Ocean pollution making waves

Everybody is worried about how to swim across their sea of sorrows. But nobody is ready to bother about the sorrow of seas. Only a few environmentalists and scientists studying environmental and ecological problems of oceans know the depth of seas and width of their sorrows.  

Governments of various countries and voluntary organisations came forward and conducted a conference to address the problems associated with oceans in Canada on June 8, 1992, and thereafter the day is recognised as the World Oceans Day. 

Ten years later, the UN did declare June 8 as Oceans Day, but it is only from 2008 that it has been celebrating the day officially. Every year, the UN conference focuses on a central them, like Oceans for life (2010), The next wave of change (2012), Healthy Oceans (2015) etc. “Prevent Plastic Pollution and Encourage Healthy Ocean” is the central theme of the 2018 Oceans Day.

Occupying one-third of the earth’s surface, oceans remain a prime source for mankind for their living as well as well-being. Even though all the seas form a single ocean on earth, they are separated into five oceans geologically: Atlantic Ocean, Arctic Ocean, Antarctic Ocean, Pacific Ocean and Indian Ocean, namely. Even though the average depth of the oceans is 12,400 feet, sunrays cannot penetrate the seas not below 330-foot depth. Beyond this limit everything appears as sea of dark waters. 

Till today mankind is not able to break 5% of the secrets hidden beneath these dark waters in the sea. Ocean is the largest museum that is existing on the earth, comprising mountains, volcanoes, hot water springs, diversified species and many other things. The temperature of hot springs even exceeds an unbelievable range i.e., grater than 3600 degrees Celsius. 

Longest range of mounts that even do not exist on earth surface can be seen under the oceans. The mid ocean range mountains extend 56,000 km between Atlantic and Pacific oceans. Beneath the Australian coast, under the Pacific Ocean, there exists largest natural coral island, ‘Great Barrier Reef,’ extending up to 2,575 sqkm.

The negligence and greed of humans is posing ecological threat to the oceans. Overwhelming fishing is destroying biodiversity; adding to it is excess air pollution on the earth surface. The acidity of oceans is increasing due to high absorption rate of excessive carbon dioxide and harmful gasses. Poisonous and polluted gases are leading to extinction of valuable coal islands. Plastic is the major threat to oceans. 

According to reliable sources, plastic material in seas could weigh about 28 crore tonnes. By 2025, this may increase thrice in weight. Recently, in Pacific Ocean near Marian Trench, researchers discovered a plastic bag at 36,000-ft depth. They counted 3,000 such materials there, lying there for the last 30 years.  As much as 93% of this largest coral island vanished by 2016 itself. The floating wastage accumulated as great Pacific garbage patch is about 80,000 tones in weight. 

This patch extends 7 lakh sqkm between Hawai and California coasts. Galapagos Islands famous for biodiversity are in a danger due to plastic wastage. Between 1970 and 2012, around 49% of vertebrates living in seas perished – a total 39% of all kinds of species do not exist now.

We must be perturbed as oceans are turning mere ponds of poisonous waters. Oman coastal area has already become a prominent place for dead waters. The size of these dead waters is equal to that of a small country and is increasing day by day. 

There are many chances of such deadly waters existing at some other places across the five oceans. Many islands like Great Pacific Gyre now look like dumping yards of plastic waste. The plastic wastage area in Pacific Ocean greater than France in area. Not only air is polluted when fossil fuels are burnt, but also the carbon contents released in the process are absorbed by oceans. About 25% of these carbon gases are making the surface waters of oceans acidic. As this process speeds up, in future the waters of seas will not only taste salty but also become acids. 

According to Global Bio diversity Institute, during the last 200 years, the acidity of sea waters has grown by 30%.  Half the oxygen quantity required for living beings on the earth is supplied by oceans only. But unfortunately, oceans are absorbing 50 times more than carbon dioxide that is available in earth atmosphere. As carbon dioxide penetrates the deep seas, the oxygen content on the surface of seas is reducing drastically in size and they are becoming dead zones. In 1910, there were only about 10 such dead zones, whereas by 2010 theses dead zones increased to 500. 

The area of each such dead zone may extend up to 2.5 lakh sqkm. If the same situation continues, no living being can exist in oceans in nearby future. As much as 1.9 million sqkm solidified snow ocean was available near Alaska once upon a time. But gradually these snow regions are melting and flowing into Pacific Ocean. Every year 49 billion tonnes of snow is melting into the oceans, and every year, 180 tonnes of snow formed on earth surface are melting down into the seas.

Rivers originating in the Himalayan glaciers flow east and west for about 2,000 kilometers, providing drinking water for one-fourth of South Asians. During 2003-2009 due to increase in earth temperature, the melting point of these glaciers increased and, as a result, the regions across Ganges and Brahmaputra rivers were affected by severe floods.  Cyclones were very rare in good olden days, but these are happening once or twice every year, somewhere on earth’s surface. Main reason for frequent cyclones is increasing temperature on earth. 

As a result, seasonal cycle is also changing with temperature. Due to variable seasonal cycle, the Atlantic Ocean flow speed reduced by 15%, which is equivalent to 10 times that of Amazon River flow. Atlantic Ocean acts as a conditioner to convert hot water to cool near equator and vice versa near poles. But, as a result of the reduced flow speed, it is no more acting as a conditioner; as such, the problems underlying are unpredictable. 

Exploration of natural gases, oil and chemical deep-sea mining and urbanisation near coastal areas, establishing chemical factories, atomic plants, industries, shipyards, tourist hubs near sea coasts etc., are main factors behind the increasing plastic and other pollution content in oceans. There are rich mangrove forests along the sea coasts which are helpful in absorbing carbon dioxide and other polluted gases. But these forests are running out drastically, causing a great concern. 

Around the globe, 80% of these forests have vanished, with the result that carbon dioxide content increased enormously in the seas. This situation caused 11 species out of 70 rare species to disappear.

Now is the time to open our eyes and stall the grave effects of manmade pollution. If we remain nonchalant, these natural rich resources may not be there for our future generations. Everybody must come forward and join hands in reducing the use of plastic to preserve the health of our mighty oceans. 

By: Prof E Sreenivasa Reddy
(Writer is Professor, University College of Engineering, Acharya Nagarjuna University)