Human Impact on Marine Environments

Pollution is the insertion of non-natural or otherwise harmful substances into an environment. Pollution is any substance that’s harmful to an organism and interferes with its life systems and processes. Pollutants in the ocean are things such as spills of both refined and crude oil, acid rain, urban runoff, agricultural runoff, boat waste, and agricultural waste.

One example of pollution is sewage. Sewage has a high concentration of many nutrients and this encourages certain types of algae to grow. When the algae grow around the sewage, there is a great presence of algae growth. The more algae in an area, the more bacteria the algae decompose. These bacteria consume a great amount of the oxygen in the area, and, as a result, many organisms die because they don’t have sufficient levels of oxygen to be able to function properly. This is called eutrophication. Eutrophication is the result of the changes, biological, chemical, and physical, that occur when the water is saturated with excessive nutrients.

Chemicals are another potential pollutant. They leak into the water and poison organisms. Sometimes however the toxic chemicals simply accumulate in the bodies of larger creatures that eat smaller organisms.

Oil, both crude and refined oil, is also a type of pollution. Oil leaks of oil rigs and tankers and into the ocean to pollute it. Oil also comes from cars. It leaks onto the streets, then washes into local waterways. And eventually, the oil gets carried to the ocean through the use of the smaller streams and rivers.

Another substance that pollutes the ocean is solid waste. Certain acts such as deforestation, construction, and agriculture produce a great amount of silt. So, although they occur on land, the large volume of silt they create washes into the ocean and pollutes the water. The silt accumulates in the water, particularly coastal areas, and destroys the oceanic ecosystems and habitats.

Chlorofluorocarbons are another pollution issue. They are also called CFCs and they are found in many common household products such as spray can propellants, insulating foams, fire extinguishing liquids, refrigerants, and cleaning agents. CFCs are depleting the ozone layer. This is why they’re considered a pollutant. Because when the ozone layer is depleted, and its efficacy lessened, the phytoplankton’s photosynthetic properties are affected for the worse. Plankton serves as the base for all marine life, when phytoplankton suffers, the whole ecosystem is affected.