Pollution is the introduction of harmful products not native to a particular environment. Specifically, a pollutant is a substance that causes damage to an organism by interfering with life processes. Ocean pollution can come from many sources such as crude or refined oil spills, agricultural and urban runoff, industrial waste, boat waste, and acid rain.
Sewage is a pollutant that is rich in nutrients which encourages the growth of certain types of algae. The introduction of sewage leads to an algal bloom resulting in an increase in the number of decomposing bacteria. These bacteria consume much of the oxygen and many organisms die as a result. This process is an example of eutrophication. Eutrophication is a set of physical, chemical, and biological changes that take place when excessive nutrients are introduced to the water.
Chemicals are also released into the oceans and kill organisms directly or accumulate in the bodies of higher organisms that feed on smaller organisms.
Oil pollutes the ocean from oil tankers and rigs, but also from the land as oil from cars and streets flows through runoffs into streams and eventually to the ocean.
Solid waste is also a large contributor to ocean pollution.
Agriculture, deforestation, and construction also contribute to ocean pollution. Even though these events take place on land, they cause large amounts of silt to accumulate in coastal areas and destroy ocean habitats.
Chlorofluorocarbons also known as CFC’s are causing a depletion in the Earth’s protective ozone layer. CFC’s are founding cleaning agenst, refrigerants, fire exthinguishng fluids, spray can propellants and insulating foams. This decline in the ozone layer effectivity can affect the plankton and decrease their productivity. Because the phytoplankton serve as the foundation for all marine live, the entire marine ecosystem would be affected.