Pollution of the oceans, which can simply be defined as contamination of the ocean with harmful or foreign materials, is categorized under water pollution because it constitutes the largest and the most crucial water body in the entire planet.
Ocean pollution has increasingly become an important matter due to the heightened human activities that have extensively affected the cleanliness of the oceans. Fishing practices and marine life have been adversely affected while the coastal habitats are increasingly destroyed at an alarming rate. It’s thus an important call to manage and protect our oceans so as to maintain the ocean health index and to ensure continuity of the life on earth.
Foremost of all, it’s paramount to know the primary causes of ocean pollution before the solutions are determined.
- The Oil Industry and Oil Spills
The oil industry is accountable for most of the episodic far-reaching oil spills which have proved to be very catastrophic and even threatened the survival of marine life. A perfect example is the 2012 B.P. oil spill that killed thousands of marine species including birds, fish, turtles and sea otters. Oil spills are thus a primary source of ocean pollution, and most of the spills arise from offshore drilling rigs, ships, and boat leakages.
Oil spills can last for years in the oceans, and it takes a lot of resources and millions of dollars to remove the oils from the oceans. Ship accidents have also substantially contributed to oceanic oil spills, and some people deliberately discharge oil into the ocean. Leaking of natural oil as well contributes pollution in the ocean, but to a very small degree.
- Industrial Manufacturing Activities
The manufacturing processes of industries indirectly or directly release toxic and harmful substances which find a way to the oceans. Industrial processes pollute the oceans in various ways. The most common aspect is the direct dumping of waste liquids into oceans or other waterways that ultimately end up in the ocean. These waste liquids may contain harmful or toxic materials, and at times raise ocean water temperatures leading to what are termed as thermal pollution.
As a consequence, the marine lives that cannot tolerate higher aquatic temperatures die and may even be wiped out completely. In an indirect way, fumes and exhaust gasses from manufacturing industries result in the formation of acid rain. Furthermore, the chemicals emitted into the atmosphere condense and fall into the oceans causing contaminating.
In many instances, raw sewage has been dumped into oceans or water ways that find way into oceans. Commonly, sludge from sewage treatment plants is also discharged into the oceans. As much as the ocean is vast and has the potential to breakdown this crude waste naturally, the cumulative effects cause numerous damaging effects on marine life. Sewage and sludge dumping into ocean’s habitat usually contribute to reduced oxygen levels due to the growth of chemical nutrients, adversely affecting aquatic animals and plants.
- Agricultural and Farming Practices
Agricultural and farming practices substantially contribute to ocean pollution. Agricultural pesticides, fungicides, herbicides, chemical fertilizers, farm nutrients among other agricultural chemicals are highly toxic and often find way into the oceans through surface storm water runoff.
These materials are washed into the nearby rivers, streams and other waterways that finally reach the oceans. Pesticides, for instance, contain heavy metals like lead, copper and mercury which cause severe health impacts to humans when indirectly ingested by consuming intoxicated marine animals like fish.
Inland pollution is one of the biggest sources of ocean non-point pollution. People barely realize this, but it qualifies as a huge source of ocean pollution. It takes place when bits and pieces of plastics, cans, debris, dust, and trash slowly move and eventually find way into the oceans. Materials such as plastics and glass take hundreds of years in the oceans because they cannot decompose.
When these materials disintegrate into smaller pieces, they are ingested by the marine animals including fish, turtles, sea birds, crabs, and dolphins, gradually killing them over an extended period. The trash may also contain toxic chemicals which contaminate the oceans.
- Mining Activities in the Ocean
Mining activities in the deep sea is to a greater extent a practice that often causes ocean pollution. Drilling and dredging of the ocean floor to extract minerals and metal ores like zinc, cobalt, silver, aluminum and gold destroy the oceans and the coastal regions as the mining processes generate scores of sulfide deposits in the ocean.
Deep sea mining may have devastating environmental impacts and destroys the ocean floor especially the barriers against storms and vital fish breeding grounds. Also, it builds the toxicity levels in the mining areas and contributes to secondary consequences including leakages, oil spills, and corrosions that further destroy the marine ecosystem.
- Land Surface Runoff
Almost 80% of pollution to the ocean environment begins from the land and is carried to the ocean as a result of runoff. Numerous sources including trucks, cars, septic tanks, and petroleum find way into the ocean from the land via storm water runoff. For instance, thousands of automotive engines drop small amounts of oil onto the parking lots and roads which are carried into the ocean by stormwater runoff.
Other harmful contaminants like pesticides, fertilizers, sewer and trash from farms and wastelands flow over the land and into the ocean when it rains. The impacts have lead to dead zones, garbage patches, and growth of plants and chemical nutrients that suck up oxygen.