With 8.8 million tons of plastic waste dumped into the ocean every year, there are few, if any, corners of our oceans free of pollutants. The impact of these pollutants on marine life and ecosystems is tremendous.
Over 50 percent of all plastic waste in the oceans comes from five countries — China, Indonesia, Philippines, Thailand and Vietnam, according to the World Wildlife Fund for Nature (WWF).
In fact, if 20 of the highest polluting countries in the world halve the amount of mismanaged waste, the flow of plastic into the ocean could go down by almost 40 percent.
In 2006, Greenpeace conducted a survey of the world’s coastlines; they found Indonesia recorded the highest levels of marine debris – 29,100 items per kilometer. In highly populated areas of the country, litter covered 90 percent of the beach.
Land-based activities – improperly managed agricultural run-offs and untreated sewage, for example – accounts for over 80 percent of the plastic pollution in our oceans, according to the Ocean Conservancy. Less than 20 percent of the total is from marine sources – fisheries and ships.
Did you know the Pacific and Atlantic oceans have two major garbage patches each? There is even a southern Indian Ocean patch – halfway between Africa and Australia. These patches are huge zones in oceans where garbage accumulates and floats freely in circular motions.
The largest such garbage patch – the Great Pacific Garbage Patch – consists of 80,000 metric tons of plastic trash. This includes abandoned fishing gear, plastic bottles, ropes, baskets, plastic packaging, etc. This works out to 250 pieces of debris for every person in the world.
In fact, there is 180 times more plastic waste than marine life in this garbage patch. The Center for Biological Diversity (CBD) claims marine creatures consume up to 24,000 tons of plastic annually.
Unfortunately, because plastic waste has a low density, it is easily transported across vast distances on the water. The CBD claims not even a single square mile of ocean surface is free from plastic pollutants.
Large pieces of plastic pollutants are bad enough. But microplastics pose a challenge in cleaning up the world’s oceans. Microplastics are tiny fragments of large plastic pieces – usually smaller than 0.19 inches (five millimeters) – and are often mistaken by marine creatures for food.
Worse still, chemicals present in these plastics can get transferred up the food chain to human beings. The feeding animal absorbs the chemicals through the process of bio-accumulation, and once it becomes prey to a larger predator, the contaminants pass on, going up the food chain.
The fishing industry contributes 10 percent of the overall plastic debris, as per a WWF report. These are usually in the form of nets and other fishing gear. "Ghost nets" is the term used to describe fishing nets that are lost at sea or discarded and continue to strangle and trap marine animals for decades.
According to a 2015 study by researchers at Plymouth University, over 700 marine species have encountered man-made debris like plastic and glass. Of these, 17 percent are on the IUCN Red List of Threatened Species.
Research shows that fish and other marine creatures do eat plastics, often confusing them for jellyfish. This irritates their digestive system. If the plastic is not excreted out of the animal, it makes them feel “full” and can lead to their starvation.
Seals are curious and are often seen playing with fragments of plastic debris like netting, catching their necks in the webbing. The seals caught in the plastic harness eventually die because of starvation or wounds caused by the webbing. In the 1970s, scientists at the National Marine Mammal Laboratory concluded that plastic entanglement was killing up to 40,000 seals a year.
Plastic consumption by fish has been linked to physiological stress, liver cancer and endocrine dysfunction due to the chemicals and additives present in the ingested (and transferred) plastic. A 2013 study published in Scientific Reports journal indicates that ingesting plastics can also affect fertility in female fish and development of reproductive tissue in male fish.
Whale sharks filter feed — they gulp a large amount of water and then filter it at the entrance of their throat — near the surface of the water, where plastic floats. According to the Marine Megafauna Foundation, whale sharks can ingest approximately 170 plastic pieces per day.
A 2015 University of Queensland study published in the Global Change Biology journal reveals that 52 percent of sea turtles have eaten plastic pollutants. Debris ingestion can cause death in sea turtles through blockage of the intestines or piercing of the intestinal wall or by absorption of the chemicals in plastic.
According to a study published in the Proceedings of the National Academy of Sciences of the United States of America, seabirds are at a very high risk of ingesting plastic. By 2050, nearly 99 percent of all seabird species like gulls and albatross will have consumed plastic.
The ARC Centre of Excellence in Coral Reef Studies in a 2015 research pointed out that the common corals in the Great Barrier Reef are consuming microplastics since they are present in the seawater.
On June 1, 2018, a male whale pilot died in Thailand after consuming plastic. Autopsy revealed that the creature had about 80 plastic bags weighing up to 18 lbs (8 kg) in its stomach. A sperm whale was found washed ashore dead in February 2018 on the Murcian coast in Spain after ingesting 64 lbs (29 kg) of plastic waste. In the same month, the death of a Cuvier’s beaked whale was reported in Norway after more than 30 plastic bags clogged its stomach. The plastic also led to the malnutrition of the whale.
A 2017 report from Britain’s Government Office for Science estimates that plastic pollution will see a three-fold increase between 2015 to 2025. Since commonly used plastics are durable and non-biodegradable, the U.S. Environmental Protection Agency (EPA) believes that “every bit of plastic ever made still exists.”
