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Combatting the Plastic Tide: Microplastics, Seabirds, and Japan’s New Plastic Recycling Law

Craig Thomas Donovan


  • Explores how seabirds in Japan are increasingly interacting with plastic waste in Japan’s marine environment.
  • Discusses how microplastics and other plastic debris adversely affect seabirds.
  • Describes the three main components of Japan’s Plastic Resource Circulation Strategy.
Combatting the Plastic Tide: Microplastics, Seabirds, and Japan’s New Plastic Recycling Law
Halfdark via Getty Images

The expansive range of Japan’s archipelago with its craggy coastline and surrounding nutrient-rich marine areas provides a home for many diverse seabirds from the northern and southern hemispheres. Approximately one-third of the world’s seabirds venture seasonally into Japan’s territorial and exclusive economic zone waters. Seabirds, however, are increasingly interacting with plastic waste in Japan’s marine environment. Significant amounts of plastic waste have accumulated around the northern Tohoku and Kyushu regions. The Arakawa River, which flows into Tokyo Bay, contains large and small plastic pieces. In Nagasaki Prefecture, strong ocean currents deposit plastic refuse on the Tsushima archipelago’s shoreline. Japanese school children remove plastic debris washed up on Awashima and other islands’ beaches in the Sea of Japan. Plastic waste has accumulated on distant Ryukyu Islands like Iriomote Island in Okinawa Prefecture.

A 2018 UN Environment Programme report on plastic pollution lists Japan as the second highest producer of single-use plastics per capita worldwide after the United States. Plastic waste from Japan (and other East and Southeast Asian nations and the U.S. west coast) has accumulated into large, belt-like areas in the northern Pacific Ocean. Approximately 30,000 to 50,000 tons of plastic waste are collected from Japan’s coastline annually. From 1988 to 2016, Japan had the third highest rate of global plastic waste exports, with 70 percent of its exports transported to China.

Most large-sized marine plastic waste does not biodegrade but instead breaks apart into smaller plastic pieces called microplastics. Microplastics negatively impact the marine environment, seabirds, and other organisms. Approximately one-half of all seabird species have experienced population declines, with one-third of species threatened with extinction worldwide by marine plastic pollution as one of the main causes.Recent scientific research also shows that seabird species, like shearwaters that migrate to Japan seasonally, are becoming contaminated by toxic chemicals found within and adsorbed to microplastics and other marine plastic debris.

To reduce Japan’s global plastic footprint, the Japanese government has recently enacted the Act on the Promotion of Resource Circulation for Plastics (Purasuchikku ni kakaru shigen junkan no sokushin-tō ni kansuru hōritsu) (hereinafter referred to as the Plastic Resource Circulation Act or PRCA). This article discusses marine microplastic pollution’s impacts on the world’s seabirds, including two shearwater species that migrate to Japan, briefly analyzes some of PRCA’s main provisions, and addresses a significant weakness in the new law. This article concludes with some recommendations to improve PRCA to further protect seabirds and the marine environment.

Microplastics' Impacts on Seabirds

There are two types of marine plastic waste: 1. large, commonly used plastic items or “macroplastics” measuring greater than five millimeters (mm) long that retain their shape when discarded (e.g., PET bottles); and 2. small plastic fragments called “microplastics” measuring less than five mm long. Microplastics constitute most plastic waste in the ocean. “Primary microplastics” include small plastic particles designed for commercial use in cosmetics and toiletries (e.g., scrubbing agents), plastic pellets used as raw material in industrial plastic manufacturing, or fragments produced from the abrasion of plastics during use (e.g., lost fishing gear or synthetic textile fibers shed during laundry). In contrast, “secondary microplastics” constitute small plastic fragments resulting from the breakdown of macroplastics from the sun’s ultraviolet rays and the ocean’s wind and wave action.

Microplastics and other plastic debris adversely affect seabirds. Abandoned, lost, or derelict fishing gear (ALDFG) such as lines and netting, and other plastic waste can entangle seabirds and cause them to become injured, drown or suffocate, and serve as a source of microplastics. Seabirds ingest microplastics through the food chain. Marine invertebrates like zooplankton consume microplastic fragments. Crustaceans, cephalopods, and fish eat the zooplankton and eventually become seabirds’ primary prey. Seabirds may also ingest microplastics directly by mistaking colored plastic pieces as food. Because seabirds cannot digest these plastic pieces, the microplastics accumulate in a bird’s stomach and gastrointestinal tract and may result in bowel blockages, ulcers, and intestinal tears. Moreover, as microplastics build up in a bird’s stomach over time, seabirds eat less food, depriving themselves of vital nutrients leading to starvation and death.

