Our oceans occupy a gigantic 71 percent of our planet out of which less than a mere 5% has actually been explored by humans. Most of earth’s life is an inhabitant of the ocean, with a largely mesmeric number of them still undiscovered. About 70 percent of the global oxygen is from aquatic plants mainly, aquatic algae. Even, when our marine life and their habitat makes such a huge contribution in sustaining our planet’s ecosystem, they haven’t escaped from man’s destruction. From pollution and global warming to over fishing and invasive species our oceans are enduring a lot and are desperate for rescue. Every form of pollution has its own way of destroying the seas.
Over, 8 million ton of trash is dumped in the sea every year comprising of plastic waste, industrial dump, medical and electronic wastes forming huge garbage patches. These patches make the sea poisonous for aquatic animals and flora causing loss of millions of organisms. Harmful chemicals especially from medical and e-wastes pollute ocean floors which enter into aquatic creatures contaminating the entire food chain finally affecting humans who feed on this marine life as well.
Another, major threat to oceans is eutrophication and algal bloom. When excessive fertilizers used in agricultural land gets washed into water bodies they result in over-growth of unwanted weeds and algae. This is known as harmful algal bloom which result in discoloration of water bodies and eutrophication. The phenomenon where uncontrolled plant growth depletes oxygen and nutrient content in water bodies making it unsustainable for other aquatic organisms is known as eutrophication.
Air pollution and global warming haven’t affected the oceans any less. Nitrogen oxides and sulfur oxides, which are the major shipping emissions affect marine life as well as the ozone layer. Excessive emission of greenhouse gases has led to an increase in earth’s temperature. Consequently, polar ice caps have been melting extensively resulting in wetland flooding. Moreover, global warming has increased the overall temperature of aquatic bodies. Marine animals have a particular temperature which is suitable for their survival, when this changes their livelihood is at stake. Added to this, corals release the algal component in them when water becomes too hot thus turning entirely white. This is known as coral bleaching. When this phenomenon occurs corals become weak and more vulnerable to diseases, their growth gets stunted, lifetime decreases and severe bleaching may even result in death of corals.
Temperature of our marine system also increases due to discharge from sewage treatment plants. Though, this discharge is free from harmful pollutants its temperature is not cooled down to make it suitable for aquatic life, when large quantities are discharged it has huge effects. Worst yet, untreated sewage and polluted industrial release is often discharged into the oceans directly or into rivers and lakes which eventually ends into the sea. The adversities caused by this ignorant act is self-explanatory.
Furthermore, the surge in carbon dioxide levels in the atmosphere known to be responsible for temperature increase also affects PH of waterbodies. When, CO2 dissolves into the water bodies it decreases the PH of water making it more acidic. This mainly affects small marine creature like mussels, planktons and oysters. Not just CO2 but any pollutant suspended in the air when dissolved in water bodies have unimaginably negative effects on aquatic life.
To be continued…….