When a small company sought a licence to dispose of waste on the island of Teshima, the local government was happy to say yes. Job creation and waste disposal were always a problem on the hundreds of islands dotted across Japan’s Inland Sea.

The company, Teshima General Tourist Development, was duly given permission to handle sludge and wood waste on the tiny island, which has a population of just 1,000. Five years later, in 1983, that licence was expanded to include metal waste.

For more than a decade, as Japan’s economy boomed in the 1970s and 1980s, the company continued to operate quietly on the western tip of the island. Then in 1990, the local community was shocked by a raid from the police in distant Hyogo prefecture.

The company, it turned out, was importing tonnes of toxic waste from across the west of Japan, including Hyogo, and dumping it on the island. “Basically, the waste came from across the Kansai area, including oil, shredded cars and chemical byproducts,” says Kunihiko Saegusa, mayor of Tonosho, a town on a nearby island, whose administrative boundaries include Teshima.

The case of Teshima highlights a broader problem for the Japanese archipelago. Among more than 6,000 islands, there are many with populations of just a few hundred. These islands are remote and fragile ecosystems. Yet at the same time, they must provide sustainable water, electricity, transport and waste disposal.

With the population on many islands in decline, it is becoming ever harder to invest in sustainable local services. Some islands are also popular tourist destinations, which creates further problems of sustainability, and they are directly affected by plastic waste dumped in the ocean.