This article was created in partnership with the National Geographic Society.

A dead sperm whale that washed ashore in eastern Indonesia had consumed a horrifying collection of plastic trash, including 115 drinking cups, 25 plastic bags, plastic bottles, two flip-flops and a bag containing more than 1,000 pieces of string.

In all, the plastic contents of the whale’s stomach weighed 13.2 pound (six kilograms).

The rotting carcass of the 31-foot (9.5-meter) whale was found Monday in shallow waters just off Kapota Island in the Wakatobi National Park, according to news reports.

“Although we have not been able to deduce the cause of death, the facts that we see are truly awful,” Dwi Suprati, a marine conservation coordinator at World Wildlife Fund Indonesia told the Associated Press.

Sperm whales normally feed mostly on giant squid, supplemented with octopus, fish, shrimp, crab, and small sharks. They are found throughout all the world’s oceans and are listed as endangered under the Endangered Species Act and considered depleted under the Marine Mammal Protection Act.

Indonesia, with a population of 263 million people and 34,000 miles (54,716 kilometers) of coastline, ranked second, behind China, on a list of the top 20 worst polluters of plastic trash to the world’s ocean, according to a 2015 study that found 192 coastal countries contribute a combined total of 8.5 million tons of plastic waste to the oceans every year.

Earlier this year, China stopped buying plastic scrap from the rest of the world, disrupting the global recycling industry and shifting the world’s plastic waste crisis to Southeast Asia. (Read more about that here.)

Luhut Binsar Pandjaitan, Indonesia’s minister of maritime affairs, told the Associated Press that discovery of the whale should help raise awareness about plastic waste and the need to reduce its use. He said the government aims to reduce Indonesia’s plastic use by 70 percent by 2025. He said the government has urged shops to stop providing plastic bags to customers, and has begun an educational program in schools to educate children about the problems of plastic waste.

“I’m so sad to hear this,” he told the Guardian. “It is possible that many other marine animals are contaminated with plastic waste and this is very dangerous for our lives.”

The grim discovery was the second whale to wash ashore with a stomach full of plastic in recent months. Last June, a dying pilot whale was found in the southern province of Songkhla near the Malaysian border. Rescuers worked for five days to revive the mammal, but did not succeed. Just before the whale died, it spit out five plastic bags. An autopsy found another 80 bags and other pieces of plastic trash in the whale’s stomach weighing 17 pounds (eight kilograms).

17 Pounds of Plastic Waste Kills Pilot Whale

National Geographic is committed to reducing plastics pollution. Learn more about our non-profit activities at natgeo.org/plastics. This story is part of Planet or Plastic?—our multiyear effort to raise awareness about the global plastic waste crisis. Learn what you can do to reduce your own single-use plastics, and take your pledge.