Inherent in nature is the sense of harmony and order. However, in the last few decades we have mindlessly damaged the beauty of our planet Earth. The extensive degradation of our environment is the consequence of increase in population, increase in human needs, urbanisation and rapid industria-lisation. In this alteration of the environment, man has forgotten environmental ethics and has threatened the very existence of living organisms and the earth. Professor George Wald has summarised in the Heritage:
"Three billion years of life, three million years of man-like creatures, ten thousand years of civilisation and a mere 200 years of the industrial revolution have brought us to the brink of disaster."
During these 200 years, the sciences have led to a deeper understanding of processes in the physical and biological world as also the destruction of delicate ecological processes, leading to several unnatural phenomena. Our air, land and water are polluted, causing irreparable damage to animals and plants. If this trend continues, one apprehends that it may endanger the lives of living species, destroy the atmosphere, oceans and other water resources, converting the earth into a desolate lunar-like surface.
The Oceans
The oceans and their marginal seas cover nearly 71 per cent of the earth s surface, with an average depth of 3,795 metres. The exposed land occupies the remaining 29 per cent of the planetary surface and has a mean elevation of only 840 metres. An ocean is one of the areas of salt water which occur on the surface of the earth.
There is an old saying to the effect that the earth has six continents and seven seas. However, those conducting oceanic research generally recognise the existence of three major oceans: the Pacific, Atlantic and Indian. Arbitrary boundaries separate these three bodies of water in the southern hemisphere. However, water properties, ocean currents and biological population do not necessarily recognise these boundaries.
Economic Aspects of Oceans
The sea is generally accepted by scientists as the place where life began on earth. Without the sea, life as it is known today could not exist. Among other functions, it acts as a great heat reservoir, levelling the temperature extremes that would otherwise prevail over the earth and expand the desert areas. The oceans provide an inexpensive form of transportation, and the coasts serve as a major recreational site. The ocean is a valuable source of food, including almost all the table salt. It is also a potentially important source of energy and minerals, all of which are required in ever-increasing quantities by industrialised and developing nations alike.
Indian Ocean-Perspectives and Problems
The Indian Ocean is the third largest of the world s oceans, covering 73 million square kilometres. Ringed by 37 predominantly developing countries from Eastern Africa to South East Asia and Western Australia, the Indian Ocean bears almost one-third of the world s population, yet is the last major world region lacking a comprehensive conservation and management strategy. Fisheries in the open ocean and populations in coastal regions rely heavily on marine resources for subsistence and commerce.
Unfortunately, most of the valuable Indian coast is treated as a garbage dump. Industries and municipalities discharge untreated effluents into the seas, polluting not just the water, but the land as well.
An investigation on coastal pollution during the last decade has identified hot spots along the east and west coasts. The rapidly industrialising cities such as Mumbai, Calcutta and Vishakha-patnam were found to pollute the coastal water with heavy metals and oil. Discharge of sewage into the sea is a global problem. The flux of pesticides in the east coast is greater due to intense agricultural activities. Cement and steel plants rip corals from reefs, unmindful of the resultant losses caused to inland areas on account of shore erosion.
After industry, unfettered tourism, however, is perhaps the single largest threat to beaches today.
Local populations are dest-roying the mangrove system which is the important nursery for many marine species for fuel and fodder. The trampling of mangroves in search of these is causing irreparable damage to the mangrove system.
Such interferences adversely affect the breeding success of innumerable marine organisms such as shrimps, lobsters, sharks and other fish which spawn inland. Falling fish catches near our shores can safely be attributed to the abuse of marine ecosystems (coupled with the destruction of spawning grounds by mechanised trawlers). By destroying these nurseries, we are literally snatching the only reliable protein source available to millions of rural poor who live on and near our coasts.
Amongst the least known and most unique animals of the coastal zone is the dugong or sea cow from the Gulf of Kutch and the Gulf of Mannar. Today it is an uncommon animal. Even the distribution of the estuarine crocodile is very fragmented today. The five species of sea turtles that visit the Indian coast, the olive ridley, the hawksbill, the green turtle, the loggerhead and the leatherback are all threatened. Their breeding grounds are fast vanishing.
I would now like to highlight a few of the case studies based on my personal experience relating to my work in Bhitarkanika sanctuary, which until recently also included the Gahirmatha area, the largest rookery of sea turtles.
Marine turtles/Gahirmatha
Sea turtles have been roaming the world for the last 150 million years. They are not restricted by ephemeral boundaries, and, therefore, are truly international.
Five of the world s seven species of marine turtles inhabit the Northern Indian Ocean: the olive ridley, the hawksbill, the green turtle, the leatherback and the loggerhead. Historically, the Northern Indian Ocean has supported large populations of marine turtles. Marine turtle populations have declined as a result of the degradation or destruction of the habitat on which they depend. They have also declined as a result of the decades of traditional and commercial use. Marine turtle populations and habitats, if protected and managed, make a valuable cultural, ecological and economic resource.
They are a shared resource of immense value to the nations around the Northern Indian Ocean, namely Malaysia, Thailand, Bangladesh, India, Pakistan, Maldives, Sri Lanka, Oman and Saudi Arabia. Similarly country representatives of the Western Indian Ocean have drafted a strategy for Western Indian Ocean marine turtles. Gahirmatha has now been declared a marine sanctuary (area: 1.435 sq km) since September 27, 1997.
Bhitarkanika Sanctuary
The deltaic region of rivers Brahmani and Baitrani, covering an area of 672 sq km, has been declared as a sanctuary since April 22, 1975. With a rich flora of primarily mangrove plants, it is rich in species diversity, having 62 out of the total or 67 species of mangroves in India. Being equally rich in fauna, it has the largest population of estuarine crocodile (Crocodylus porosus) which also includes the largest crocodile existing in India. This is due to the successful rehabilitation programme which was undertaken in 1975 through which hundreds of hatchlings were reared and released into the river system inside the sanctuary. Other endangered animals include the largest Indian lizard - the water monitor (Varanus salvator), king cobra, rare estuarine turtle (Pelochelys bibroni), white bellied sea eagles and fishing cats. It also receives a good number of migratory birds in season. However, encroachment, fishing, illegal aquaculture and increase in the migrant population is threatening the very existence of the sanctuary. Pressure on mangrove plants and wading in the mangroves for prawn seeds by local people as well as incidence of poaching is on the increase.
Acknowledgments
I wish to thank Shri S K Patnaik, Conservator of Forests, Government of Orissa and Shri S K Kar, Research Officer, Wildlife Division, for providing the data on Bhitarkanika.
The above article is excerpted from a speech made in New Delhi by Padmashree Professor P Mohanty-Hejmadi, Vice Chancellor, Sambalpur University, Orissa on June 5, 1998, on the occasion of World Environment Day and the National Museum of Natural History Foundation Day.