The Most Polluted Oceans: A Global Crisis

Plastic is the most common ocean pollutant, with bags, bottles, food containers, cutlery, wrappers, synthetic rope, and fishing items found in the ocean. Eighty per cent of marine litter comes from land-based sources, including storm drains, sewers, septic tanks, cars, trucks, boats, farms, ranches, and forest areas. One of the biggest sources of ocean pollution is nonpoint source pollution, which occurs as a result of runoff from land.

Plastic pollution

Plastic is the most common ocean pollutant. Eighty per cent of marine litter comes from land-based sources, including those far inland, via storm drains, sewers and other routes. The most common plastic items found in the ocean include bags, bottles, food containers, cutlery, wrappers, synthetic rope and fishing items.

According to the University of Cádiz, rope accounts for almost eight per cent of the plastics found in the ocean. The most likely source of this rope is the maritime industry, which includes the construction, repair and scrapping of vessels, and the transportation of cargo and other materials across the ocean. The University of Plymouth found that these ropes could be responsible for releasing huge amounts of microplastics into the ocean – up to 760 fragments per metre.

Kanapou Bay, on the Island of Kaho’olawe in Hawaii, is a hotspot for marine debris accumulation.

Nutrient pollution

When large tracts of land are ploughed, the exposed soil can erode during rainstorms. Much of this runoff flows to the sea, carrying with it agricultural fertilisers and pesticides. Oil from motor vehicles is another pollutant that enters the sea in this way.

Nonpoint source pollution

Eighty percent of marine pollution comes from land-based sources, including those far inland. One of the biggest sources of ocean pollution is nonpoint source pollution, which occurs as a result of runoff. Nonpoint source pollution includes many small sources, like septic tanks, cars, trucks, and boats, plus larger sources, such as farms, ranches, and forest areas.

Another example of nonpoint source pollution is nutrient pollution, which happens when excess nutrients, usually nitrogen and phosphorus, enter bodies of water and act as fertilizers. This can lead to the overgrowth of algae, which can harm marine life and reduce water quality. Nutrient pollution can come from a variety of sources, including agricultural runoff, septic systems, and even urban areas, where fertilised lawns and gardens can contribute to the problem.

While nonpoint source pollution may not be as visible as other forms of ocean pollution, such as plastic debris, it can have significant impacts on marine ecosystems. It can contribute to the degradation of water quality, harm marine life, and even impact human health. Addressing nonpoint source pollution requires a coordinated effort from a variety of stakeholders, including farmers, ranchers, and government agencies, to implement best practices and reduce the amount of pollution entering our oceans.

Industrial chemicals

The maritime industry is another significant source of industrial chemical pollution in the ocean. This includes the construction, repair, and scrapping of vessels, as well as the transportation of cargo and other materials across the ocean. The University of Plymouth found that ropes used in the maritime industry could be responsible for releasing large amounts of microplastics into the ocean.

In addition to plastic and industrial chemicals, other ocean pollutants include nutrients from fertiliser runoff, light, and noise. These pollutants can have detrimental effects on marine life and ecosystems, highlighting the importance of addressing and mitigating ocean pollution.

To reduce industrial chemical pollution in the ocean, it is crucial to implement measures that prevent the release of chemicals into the environment. This includes improving waste management practices, regulating the use and disposal of chemicals, and promoting sustainable alternatives to harmful chemicals. By addressing the sources of industrial chemical pollution, we can help protect the health and biodiversity of our oceans.

Land-based sources

Eighty per cent of marine litter comes from land-based sources, including those far inland. This pollution can enter the ocean via storm drains, sewers, and other routes.

One of the biggest sources of ocean pollution is nonpoint source pollution, which occurs as a result of runoff. This includes many small sources, like septic tanks, cars, trucks, and boats, plus larger sources, such as farms, ranches, and forest areas. When large tracts of land are plowed, the exposed soil can erode during rainstorms, carrying agricultural fertilizers and pesticides into the sea.

Another source of ocean pollution is the maritime industry, which includes the construction, repair, and scrapping of vessels, and the transportation of cargo and other materials across the ocean. Ropes used in this industry can be responsible for releasing huge amounts of microplastics into the ocean — up to 760 fragments per meter, according to the University of Plymouth.

Nutrient pollution is another issue, caused when excess nutrients, usually nitrogen and phosphorus, enter bodies of water and act as fertilizers.

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