Marine plastics are already changing marine biodiversity

It is said that 30 million tons of plastic waste are currently floating in the oceans, and alarms have been sounding off about the impact on ecosystems.

Last December, the Smithsonian Environmental Research Center reported that plastic accumulates with coastal organisms in the open ocean, forming a new “neopelagic” living area.

Plastics expand the habitat of coastal organisms

There are at least five plastic-contaminated gyres, called “garbage patches,” in the world. Particularly, in the area where the most plastic is floating in the North Pacific Subtropical Gyre between California and Hawaii, it is estimated that 79,000 tons of plastic are floating in an area of over 610,000 square miles.

It was discovered that many coastal organisms survive and thrive on marine plastics, including anemones, hydrozoans, and amphipods such as shrimp from plastics collected from the North Pacific Subtropical Gyre by Ocean Voyages Institute founder Mary Crowley and her team. The following is a summary of the results. The fact that communities of coastal organisms that were thought to have difficulty surviving in the open ocean were found to be forming, and that plastics provided habitat, was a major discovery.

Expected ecosystem disturbances as coastal habitats expand

However, the spread of coastal habitats is expected to cause disturbance of open ocean ecosystems and threats from non-native species.

Fortunately, no new species are known to have colonized the West Coast directly, but from the tsunami that hit Japan on Mar. 11, 2011, it was reported that about 300 species of coastal organisms drifted on the coasts of Hawaii and the west coast of the USA from Japan, attached to tsunami debris, ranging from small pieces of plastic to fishing boats and docks.

Scientists estimate that the cumulative amount of plastic waste in the world will overshoot 25 billion tons by 2050, and the ‘garbage patch’ is likely to expand further with this. We’d also expect more plastic will be pushed out to sea as climate change brings more intense and more frequent storms.

Japan needs to be involved in global plastic reduction

As a country facing the Pacific Ocean, Japan should respond to the problem pointed out by this report, through waste management and, more importantly, plastic reduction.

According to an OECD survey, plastics account for 3.4% of global greenhouse gas emissions and need to be reduced not only from a marine litter perspective but also from a climate change one. Currently, more than 120 countries have banned or taxed the use of single-use plastics, mostly limited to plastic bags, which account for only 0.3% of the plastic waste washed ashore in Japan’s case.

Japan enforced the “Act on Promotion of Resource Recycling for Plastics” earlier last month on Apr. 1. Businesses, such as convenience stores, restaurants, accommodation facilities, and dry cleaners, are obliged to reduce waste emissions of products using specific plastics such as forks, spoons, knives, and straws. With this law as a catalyst, Japan must now actively face the problem of reducing plastic.

In addition, Japan needs to support low- and middle-income countries in order to reduce plastic production or increase recycling rates globally. In addition to developing environmentally friendly alternatives, more countries should introduce landfill and incineration taxes, and international development assistance is needed to improve waste management infrastructure in low- and middle-income countries.