Vol.:(0123456789) 1 3 Journal of Coastal Conservation (2022) 26:35 https://doi.org/10.1007/s11852-022-00881-4 Spatial distribution and enrichment of metals in surface sediments from diferent coastal landforms at southernmost Indian subcontinent Sajimol Sundar 1  · Priyadarsi D. Roy 2  · Lakshumanan Chokkalingam 1 Received: 23 December 2020 / Revised: 21 June 2022 / Accepted: 22 June 2022 © The Author(s), under exclusive licence to Springer Nature B.V. 2022 Abstract Cumulative urban and industrial activities have triggered remarkable modifcations in the land use and landcover of south- ernmost Indian subcontinent. This study presents spatial distributions and enrichments of eighteen major and trace elements in sediments of the foredune (D) and beachface (B) landforms present along the coastal stretch of Kanyakumari with respect to the continental crust to evaluate the possible geogenic and anthropogenic infuences. Ti (D: 76,842 mg/kg; B: 57,053 mg/ kg) is the most abundant among the elements and Cd (D: 4 mg/kg; B: 4 mg/kg) is the least abundant one. Extremely high (by enrichment factor) and very high (by contamination factor) enrichments of Ti, Cd, Mo, Th, and Zr refect the infuences of heavy minerals such as ilmenite, monazite, zircon, garnet, and rutile, and the Igeo values mirror their variable abundances across the sampling sites. Cd enrichment, in few sites, could be due to the sewage from fshing harbors. This baseline data of elemental concentrations (some potentially toxic metals) from a scarcely studied part of India are useful for the short- and long-term monitoring of growing anthropogenic activities related to the tourism and industry. Keywords Metal enrichment · Foredune · Beachface · Environmental Index · Kanyakumari Introduction Coastal sediments are a composite of diferent components of the marine ecosystem (Scavia et al. 2002; Cowell et al. 2003a, b; Lotze et al. 2006; Labuz 2015; Bigus et al. 2016). Their heavy metal compositions are associated with weath- ering of rocks, efuents from industries, solid wastes, and the animal and human excrements (Forstner and Wittmann 1981; Antonio and Ricardo 2003; Carman et al. 2007). The industrial and urban activities have dominated in recent decades, and all of them disrupted the geochemical cycle of natural elements (e.g., Meybeck 2003; Magesh et al. 2013; Mahu et al. 2015; Kasilingam et al. 2016). Enhance- ment in industrial activities and the population growth have also generated massive amounts of solid waste containing various metals, and most of them are discharged/disposed into the coastal ecosystem (Beiras et al. 2003; Milenkovic et al. 2005; Magesh et al. 2011; Krishnakumar et al. 2015). Some industries directly discharge efuents into the aquatic environments and the currents facilitate their transportation along the coast (e.g., Nergis et al. 2012). Mining activity is one of the large sources of metal. Some of these metals are potentially harmful at larger quantities (e.g., Hg, Pb, and Cd) and others are important nutrients (e.g., Fe, Mn, Co, Cu, and Zn) at low doses (Morton and Blackmore 2001; Nagajyoti et al. 2010). These heavy metals play important roles in biogeochemical processes, and their bioaccumula- tion signifcantly impact the ecosystem (Sajwan et al. 2008). Geochemical studies of metals in surface sediments along the coast with respect to the background values have contrib- uted to the growing awareness of pollution and the impact of heavy metals on the coastal ecosystem (e.g., Muller 1969; Balachandran et al. 2003; Wilson et al. 2008; Zahra et al. 2014). Most metals enter the ocean as suspended sediments and hence their concentrations are related to mineralogy (e.g., Li et al. 2000; Gaur et al. 2005; Singh et al. 2005; Jain et al. 2007; Aa et al. 2016). The abundance and distribu- tion of some heavy metals are also infuenced by the nature * Sajimol Sundar shamisaji17@gmail.com * Priyadarsi D. Roy roy@geologia.unam.mx 1 Department of Remote Sensing, Bharathidasan University, Tiruchirappalli 620023, India 2 Instituto de Geología, Universidad Nacional Autónoma de México (UNAM), Ciudad Universitaria, Coyoacan, C.P. 04510 Ciudad de Mexico, Mexico