Microplastics also have less visible, nonlethal effects on seabirds. The Flesh-footed Shearwater (Ardenna carneipes), which spends the summer foraging in the Sea of Japan and the North Pacific and then migrates in the autumn to breed on Lord Howe Island, New Zealand, shows these effects. This shearwater population has declined approximately 20 to 29 percent in three generations, with plastic ingestion as one leading cause. The International Union for the Conservation of Nature’s (IUCN) Red List of Threatened Species has designated the Flesh-footed Shearwater as “Near Threatened.” In a 2019 study, scientists found that Flesh-footed Shearwater fledglings have significant health problems from ingesting even a few pieces of microplastics or other plastic debris in their stomachs. Flesh-footed Shearwater adults often mistakenly regurgitate microplastics and feed them to their young. Fledglings that consume these plastics have low blood calcium levels, small body mass, and reduced wing, head, and beak lengths. Plastics in young birds also cause increased amounts of uric acid, cholesterol, and amylase that adversely affect the birds’ kidney function and may lead to other illnesses.

Moreover, microplastics can transmit toxic chemicals to seabirds. Since microplastics are hydrophobic and have a large surface area-to-volume ratio, heavy metals and persistent organic pollutants in the marine environment such as polychlorinated biphenyls (PCBs) and per- and polyfluoroalkyl substances (PFAS), become easily attached to microplastics’ surfaces. When seabirds consume microplastics directly or prey containing microplastics, these chemicals enter the birds’ bloodstream and negatively impact their growth and health.

Seabird contamination also occurs through toxic chemical accumulation in seabird tissues from the leaching of additives found within microplastics. In a joint study published in October 2021, an international team of scientists found plastic additives in the tissues of 52 percent of the world’s seabirds. The scientists analyzed the oily fluid secreted from the preen gland near the tail base of 145 birds from 32 species in 16 different areas worldwide. Seabirds use this fluid to waterproof their feathers. The researchers detected plastic additives in 76 birds and estimated that 10 to 30 percent of the birds analyzed had accumulated plastic additives in their tissues from plastic ingestion. The scientists detected additives in several species, including the Flesh-footed Shearwater and the Streaked Shearwater (Calonectris leucomelas), which breeds and nests mainly on offshore islands of Japan like Awashima Island, Niigata Prefecture, and the Korean Peninsula in the warmer months and then migrates south during the winter. Streaked shearwater populations are also declining and designated as “Near Threatened” on the IUCN Red List.

PRCA’s Enactment

In response to a ban by China and several Southeast Asian nations in 2018 on plastic waste importation, Japan expanded its domestic recycling market. In 2019, the Japanese government implemented the Plastic Resource Circulation Strategy based on the principles of reduce, reuse, recycle (3Rs) plus renewables to develop a circular economy through plastic waste management. About the same time, the government also announced the Action Plan to Counter Marine Plastic Waste.

To accomplish these policy initiatives, the Japanese Diet enacted PRCA, which became effective on April 1, 2022. PRCA aims to protect the environment and encourage the Japanese economy’s growth by requiring government agencies to establish a basic policy that promotes reducing plastic product use, recycling plastic waste by municipalities, and establishing voluntary collection and recycling systems for plastic waste by businesses. Article 1 of PRCA states, “The purpose of this Act is to contribute to the conservation of the living environment and the sound development of the national economy [through] a system of measures to promote the recycling by businesses and voluntary collection of recycled plastics waste products from the municipalities, and the rationalization of plastic-containing products to promote the resource circulation of plastics in response to changes in the environment surrounding plastic-containing product waste in Japan and overseas.” The Minister of Economy, Trade and Industry from the Japanese government’s Ministry of Economy, Trade and Industry (METI) and the Minister of the Environment from the Ministry of the Environment (MOEJ) constitute the “competent ministers” who administer PRCA jointly, with a few exceptions.

