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Three-fourths of waste in Jakarta’s notoriously polluted rivers is plastic

  • Most of the waste collected from the rivers and holding facilities in Indonesia’s capital, Jakarta, is plastic, new field-based research has found.
  • Researchers note that the plastic debris recovered from the surface water amounted to 9.9 grams, or a third of an ounce, per person on average, which is lower than an estimate from a widely cited 2015 study.
  • The researchers have called for a better mitigation strategy to eliminate plastic pollution in rivers and subsequently the ocean.
  • Indonesia, a country of more than 270 million people, is the No. 2 contributor to global marine plastic pollution, behind only China.

JAKARTA — The Citarum River that skirts the Indonesian capital, Jakarta, is infamous as the most polluted river on Earth. The rivers inside Jakarta aren’t in much better state, either, with a new study showing that most of the waste collected from the city’s rivers is plastic.

Plastic accounted for 74% and 87% of the total human-generated waste found in five rivers and three holding facilities, respectively, in Jakarta between December 2019 and January 2020. That was the finding made by researchers from Indonesia and Japan in a paper published Aug. 13 in the journal Marine Policy. They also calculated that the plastic debris recovered from the surface water amounted to 9.9 grams, or a third of an ounce, per person on average. That’s notably lower than an estimate from a widely cited 2015 study.

“Our research focuses on debris caught by floating cube net booms and trash racks located in rivers near residences,” study co-author Pertiwi Andarani from Diponegoro University told Mongabay in an email. “[M]eanwhile other research[ was] based on field data focused on plastic debris in estuaries.”

Trash clogs up Jakarta’s waterways, constricting them and exacerbating flooding. Image by Jonas Gratzer for Mongabay.

Jakarta, with its population of more than 10 million people, is crisscrossed by 13 rivers that empty out into Jakarta Bay. The city has a waste collection and recycling system, but much of the plastic waste in the country is still mismanaged and ends up in rivers. The city government has installed barriers to prevent plastic making its way into the open ocean.

The new study showed that plastic bags are the most ubiquitous form of plastic waste, followed by PET bottles, food packaging, beverage cups, drinking straws, and Styrofoam containers.

“Jakarta has a relatively good waste management system compared to other cities in Indonesia,” Pertiwi said. She also noted in the paper that the study was conducted when the country implemented a plastic bag pricing mechanism to discourage the use of plastic bags.

Indonesia, a country of more than 270 million people, is the No. 2 contributor to global marine plastic pollution, behind only China. The government plans to spend $1billion to cut 70% of its marine plastic waste by 2025 with strategies including reducing land- and sea-based dumping, promoting behavioral change, reducing plastic production, policy reform, and law enforcement.

In July 2020 the Jakarta city administration also officially banned single-use plastic bags at supermarkets, department stores and traditional markets.

“We think that mitigation of plastic pollution must be implemented [in an] integrated [way],” Pertiwi said. “The regulations already exist, but monitoring and implementation is hard to do.”

Waste, much of it plastic, in the Muara Angke eighborhood of Jakarta. Image by Jonas Gratzer for Mongabay.
Plastic waste piled up along the sea wall in the Gedong Pompa neighborhood of Jakarta. Image by Jonas Gratzer for Mongabay.

Pertiwi said the national government should also design a better waste management system when developing the country’s new capital city in Borneo to protect the rivers there from plastic pollution. Indonesia produces about 6.8 million tons of plastic waste annually, according to a 2017 survey by the Indonesia National Plastic Action Partnership. Only 10% of that waste was recycled in the approximately 1,300 recycling centers operating in the country, while nearly the same amount, about 620,000 tons, wound up in the ocean. The vast majority of plastic waste ends up in landfills.

“The main thing that must be done is to prevent the leakage of plastic waste from land, both upstream and downstream,” Pertiwi said. “Personally, education about the importance of good waste management must be given at an early stage and not just the theory, but also the practice.”

Plastic waste in the ocean negatively affects the marine ecosystem as sea creatures like whales, turtles and fish mistake floating plastic waste for food, swallowing material they can’t digest. The plastic accumulates in their bodies over their lifetime, killing them or working their way up the food chain and eventually circling back to humans.

Citation:

Sari, M. M., Andarani, P., Notodarmojo, S., Harryes, R. K., Nguyen, M. N., Yokota, K., & Inoue, T. (2022). Plastic pollution in the surface water in Jakarta, Indonesia. Marine Pollution Bulletin, 182, 114023. doi:10.1016/j.marpolbul.2022.114023

Basten Gokkon is a senior staff writer for Indonesia at Mongabay. Find him on Twitter @bgokkon.

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