The oceans cover nearly three-fourth of earth’s surface. Ocean has been the source of many needs of man from the time immemorial.
The rapid growth of human population and the advancement of industrialization have exerted great pressure on the resources and the environment of oceans.
According to recent data, about 35 km3 of sewage and 3.5 km3 of industrial wastes are released annually into the coastal waters of India. In addition, the offshore oil installations have added another stress on the ocean environment. The recent exploration of the oil well in the “Bombay high” invoked a great concern about growing dangers of pollution of the ocean water.
The increasing exploitation of certain economically important red and brown algae without any proper conservation and indiscriminate mining of coral stones for industrial purpose, eliminating the substratum for the sea algae to grow are the serious problems which need our immediate attention.
Conservation and Management of Ocean Resources:
Land resources are depleting at a tremendous rate and in view of this, humans have started the exploitation of the natural resources from the oceans. Oceans have both biotic and abiotic resources, which may be in the form of renewable and non-renewable resources. Food resources are renewable which are obtained from the plants and animals of the seas whereas most of the mineral resources are non-renewable.
Biotic resources of the seas include fishes, crustaceans, molluscs, corals, reptiles and mammals. Among plants, seaweeds including marine algae, mangrove forests and some other plants are found that are economically important (Fig. 15.5).
Seaweeds, which were previously considered a nuisance, could offer an alternative source for food because of their high nutritive value. Seaweeds are also used as pharmaceuticals, textile, fodder, fertilizer and biomass. It has been estimated that the total annual yield of seaweeds is about 1 lakh tonne.
It has been estimated that the total annual yield of sea weeds in the country is 50 000 tons and it may reach to one lakh tons if all the precautions are taken in utilizing the resources. Planktons (phyto-planktons and zooplanktons) provide rich nutrition. Scientists are now interested in evolving methods of directly converting the plankton into food so that the food supply may be considerably enhanced and utilized for overpopulated world.
Mangrove forests are more common in the sea coasts. These act as guard. The reclamation of saline soil by enriching the coastal soils with organic matter thereby facilitating other plants to grow and the control of soil erosion in coasts are the main contribution of mangrove forests. It is a matter of great concern that these forests are being damaged at an alarming rate which expose sea coasts to the tides and cyclones. An important step in this direction is to replace the slow growing mangroves by fast growing trees along the coasts and thus provide an alternate supply of fuel to the people.
Among abiotic resources, energy in the form of waves, tides, thermal ocean currents; petroleum, oil, gas and mineral substances in various forms are available. Thus, the oceans are a great source of minerals to meet the growing demands.
The harnessing of the ocean resources is of great importance today, as humankind will get alternative sources of food and energy when our land resources will be in short supply. It is necessary to have a plan of action based on sustained utilization but not exploitation. Without proper management, the resources can be threatened and countries can fail to achieve the economic and social benefits. Therefore, considering the importance of marine resources, great care must be taken to preserve them and their environment.
The following methods for conservation and management of marine resources should be followed:
1. There is an urgent need to protect the mangrove forests for maintaining the ecological balance in coastal areas.
2. Seaweeds, corals and turtles are very useful components of the marine ecosystem as they maintain a balance in the environment. The interrelationship of such flora and fauna is of great importance in the management of biotic as well as abiotic components such as, certain mineral resources.
3. It is necessary to initiate researches on the various oceanic minerals and subsequently plan for monitoring the mining and extraction on keeping in view the international laws.
4. It is necessary to evolve inter-disciplinary action to encourage and support the collaboration among scientists from the different areas.
5. The weather and climate information should be relayed through media like television, radio, news bulletins, etc.
6. There should be integrated efforts for ensuring effective treatment of the effluents before disposing them into the sea.
7. In the coastal areas and estuaries, mangroves can harbour large quantities of prawn, etc. Hatcheries can be established for prawns in the marshes of mangroves and estuaries tor sustained yield.
8. The participation of the student and the coastal population is necessary to make them aware about oceans and ocean resources.
It is a well established fact that the ocean surface of 1 cm thickness known as surface micro-layer plays a crucial role in air-sea interaction. Detailed study of this layer is important in meteorology, agriculture and pollution. This micro-layer transfers not only energy and water vapour but also rich nutrients like N.P.K. into the atmosphere. Oil spills and other pollutants over the ocean concentrate in this micro-layer and finally enter the food chain through marine organisms.
Coral Reef is a ridge or elevated part of a relatively shallow area of the seafloor. It is formed by a rocklike accumulation of calcareous (calcium-containing) skeletons of coral animals, calcareous red algae and molluscs, which form an important marine habitat. Built up layer-by-layer, by the corals growing on top of the skeletons of past generations, coral reefs grow upward at the rate of 1 to 20 cm per year. Coral reefs are one of the most productive and diverse ecosystems on the earth (Fig. 15.6)
Coral reefs, which are the largest, oldest, most diverse and most beautiful communities of plants and animals, have been severely damaged. If human activities are not controlled, it is estimated that 60% of the world coral reefs could collapse in the next twenty years.
The corals are the main source of calcium carbonate and are also used in the preparation of lime, cement, calcium carbide, building blocks and construction of roads, etc. Coral reefs provide habitat to a vast variety of marine plants and animals. About 1 million species are associated with coral reefs. These organisms are the source of many useful chemicals and medicines. Coral reefs have long been the main source of protein for coastal people. With the modem preservation methods, fish and other food organisms from the coral reefs are now eaten by many people.
The excessive exploitation of coral reefs is alarming. It has caused severe destruction of both in the habitat and reef-building organisms. In recent years, attempts are being made to protect some of the coral reefs by declaring the areas as National Parks. Gujarat and Tamil Nadu have established National Parks for protecting the marine ecosystem in the Gulf of Kutch and Mannar respectively.
The task of harnessing the potential of ocean resources for development purposes is of great importance. We should pay our attention to the development of necessary resources of ocean when our resources are .n short supply. Now much awareness is needed by the National go— and International agencies including United Nations about studying the ocean environment, it is necessary to know about the physics chemistry biology and geology of the ocean. It is essential that in ocean-oriented programme, lawyers, economists, Tulessmfn, scientists and social workers should be involved in the policy making decisions.