PRCA comprises three main components. First, Japan must reduce plastic product use through “green” design, manufacturing, and procurement. The Act authorizes the government to publish design guidelines to encourage designers and manufacturers of plastic-containing products to make products with environmentally friendly designs. The Act also establishes a government certification process for manufacturers whose products meet the design guidelines. Manufacturers seek certification by submitting an application to the government describing the product’s nature, purpose, and design. The government then investigates whether the design conforms to the product design guidelines. If the design conforms, the government grants certification and publicizes the product’s approval. Furthermore, the government will procure preferentially certified plastic-containing products, and manufacturers and consumers also “must make every effort to use certified plastic-containing products.”

Second, the government will establish criteria for retailers and service industries to determine measures to control the discharge of plastic-containing product waste from plastic products (provided free of charge that accompany sales of goods and provision of services) and implement measures for the rationalization of specific plastic-containing products. The Cabinet Order for PRCA's enforcement specifically targets 12 single-use plastic items for reduced use. The items include plastic forks, spoons, table knives, stir sticks (muddlers) and drinking straws used by restaurants, take-out delivery businesses, and other retailers; hairbrushes, combs, toothbrushes, razors, and shower caps used by the accommodation industry like hotels; and hangers and clothing covers by laundry service providers like dry cleaners. Moreover, the government may issue recommendations to suppliers of large amounts of single-use plastics (five tons or more per year) that fail to reduce such products’ use. If a supplier continues not complying with a recommendation, the government may penalize the supplier by disclosing the business’s name to the general public. The government may also issue remedial orders to suppliers for noncompliance with the criteria.

Third, the Act establishes systems to increase plastic collection and recycling by municipalities, manufacturers, retailers, and waste generators. Before PRCA's enactment, most municipalities separated, collected, and recycled plastic containers and packaging and processed other plastic products in cooperation with the public. Municipalities could only recycle plastic containers and packaging and incinerate or discard other plastic products in landfills. Under PRCA, however, municipalities collect and recycle all plastic containers, packaging, and other products. Municipalities will also cooperate with recyclers to develop recycling plans. When the government approves the plan, recyclers may recycle plastics delivered directly to recycling facilities without the municipalities first sorting and storing plastic resources. Municipalities must also formulate standards for separating plastic-containing products. Plastic waste generators within a municipality must comply with these standards when municipalities and government-certified businesses assign responsibilities relating to plastic waste recycling plans to third parties.

Moreover, the Act promotes voluntary collection and recycling by plastic manufacturers and retailers. The Act encourages these businesses to develop and submit collection and recycling plans to the government for review and approval. Once the government approves the plan, certified businesses can recycle plastic waste products without obtaining a government permit. Furthermore, the government will establish standards for waste-generating businesses to reduce and recycle more plastic waste. If a 250 tons or more generator of plastic waste fails to comply with the standards, the competent ministers may issue recommendations or order compliance. The government will also encourage waste generators to formulate recycling business plans and submit them for government approval. Upon approval, waste generators may recycle plastic waste without obtaining a government permit.

Although PRCA's focus on curbing single-use plastic waste, promoting recycling to achieve a circular economy, and reducing Japan's contribution to marine plastic pollution is noble, the new law has some weaknesses. One area for improvement is PRCA’s failure to address the problem of ALDFG, or "ghost gear," in the ocean. Fishing nets, ropes, lines, buoys, and traps, mainly composed of plastics, constitute some of the most harmful plastic waste to seabirds and other marine life and a source of microplastics. The Japanese Diet should amend PRCA to include measures that prevent fishing gear from becoming discarded or lost in the ocean. An amended PRCA could require the Japanese government to establish a ghost gear fund to provide further financial support for deploying fishing vessels and fisheries patrol boats to remove ALDFG from Japanese and international waters. In addition, the government could develop an online, publicly accessible tracking and reporting system for commercial harvesters to mark, and report lost fishing gear for return to individual vessels and nations. A revised PRCA also could incentivize the Japanese fishing industry to recycle ALDFG, promote more microbiological research on plastic-eating microorganisms in the ocean, develop marine biodegradable fishing nets and other equipment, and support and fund strong partnerships between the Japanese government, the fishing industry, nongovernmental organizations, and citizens for prevention and retrieval projects.

The views and conclusions presented are those of the author in his personal capacity and do not necessarily represent the views of the U.S. government, DOI, or its components.