Human Impact on Marine Environments

Pollution is any substance that harms an organism and interferes with its life systems and processes. Examples of pollutants in the ocean include spills of 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, which causes certain types of algae to grow at faster rates, and this deregulated growth disturbs the entire ecosystem: more algae make way for more bacteria that feed on decomposed organic materials. Those bacteria use up a great amount of oxygen, causing a dysfunction in all the other organisms that also need oxygen. This is called eutrophication. Eutrophication is a consequence of biological, chemical, and physical changes that occur when the water is saturated with excessive nutrients.

Chemicals are another potential pollutant. They can leak into the water and end up poisoning organisms. Intoxication is particularly worse for larger animals, as toxic chemicals accumulate in their bodies after they eat smaller organisms.

Oil leaks from oil rigs and tankers into the ocean are another worrisome cause of pollution. Sometimes, oil also comes from cars, leaking onto the streets. This dirt is then washed 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 environmental actions, such as deforestation, construction, and agriculture, produce a great amount of silt. Although these issues originate on land, the large volume of silt created washes into the ocean and pollutes the water. The silt accumulates in the water, particularly in coastal areas, and destroys the oceanic ecosystems and habitats.

Chlorofluorocarbons are another pollution issue. Also called CFCs, 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, thus being considered a pollutant. When the ozone layer is depleted and its efficacy is lessened, the phytoplankton’s photosynthetic properties are affected for the worse. Plankton serves as the base for all marine life; when phytoplankton suffer, the whole ecosystem is impacted.

Referências

• POLLUTION IN OCEANS. Available at: https://www.nationalgeographic.com/environment/oceans/pollution. Accessed on: March 31, 2025.

• EUTROPHICATION AND OCEAN POLLUTION. Available at: https://www.nationalgeographic.org/encyclopedia/eutrophication/. Accessed on: March 31, 2025.

• OCEAN POLLUTION AND TOXIC CHEMICALS. Available at: https://oceanservice.noaa.gov/facts/oilpollution.html. Accessed on: March 31, 2025.

• SOLID WASTE AND OCEAN POLLUTION. Available at: https://www.oceanconservancy.org/trash-free-seas/plastics-in-the-ocean/. Accessed on: March 31, 2025.

• CHLOROFLUOROCARBONS (CFCs) AND THE OZONE LAYER. Available at: https://www.epa.gov/ozone-layer-protection/ozone-depleting-substances. Accessed on: March 31, 2025.