Photo: Siddharth Kankaria / Research Matters
It was once thought that the oceans were far too vast for humankind to affect in any way. However, in the age of the Anthropocene, nothing is left untouched. We have, for far too long, suffered from ‘Ocean blindness’ . We have not only failed to understand the importance of the ocean, but also failed to see the how we have adversely impacted it.
We know embarrassingly little about these enormous water bodies, that cover over 71 percent of the earth’s surface, of which, we have merely explored 10 percent. Oceans sustain around 1.2 million species of plants and animals, or 50 percents of all the known species, and scientists estimate that in the long run, we could discover even more marine species, from around 2 million to a whopping 50 million!
In spite of oceans being the biggest home, today marine animals and plants can no more call it their peaceful abode! The threats they are facing are not only immense, but largely unnoticed. Unlike deforestation or air pollution, the environmental violence against marine ecosystems is unseen, as it happens under the surface. From overfishing to coral bleaching, we do not quite know the full extent of our actions.
Overfishing - a paramount threat
The demand for fish protein is rising, especially in developing countries that can increasingly afford such products. More than 85 percent of the world’s fisheries have been ‘overfished’ - or fished beyond the point where the fish population can never grow to its original size. The once abundant species like the Atlantic Bluefin tuna are at the risk of extinction now. The fishing industry has started to target increasingly bigger oceanic predators like tuna and groupers, which in turn is causing a population increase in smaller prey species like sardines and anchovies. Such manipulation of the ecosystem is reducing the resilience of oceanic communities, which could lead to its eventual collapse.
Unfortunately, fishing industries have started to adapt even more unsustainable practices of fishing like trawling. As explained on the website of the Marine Conservation Institute, bottom trawling is an industrial fishing method where a large net with heavy weights is dragged across the seafloor, scooping up everything in its path. Due to this nonselective method, over 90 percent of the organisms caught are not commercially useful and are simply discarded. This by-catch, or unintended catch, sometimes include centuries old corals or even endangered fish and turtle species. The nets used for trawling scrape the surface and displace and destroy the benthic (seafloor) habitats like coral reefs that support marine life. Trawling is widely practiced in India , but this January, the Indian government has assured to take steps to ‘phase out’ bottom trawling.
Ocean Pollution and Climate Change - a worse enemy for tomorrow
The other major problem that threatens the oceans is pollution. In February, 2017, a large oil spill occurred off the Ennore coast in Chennai when two container ships collided. The oil is said to have contained highly toxic and non biodegradable particles like lead and arsenic which will continue to affect marine life like fish, and affect the livelihoods of people who depend on it. Furthermore, oil can get into an animal's lungs, affecting its breathing, spelling disaster for marine birds and mammals.
Yet another major pollutant is plastic that is thrown into the oceans all over the world. India alone dumps 0.6 tonnes of plastic into the ocean each year. The world’s plastic keeps floating around, being carried by the oceanic currents. At a site in the Pacific ocean, several such currents meet forming a gigantic garbage island three times bigger than the state of Uttar Pradesh! This garbage patch is mostly composed of miniscule ‘micro-plastics’. Plastics do not degrade, but due to the action of the sunlight, they do break into smaller and smaller pieces. When such debris are smaller than 5 millimeters in length, then they are known as a ‘micro-plastics’. These pieces easily enter the food chain when small fish, turtles, mammals and birds mistake them for food. Plastic enters and accumulates with each trophic level, killing several organisms along the food chain.
Not only is the ocean the world’s dumpyard, it is also the carbon sink where most of anthropogenic carbon dioxide is sequestered. Due to the increase in dissolved carbon dioxide, the water has become more acidic and warmer due to the rise in global temperature. These two factors are causing large scale coral bleaching and death. This has prompted several scientists to believe that the Great Barrier Reef in Australia will soon perish.
The ocean also acts as a vital cog in the earth’s climate system. It is the largest absorber of solar energy on earth. However, due to the recent increase in greenhouse gases causing unprecedented global warming, it is estimated that the ocean absorbs 25% of CO2 emissions and 90% of the heat associated with climate change.
The oceans are a ticking time bomb because eventually the heat stored will be dissipated in some form. It is because of the oceans that the Earth’s climate has been largely normalised. The ocean has been our greatest saviour against the global temperature rise, but it has started to face the brunt of it. The consequences will affect the entire planet.
Securing the future of our oceans
Despite being the biggest biosphere on earth, the oceans have been neglected in the environmental protection efforts for decades. The World Ocean Day was only officially recognised in 2008, almost 40 years after celebrating the first World Environment Day. In fact, the recent Paris Climate Summit in 2015 was the first one to have oceans featured for the first time in UNFCCC’s (United Nations Framework Convention on Climate Change) COP (Conference of Parties) meeting.
The world is increasingly realising the fact that oceans are vital in not only making the Earth a blue planet, but also keeping it green.
It is time we ourselves open our eyes to the importance of the oceans and take efforts to protect it. Several organisations in India like SSTCN (Student’s Sea Turtle Conservation Network), NCF (Nature Conservation Foundation), ANET (Andaman and Nicobar Environmental Team), Dakshin foundations and many more, are taking efforts to study and conserve marine ecosystems. It is time we contribute in protecting the oceans in our way by volunteering with clean up groups, rescues and rehabilitations, taking part in citizen science programs or promoting awareness.