Oceans cover around About 71% of the Earth’s surface. The oceans play a vital role in the water cycle and are also rich in biodiversity and minerals. Furthermore, about half of the world’s population lives within 200 kilometers of a coastline. But we humans are polluting them by putting plastics, garbage, chemicals, and sewage.
1. Marine debris
Marine debris, also known as marine litter, is any man-made solid material that enters the marine environment through dumping, littering, rivers, streams, or drains. The major sources of debris are ports, river, stream, drain, direct dumping in the ocean, and overflowing sewage systems. Also, careless beach visitors throw plastic bottles, plastic bags, disposable glass, and coconut peels anywhere, which eventually carried into the sea by wind and sea waves. The majority of debris found in the ocean contains plastic items, and it affects marine wildlife, human health, and coastal habitats.
Mining in the sea is carried out by targeting polymetallic nodules 1400–3700 meter below the surface, or around active and extinct hydrothermal pores. Due to mining heavy metals accumulate deep in the ocean and damage the marine ecosystem.
Most of the world’s plastic is dumped into the oceans. Plastic items lying on the ground here and there, when it rains, flows with water into rivers and then drains into the ocean.
Crude oil or petroleum spillage
The main route for oil transportation is the sea. About 20-25 percent of the oil percolates into the sea due to sea storms and strong waves. Accidents of ships have also spread oil several times throughout the ocean due to tanker leaks. In 1978, an oil carrier crashed along the coast in France, oil spilled into the sea for several kilometers.
- When plastic is eaten by sea creatures, this plastic gets trapped in their lungs or respiratory tract and they die.
- When oil spills into the ocean, a layer of oil forms over the water, causing the oxygen content in the water to decrease, which eventually damages marine life.
- Some toxics such as pesticides, DDT, PCB, furan, TBT, radioactive wastes, phenols, and dioxins accumulate in tissue cells of marine organisms, which is a threat to their lives.
- Eating seafood can cause fatal diseases like cancer.
- Wastewater treatment plants should be installed at ports to prevent oil pollution.
- Proper safety measures should be taken in the ships so that oil does not leak under any circumstances.
- The oil tank should be constructed with two walls so that when the outer wall is damaged, the inner wall can protect the tanker. and the oil does not leak.
- Every country should make legal rules to clean beach waste.