environment, thus affecting the ecosystem.

Sources, spatial distribution, and abundance of marine debris on Thondi coast, Palk Bay, Southeast coast of India

“…The region generally receives rainfall from southwest and northeast monsoons. The seawater is nutrientrich and turbid, with an average depth of 1-2 m. Because of the low wave action, the sediments are muddy [45]. Except for the ones carried out in the sense of this report, there are no formal beach cleanups on the Thondi coast.…”

“…The research area is rich in economically valuable marine resources and socio-economically beneficial activities like agriculture, aquaculture, and fishing. This area receives a lot of untreated waste from agricultural land (75%), built-up land (5%), wastelands (7%), and water bodies (13%) [45].…”

“…Globally many researchers apply CCI for assessing the cleanliness of coastal regions [13,[20][21][22][23][24][25][26][27][28][29][30][31][32]. Several past studies were focused on the distribution of heavy metals and pollution status of marine sediments (near the coast and shelf ) in various regions in the Bay of Bengal, India [33][34][35][36][37][38][39][40][41][42][43][44][45]. The objective of this study is (i) to identify the sources of marine debris; (ii) to determine the spatial distribution, abundance, and Clean-Coast Index (CCI) of marine debris of marine debris, and (iii) to elucidate the health status of Thondi coast, Palk Bay, Southeast coast of India.…”

Pre-to-post COVID-19 lockdown and their environmental impacts on Ghoghla beach and Somnath beach, India

“…There were no significant differences observed in the amount of clay, sand and silt at Ghoghla while drastic changes were observed in the above parameters in Somnath beaches, which is due to the siltation, and mixing of wastewater discharges to the open sea during post-lockdown regimes. Aeolian sedimentation, sewage discharges, deep-sea mining, etc., have resulted in the augmentation of metals into the water bodies (Naser 2013 ; Suresh et al 2015 ; Perumal et al 2021 ). All the heavy metals during the pre-lockdown period were high in all transects; however, the lockdown has favored the significant restoration of the natural environment of Ghoghla and Somnath beaches.…”

Sources, spatial distribution and abundance of marine debris on Thondi coast, Palk Bay, Southeast coast of India

“…[17] was developed and is suggested as a new tool for determining coast cleanliness. Many researchers were studied CCI using in worldwide regions in Mkomani beach [18], Kenya; in Cyprus [19]; in the Red Sea, Eritrea [20]; in Qatar [21]; in Dungonab and Mukkawar Island, Sudan, Red Sea [22]; in Asparuhovo Beach, Varna, Bulgaria [23]; in Beach off southwestern Luzon, Philippines [24]; in Pelagos sanctuary (The Ligurian Sea -NW Mediterranean Sea [25]; in Beaches of Arraial do Cabo, RJ, Brazil [26]; in Eastern Mediterranean [27]; in Salvador, Brazil [28]; in North-western Adriatic beaches [10]; in Slovenia [30]; and in Israeli coast [17]. The objective of this study is to identify the sources, spatial distribution, and abundance of marine debris along the Thondi coast, Palk Bay, Southeast coast of India, and to explore possible sources of marine debris, so as to come up with the preferences for enhanced future marine debris management in India.…”