World Ocean Day: How much Single-use plastic is in our oceans?

According to UNESCO, 8-10 million tonnes of plastic are released into the sea yearly. On World Ocean Day, Al Jazeera visualises what that looks like.

About 400 million tonnes of plastic products are produced worldwide every year. About half are used to make single-use items such as shopping bags, cups, and packaging material.

An estimated 8 million to 10 million tonnes of plastics end up in the ocean each year. If flattened to the thickness of a plastic bag, that is enough to cover an area of 11,000 sq km (4,250 sq miles), which is about the size of small countries like Qatar, Jamaica, or the Bahamas.

At this rate, plastic waste could grow to an area bigger than 550,000 sq km (212,000 sq miles) over the course of 50 years—about the size of France, Thailand, or Ukraine.

The United Nations designates June 8 as World Ocean Day to raise awareness about the ocean's importance and promote its sustainable use and protection.

How does plastic end up in the ocean?

Plastics are the most common form of ocean litter, comprising 80% of all marine pollution. Most plastics in the ocean come from improper waste disposal systems that dump rubbish in rivers and streams.

Ships and fishing boats also dump plastics, such as fishing nets and other marine equipment, into the ocean.

In addition to plastic bags and containers, tiny particles known as microplastics enter the ocean. Microplastics, which are less than 5mm (one-fifth of an inch) in length, are a primary environmental concern because they can be ingested by marine life and harm both animals and humans.

While research on the health effects of human consumption of microplastics is limited, some studies have indicated that microplastics can accumulate in organs such as the liver, kidneys and intestines. There are concerns that microplastic particles could lead to inflammation, oxidative stress and cellular damage.

“These little particles in the ocean were breaking into little pieces and being consumed by the wildlife living there at an almost unimaginable scale. The main problem is that pieces of plastic contain toxic chemicals, which are already known to interfere with human and animal hormones. They may cause the accumulation of toxins in the body that may lead to ill effects over time,” science writer and author Erica Cirino told Al Jazeera’s The Stream programme.

Which countries are the source of the most plastic in the ocean?

According to a 2021 study published by Science Advances research, 80 per cent of all plastics found in the ocean come from Asia.

The Philippines is believed to be the source of more than a third (36.4 per cent) of all plastic waste in the ocean, followed by India (12.9 per cent), Malaysia (7.5 per cent), China (7.2 per cent), and Indonesia (5.8 per cent).

These amounts do not include waste exported overseas that may be at higher risk of entering the ocean.

What makes plastics so dangerous for the environment?

Plastics are synthetic materials made from polymers, which are long chains of molecules. These polymers are typically derived from petroleum or natural gas.

The main problem with plastics is that they do not readily biodegrade, which means they can persist in the environment for hundreds of years, causing serious pollution problems.

Plastics that find their way into the ocean float on the surface for a long time. Eventually, they sink to the bottom and get buried in the seafloor.

Plastic on the ocean's surface represents 1% of its total plastics. The other 99% are microplastic fragments far below the surface.