Although the ocean covers two-thirds of the surface of the Earth, it is surprisingly vulnerable to human influences such as overfishing, pollution from run-off, and dumping of waste from human activity. This kind of pollution can have serious economic and health impacts by killing marine life and damaging habitats and ecosystems.
The oceans are so vast and deep that until fairly recently, it was widely assumed that no matter how much trash and chemicals humans dumped into them, the effects would be insignificant. Obviously the policies on ocean dumping took an “out of sight- out of mind” approach.
The dumping of industrial, nuclear and other waste into oceans was legal until the early 1970’s when it became regulated; however, dumping still occurs illegally everywhere.
Common man-made pollutants that reach the ocean include pesticides, herbicides, chemical fertilizers, detergents, oil, sewage, plastics, and others… (About 8 million tons of plastic enters the ocean each year.)
Solid waste like bags, bottles, and other items dumped into the oceans from land or by ships at sea are frequently consumed, with often fatal effects, by marine mammals, fish, and birds that mistake it for food. Or for example some plastic material, particularly plastic bags, have been found blocking the breathing passages and stomachs of many marine species, including whales, dolphins, seals, and turtles.
(At least one million seabirds, and one-hundred thousand marine mammals die each year due to plastic pollution)
Almost every marine organism, from the tiniest plankton to whales and polar bears, is contaminated with man-made chemicals, such as pesticides and chemicals used in common consumer products.
Some of these chemicals enter the sea through deliberate dumping. But chemicals also enter the sea from land-based activities. Chemicals can escape into water, soil, and air during their manufacture, use, or disposal, as well as from accidental leaks or fires in products containing these chemicals. Once in the environment, they can travel for long distances in air and water, including ocean.
Tiny animals at the bottom of the food chain, such as plankton in the oceans, absorb the chemicals as they feed. Because they do not break down easily, the chemicals accumulate in these organisms, becoming much more concentrated in their bodies than in the surrounding water or soil. These organisms are eaten by small animals, and the concentration rises again. These animals are in turn eaten by larger animals, which can travel large distances with their even further increased chemical load.
Animals higher up the food chain, such as seals, can have contamination levels millions of times higher than the water in which they live. And polar bears, which feed on seals, can have contamination levels up to 3 billion times higher than their environment.
Many ocean pollutants are released into the environment far upstream from coastlines. Nitrogen-rich fertilizers applied by farmers inland, for example, end up in local streams, rivers, and groundwater and are eventually deposited in oceans. For example when it rains, when you water your lawn or wash your car, water picks up pollutants and carries them into our storm drains. Unlike the sewer system, most cities do not have treatment plants, or even filters, for this runoff. As a result, the pollutants found on streets, parking lots, buildings, yards ultimately enter streams and rivers, and eventually flow directly into the ocean. The kinds of pollutants found in runoff include motor oil, trash, pet waste, fertilizers, pesticides and also dirt.
Oil spils also cause huge damage to the marine environment – but in fact are responsible for only around 12% of the oil entering the seas each year. Almost 40% comes down drains and rivers as waste and runoff from cities and industry. And also millions of motor vehicle engines drop small amounts of oil each day onto roads and parking lots. Much of this, too, makes its way to the sea.
A Dutch teenager has invented a device that he claims could clean up some 20 billion tonnes of plastic waste from the world’s oceans. This concept is designed to be self sufficient and harness energy from the sun and waves. His invention could even make money by selling the plastic collected from the oceans.
…So we will see if this really works…