CHAPTER - 25 250 Years of Marine Biodiversity Scenarios in India What Will Persist?
K. Venkataraman
National Centre for Sustainable Coastal Management, Anna University Campus, Chennai-600025, India
The Indian subcontinent is surrounded by three seas and one ocean viz., Arabian Sea in the west, Bay of Bengal and Andaman Sea in the east and Indian Ocean in the south. Coastal and marine ecosystems of India play a vital role in India’s blue economy by virtue of their resources, productive habitats and rich biodiversity. India has a long coastline of 7,516 km of which, the mainland accounts for 5,422 km, Lakshadweep coast extends 132 km and Andaman and Nicobar Islands have coastline of 1,962 km. The coastal area is assuming greater importance in recent years, owing to increasing human population, urbanization and accelerated developmental activities. Nearly 250+ million people live within a distance of 50 km from the coast. The coastal regions are thus, an important place of human activity and the coastal ecosystems are now extremely disturbed and very much threatened. Current approaches to the management goals of coastal resources were not accomplished and the coastal environments and resources are being rapidly degraded and eroded in India.
The continental regions and the offshore islands and a very wide range of coastal ecosystems such as estuaries, lagoons, mangroves, backwaters, salt marshes, rocky coasts, sandy stretches and coral reefs, are characterized by unique biotic and abiotic properties and processes. A network of 14 major, 44 medium and numerous minor rivers together with their tributaries drain in to the Arabian Sea, Bay of Bengal and Indian Ocean. Other than these mainland coasts, there is Lakshadweep in the south Arabian Sea and Andaman and Nicobar in the eastern Bay of Bengal. The West Coast is generally exposed to heavy surf and rocky shores and headlands. The East Coast is generally shelving with beaches, lagoons, deltas and marshes. Conserving the marine biodiversity what we have today is hampered by lack of capacity to mitigate the climate change effects including awareness, outreach as well as our ability to predict the climate change impacts, what would survive in India and lack of data relating to changes in biodiversity of those environments. The present speech provides a comprehension into the biodiversity in India with a question on what will remain for future.
Material and Methods
The present synthesis of what is known of coastal and marine biodiversity in India is based mainly on historical, systematic accounts, records and reports of the Zoological Survey of India as well as other research organizations such as Central Marine Fisheries Research Institute, National Institute of Oceanography, Bombay Natural History Society, Central Salt and Marine Chemicals Research Institute; Fishery Survey of India, Geological Survey of India, Indian Institute of Science, M.S. Swaminathan Research Foundation and Wild Life Institute of India.
Results and Discussion
The inventory of marine fauna and flora through published literatures on coastal and marine biodiversity of India indicates that a total of 21,663 species of faunal and floral communities have been reported from seas around India (Venkataraman & Raghunathan, 2015). The data reveals that India contributes 6.44% of marine biodiversity in global scenario (Table 1 and 2). According to the legislation of Government of India, about 885 marine faunal species belonging to eight Phyla viz., Poriferea, Coelentrata, Arthropoda, Mollusca, Echinodermata, Pisces, Reptilia and Mammalia are protected under the legislation (Table 3) of different categories (Schedule I, II, III, IV) as their natural population is dwindling. The taxonomy and inventory of many of the minor groups particularly invertebrates especially sponges, octocorals, ctenophores, polychaetes, sipunculates, polyclads, opisthobranchs, meiofauna, isopods, amphipods, rotifers, nemerteans, endoprocta, ectoprocta, loricifera, acanthocephala, anomura, nemertina, gastotricha, gnathostomulida, kinorhyncha, echiura, bryozoa, tardigrada, pogonophora, and tunicates remain a challenge to specialists and as a result these taxa continue to be inadequately known from Indian seas (Venkataraman & Wafar, 2005). However, considerable knowledge on the taxonomy of groups such as seaweeds, seagrasses, mangroves, hard corals, crustaceans, molluscs, echinoderms, fishes, reptiles and marine mammals are available in India. Moreover, most of the data on marine biodiversity have been collected from surveys up to the maximum depth of 200 m in the continental shelf The gaps in knowledge extend to several smaller taxa and to large parts of the shelf and deep sea ecosystems, including seamounts (Wafer et al., 2011). The data provided in this paper warrants the continued taxonomic research in least studied/unknown groups in light of current threats to marine biodiversity. We may of course never know the full extent of biodiversity in any of the world’s oceans and the rate at which we increase our understanding is likely to be lowest in seas around India. The impacts of climate change will alter coastal marine ecosystems affecting the range of species and their ecology at a rate faster than it is recorded (Keesing and Irvine, 2005).
