Sajimol Sundar

The coastal stretch of Kanyakumari district in Tamil Nadu, India is enriched with a variety of heavy minerals. The present study deals with the textural analysis, mineralogy and geochemistry of this placer deposits. Granulometric studies carried out on the study area shows that sands of all the sectors fall in medium and fine grade sand fraction with
moderately well sorted to moderately sorted nature. The moderate winnowing action results in the mixing of coarse and fine sediments in the coast. Linear Discriminative Function reveals all the samples fall in Shallow agitated Beach deposits and deposited by rolling, Bottom suspension and rolling mechanism. The sediments are formed under low energy level and results the deposition is mainly of fine to medium sediments. According to heavy mineral distribution, heavy minerals are mostly concentrated in both the eastern and western sector of the study area. The Isodynamic -Magnetic separator method also state the same result, it reveals that Ilmenite dominated in this study area and it is followed by the concentration of garnet. XRF data shows the presence of major oxides like TiO2 and Fe2O3 in the sample.Weathering mechanism of Ilmenite shows that they come under ferrian ilmenite.

Ocean zoning through marine spatial planning (MSP) is an important component of the blue economy and has become an essential step towards realizing ecosystembased sea-use management. The concept was primarily initiated by the need to create marine protected areas, particularly in the European countries. An even more recent concern has focused on the need to conserve nature, especially ecologically and biologically sensitive areas in the context of multi-use planning of ocean space. To understand the value of MSP in India, a framework was created as part of the Indo-Norway International Ocean Management and Research Initiative. This study provides a framework for MSP in India for sustainable development in an ecologically sensitive area, namely the Lakshadweep group of islands on the west coast of the country. The findings of this study may serve as a reference for better management of maritime regions under various spatial jurisdictions.

The coastal area is a dynamic and fragile environment which is very essential for many purposes such as resident, recreation, tourism, fisheries, agriculture, etc. Agriculture and fishing are the major source of developmental activities done by the local community in the coastal region. Therefore, coastal instability will directly affect the socio-economic conditions of the people residing nearby the coastline. This coastal instability will occur by both natural (Sea level rise, erosion and accretion) as well as anthropogenic factors (recreational activities, developmental activities and the construction of protection structures). This change in coastline will create a socio-economic impact to the local community. This study examines the changes in shoreline that occurred during the past two decades (2000 to 2020) along the Kanyakumari region in the southern tip of India. The results indicate a major retreat with some sea-ward movement due to sediment accumulation. Even though, the shoreline appears to be naturally dynamic due to long shore currents and beach morphology, the sediment movement due to external anthropogenic pressure exhibited a direct impact over the shoreline. A large part of the shoreline experienced erosion during the study period mostly due to construction of protective structures such as groins, jetties and sea walls. Major erosions were observed over the regions nearby harbors. Compared with the east coast region, the western part experiences more erosion which may be due to high energy waves. Coastal dunes in the Rajakkamangalam sector especially in locations Chothavilai, Sanguthurai, Periyakadu and Rajakkamangalam acts as a barrier against wind and waves keeping the inland areas safe from coastal hazards. More number of jetties and breakwaters were constructed during the past decade which eventually induces erosion in the one side and deposition on the other. Coastal villages such as Poothurai, Thengapattinam, Melmidalam, Colachel, Manavalakurichi and Kovalam experiences higher rate of erosion. This increased erosion will leads to the destruction of coastal properties and reduced fish catches which will deploy the economic growth of the region. It is also noted that, the coastal stretches should have been planned and monitored better through continuous observation of sea level rises and other potential environmental hazards. Hence, there is a need to develop proper interventions for sustainable coastal resource utilization.

During the last few decades, contamination of air, water and soil has become the talk of the era due to high anthropogenic influence especially in the metropolitan cities. Taking this in mind, this study is taken place to identify the influence of anthropogenic activity by assessing pollution of selected heavy metals in an urbanized environment. Concentrations of five heavy metals (Cd, Pb, Zn, Cr, and Cu) in 155 urban soil samples collected from an area covering ca.595 km 2 across the Greater Chennai Region (GCR) at the coast of Bay

During the last few decades, contamination of air, water and soil has become the talk of the era due to high anthropogenic influence especially in the metropolitan cities. Taking this in mind, this study is taken place to identify the influence of anthropogenic activity by assessing pollution of selected heavy metals in an urbanized environment. Concentrations of five heavy metals (Cd, Pb, Zn, Cr, and Cu) in 155 urban soil samples collected from an area covering ca.595 km 2 across the Greater Chennai Region (GCR) at the coast of Bay

Cumulative urban and industrial activities have triggered remarkable modifications in the land use and landcover of southernmost 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 influences. 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 reflect the influences 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 fishing 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.

Beach sediments of Kanyakumari at the southernmost India were evaluated for metals and trace elements and to assess their possible impact on coastal ecosystems. Positive correlations (except for Cd and Sr) between them indicated metamorphic lithologies and heavy mineral deposits as possible sources. Significant-extremely high enrichment and very high contamination of Th, Zr, Mo, Ti and U reflected the presence of different heavy minerals. The geo-accumulation index, however, mirrored their variable abundances at different sites. Association of Cd with P suggested the influence of anthropogenic solid waste from fishing industry. It might have caused >41-fold enrichment of Cd and the Fe-Mn-oxides possibly acted as scavengers for 13-fold enrichment of As compared to UCC. Concentrations of Zn and Cr between ERL and ERM in 13% and 93% of the samples, and Ni > ERM in 87% of sediments suggest their bioavailability to seawater with a potential risk for coastal aquifers.

Increasing urbanization and anthropogenic activities of the last couple of decades have left significant amounts of plastic debris in both coastal and marine ecosystems. In this study, we estimated the abundance of microplastics (particle size < 5 mm) in the beach sediments of southernmost India at Kanyakumari by collecting sediments from harbors, coastal fishing villages/residential beaches, tourist beaches, and undisturbed coastal areas along the Indian Ocean.We recovered 343 particles (67% fiber and 33% fragment) from eight different stations by evaluating 50 g dry sediments (d.s.) from each location. All of them were secondary microplastics and most of them (i.e., 331 out of 343 particles) were transparent. Tourist beaches had the highest concentration (150 particles/50 g d.s.), followed by the harbors (99 particles/50 g d.s.). The undisturbed beach contained the least amount of microplastics, representing only 4.3% of the total recovered particles. Our study relates the abundance of microplastics to different degrees of anthropogenic activities. Further research, however, is required to identify the mechanism that influenced
their transport and deposition in the coastal sediments as well as to evaluate the possible interaction between microplastic particles and marine ecosystems.