The archipelago of 17,000 islands is the world's second biggest contributor of plastic pollutants in the oceans, according to government officials.
A fast-growing population and a coastline with many cities has created a "perfect storm" for trash finding its way into the surrounding seas, according to green groups, with garbage collection and recycling failing to keep pace with development.
"Youths can drive bigger and faster changes," said Swietenia Puspa Lestari, 24, an environmental engineer who co-founded the Indonesian youth-led non-government organization Divers Clean Action (DCA) in 2015.
"They have no hidden agenda and only care about the future," she told the Thomson Reuters Foundation by phone from Jakarta having been inspired by teenage activist Greta Thunberg's angry speech at the UN last month.
Lestari, a keen scuba diver, helped to set up DCA when she was a student at Bandung Institute of Technology and the group now has about 1,500 volunteers in Indonesia and across Southeast Asia, working with communities and organizing youth workshops.
DCA also initiated the #NoStrawMovement online campaign in 2017 to ban single-use plastics, which was taken up by hundreds of restaurants, and the group teamed up with fashion giant H&M to collect marine debris for recycling and use in some clothes.
Lestari is increasingly being recognized for her work, listed as one of the BBC's 100 inspiring and influential women for 2019 and taking part in Norway this week in a youth leadership summit run by non-profit Sustainable Ocean Alliance.
But to make progress Lestari said it was critical that local and not just national leaders get more involved to tackle the growing problem of waste — and often it was young people who had the solutions.
The rubbish problem on the resort island of Bali was so bad two years ago that officials declared a "garbage emergency", while Jakarta pledged up to US$1 billion (1.53 trillion kyats) a year to reduce marine plastic debris by 70 percent by 2025.
This national action plan encouraged local governments to find solutions for their areas and regions, and this opportunity should be seized on, Lestari said.
"For the national government, they need to invest in more recycling facilities on islands other than Java because many of our volunteers collect waste but … it is too costly to transport their waste to Java," she added.
The DCA started out by working with communities and businesses on a chain of islands in Kepulauan Seribu, known as Thousand Islands, by the coast of the capital Jakarta.
But the group now works with and educates communities in most provinces across the archipelago about good waste management, conducts clean-ups, and works with businesses and authorities to tackle marine waste and promote recycling.
As well as teaming up with universities on research projects, DCA volunteers give talks at schools, arrange recycling collections, and promote reusable cutlery and food containers.
"Indonesia's youth movement is already there but it needs more room to collaborate with local governments … sometimes they are seen as not knowing anything and just told to go back to their schools," said Lestari.