Assessment of certain Anthropogenic Interventions and their Impacts along the Indian Coastline

Abstract

Coastal anthropogenic activities such as sand mining, disposal of untreated or partially treated sewage and industrial effluents from selected centres along Indian coastline and their possible impacts impairing the coastal environment are discussed with the data collected for two year period from eight maritime states of India. Destruction of macro benthos due to large scale sand mining along the Malabar coast was estimated to show an average of 2760 m-2 day-1 equivalent to 10.42 g m-2 day-1 (wet weight) registering maximum during the post monsoon season. Non biodegradable objects such as polythene carry bags, ropes and sachets were recovered in considerable quantities from the beaches (0.145-9.8 g m-2) as well as from the fishing grounds (32-85 g haul-1). The domestic sewage disposed to Visakhapatnam inshore area registered appreciable density of toxic algal species such as Gonyalux fragilis, Peridnium depressum and Porocentrum gracile. Annual average of mercury in soft tissues of crab Portunus sanguinolentus was found in very high levels from Veraval (2.90 ppm) followed by Tuticorin (2.39 ppm), Visakhapatnam (1.83 ppm) and Cochin (1.77 ppm). However, arsenic levels were very high in all the tissue samples collected from Tuticorin, Mandapam, Chennai and Visakhapatnam.