Ocean Pollution By: Mahbubar Rahman

                  Ocean pollution, also known as marine pollution, is the spreading of harmful substances such as oil, plastic, industrial and agricultural waste and chemical particles into the ocean. Ocean pollution can harm marine organisms by destroying marine habitats. According to the United Nations Environment Programme (UNEP), land-based activities are responsible for as much as 80 percent of the pollutant load in coastal waters and deep oceans. Most of the marine pollution enters into the ocean by land runoff. Some of the pollution first runs into a river, and then the river water enters the sea carrying a staggering load of pollutants accumulated along the river’s entire length. In agricultural sites, runoff pollution sources such as livestock wastes, nutrients from fertilizers, herbicides, and pesticides can drain from fields into the ocean. In urban areas, runoff carries an array of pollutants; wastes deposited by motor vehicles, including gasoline, oil, grease, and heavy metals, sediment from construction sites; herbicides and pesticides from lawns and gardens, road salts, viruses and bacteria from inefficient septic systems, and spilled chemicals from industrial sites. Shipping spills is another major pollution for the ocean. Ships often carry toxic substances such as oil, liquefied natural gas, pesticides, and industrial chemicals. Shipwrecks can lead to the release of these chemicals and result in serious damage to marine life. Another major pollution source is dumping plastic items into the ocean, which can cause harm to the larger animals of the sea. They can trap mammals, diving birds, or turtles, causing them to drown. Fishing gear lost overboard can continue to drift, snaring fish and entangling seabirds. Marine animals routinely mistake plastic items for food, ingest them, and die.

           

            Most of the debris in the ocean does not decompose and remain there for years. This debris uses oxygen as it degrades. As a result of this, oxygen levels go down. Also, the Industrial and agricultural wastes are considered hazardous for marine life because chemicals from the pesticides can accumulate in the fatty tissue of animals, leading to failure in their reproductive system. Other chemicals from plastic and industrial decomposition do not get fully dissolved and sink to the bottom of the ocean. Small animals ingest these chemicals and are later eaten by large animals, which then affects the whole food chain. Marine pollution also affects human health. Humans consumes animals from the impacted food chain which affects their health as toxins from these contaminated animals get deposited in the tissues of people and can lead to cancer, birth defects or long term health problems.

Citations:

Ocean pollution. By: MacInnes, David F., Jr., Kähler, Karen N., Salem Press Encyclopedia, January, 2015