The Oceans, the sole factor behind Earth’s christening as the “Blue Planet,” forms one of the subsystems in the Earth’s holistic system with a distinct individuality of its own. Apart from being the primary source of all water on the earth, acting thus as a reservoir pool, they are the prime movers behind atmosphere and its associated changes. And, these two in conjunction don the role of regulators and moderators of the earth’s climate. From being cradle of primeval life and accounting for more than 71% of the earth’s surface which they embellish, the oceans have been indispensable to mankind since antiquity. They are rich not only in biodiversity, but are also endowed with profuse tapped and untapped resources that man has always looked upon when the very question of survival comes at stake. Marine resources or the resources derived from sea waters have assumed profound significance today in the backdrop of problems concatenated to mindless development and industrialisation, unbridled population growth and the consequent exhaustion of land resources.
Marine resources encompasses within its ambit plethora of resources. First and foremost, the biodiversity enwombed in the marine ecosystem is in itself a great wealth we have. With food yields from land reaching saturation point, the oceans can be harnessed to meet this basic necessity. Ocean foods are rich in vitamin B-12, polyunsaturated fats, proteins and amino acids. Fishes, constituting 90% of all the biotic resources extracted from oceans and 10% of total animal protein consumed by man, are the most important of marine foods. Mackerel, tuna, anchovies, cod, haddock and salmon comprise bulk of the world’s fish catches. The coastal margins of the mid-latitudes, on account of conducive conditions, are the biggest fish producing areas. Some of the major fish-producing areas are: The North-West Pacific; The North-East Atlantic; South-East Pacific off the coast of South America; the West Central Pacific and the North-West Atlantic, including Grand Bank and Georges Bank area. However, barring aside the fresh water catches, the overall world marine production has been dwindling since 1989. Recent trends have been towards aquaculture, but it is polluting. Sea weeds, krills, squids, myctophids are other marine foods. Besides, whaling is done for industrial and commercial purposes. The oceans also provide curative medicines, cattle and poultry fees, fertilisers, precious pearls, semi-precious stones, calcium carbonate deposits. However, less than 2% of total world food comes from the oceans. So, it needs to be handled with care. Overfishing on Lake Victoria has depleted the stock of Nile Perch, a fierce predator fish, by 81 per cent in three years
Minerals form main component of marine resources utilised by man. They occur both in solution and suspension. Dissolved salts common in sea waters include common salts, magnesium nd bromine. Among the surfacial resources, the continental shelves provide maximum variety such as copper, tin, gold, diamond, and nuclear fuels like thorium and titanium. Recently, Japan collected rare metals like Vanadium and Uranium from the seas. Organic phosphates, phosphorite and calcium is derived mainly from the corals. Though the continental slopes are less rich in terms of variety of minerals, it is well-made by the abyssal plains which are known for biogenous deposits called oozes and polymetallic nodules of great economic importance. They contain manganese iron and scarce metals like copper, nickel and cobalt. The Central Indian Ocean is a rich site for these nodules. India has the distinction of being the first country in the world to have been allotted a mining site in the area. Poly-metallic sulphides and salt brines are associated with fractures zone s in the earth’s crust. The sub-surfacial marine deposits include (a) Coal found in North Sea and south eastern coast of Africa; (b) Tin in Indonesia; (c) Sulphur along the Gulf of Mexico Coast. However, the most important of the sub-surfacial deposits is oil and natural gas which accounts for about 90% of the mineral value obtained from the oceans. In fact, mineral oil being the single largest commodity in international trade in terms of value and volume has the most important source of commercial energy in the 20th century. The major offshore oilfields (constituting about 35% of world production) are in Gulf of Mexico, Persian Gulf, North Sea; and coasts of Australia, California and the Arctic Ocean. Nearly 80% of the countries are exploiting mineral oil from the continental shelf areas.
Marine waters are also rich in various renewable energy resources. Apart from being a treasure house of conventional mineral energy resources such as fossil fuels and atomic minerals, the ocean water itself can be a source of energy by the application of advanced knowledge and technology. Tidal power based on the rise and fall of tides is harnessed on the coasts of Bay of Fundy in North America, Argentina, Great Britain, France and Russia. The first tidal energy plant was established in the LaRance Valley on the Brittany Coast and another in the White Sea. Wave power based on the motion of waters has also tremendous potential for energy generation. In India, wave power plants have been set up in Car Nicobar. Ocean Thermal Energy Conversion (OTEC) or Solar Sea Power Plants based on temperature differences (of 200c) between the warm surface and cold deep waters is also being used. India has the distinction of having built the world’s first OTEC plant in the Indian Ocean. OTEC system is also employed in Ivory Coast, Belgium and Cuba. Reverse Osmosis based on temperature differences between the sea surface and air above, and ocean currents can also be used for generating power. Biomass Conversion method using marine biomass also produces energy. Besides, methane gas hydrates’ sources can also be tapped. However, due to cost of effectiveness question and dearth of proper technology, most of these projects haven’t got off to a desired start. Last, but not the least, the sea water itself is a resource. With receding fresh water tables, the desalination of sea water can be an alternative mankind can look forward with optimism in the future. A desalination plant is working in Kavaratthi in India. However, large scale desalination is not cost effective.
Apart from all the resources which man gets, let us not be unmindful of the aesthetic value of the oceans. The blue waters, rising and dancing, proffers a view which can bring comfort and solace to the disturbed souls in today’s fast-paced world. Who can ignore the mesmerizing beauty of coral reefs. One of the several marine ecosystems, coral reefs wean and nurture a bewildering variety of organisms. It is perhaps for this very reason that they are known as “Neptune’s Goblets.” Coral reefs harbour the highest concentration of marine biodiversity in the world, form the basis of ecosystems and food webs that sustain communities and provide coastal protection. However, according to recent research, climate change and human impacts are placing one-third of reefs at serious risk of extinction. Areas at risk include the Caribbean and the Coral Triangle in the western Pacific. Humans can have negative impacts on coral reefs through a number of means, including increased coastal development, sedimentation due to poor land-use and watershed management, sewage discharge, pollution from agrochemicals, coral mining and over-fishing. These impacts reduce the resilience of corals to withstand global threats from a rise in sea surface temperatures and increased ocean acidification arising from climate change. Higher temperatures lead to heat stress, which causes the coral to expel the zooxanthellate algae that live in their tissues in a protective, symbiotic relationship. This increases the risk of mass coral bleaching and mortality from diseases, some of which can kill 500 year old colonies within months. Additionally, ocean acidification is reducing ocean carbonate ion concentrations which in turn limits the ability of corals to build skeletons and reef structures. As per a recent data, Global warming is slowing the growth of corals on the world’s largest reef, the Great Barrier Reef in Australia. Scientists down under have shown that the growth of the most robust corals on the reef has slowed 13 per cent since 1990. At this rate, the corals would stop growing altogether by 2050.
Thus, the oceans by dint of being a hidden treasure can be panacea to a multitude of compulsions sequestering mankind today. It is irony that man meddles with and ultimately ruins those very bases which nurture and sustain him. The oceans, too, have met the same predicament. Pollution, by poor land use practices, industrial effluents, urban sewage, overfishing, dumping of radioactive wastes, cutting of marine forests and filling wetlands have cumulutatively jeopardized the fragile marine ecosystem. The increase in coral bleaching and El Nino are testimony to this. The need of the hour is to utilise marine resources judiciously and in a sustainable manner. The declaration of 1997 and 1998 as the International Years for Coral reefs and Oceans respectively was a modicum step in this direction. Man cannot be so inhumane towards the last frontier that he has with himself!