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View all search resultsJakarta declares war on janitor fish as population explodes
The fish, locally known as ‘ikan sapu-sapu’, survive better in polluted waters compared to other fish, making them a dominant species in heavily contaminated rivers across Jakarta.
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Two men carry captured janitor fish on April 17, 2026, in nets during a Ciliwung River cleanup operation in Cililitan, East Jakarta. The Jakarta provincial administration declared war on the invasive fish, which thrives in heavy-polluted rivers across the city. (Antara/Sulthony Hasanuddin)
J
akarta has been waging a war against janitor fish infestations that have taken over the city’s rivers and damaged its ecosystems, as the capital struggles to restore biodiversity to its polluted waterways.
The provincial administration has launched operations to catch the fish, locally known as “ikan sapu-sapu”, since April 17 workers were deployed to numerous waterways across five municipalities in the city, catching and killing nearly 70,000 of the fish and weighing about 7 tonnes.
The caught fish were later buried.
The battle against the infestation continued on April 20 in East Jakarta, where hundreds of city-employed sanitary workers and local officials took part in a second clean-up operation in the Ciliwung, Sunter and Cipinang rivers that flow through the municipality.
In less than an hour, they caught two sacks full of the fish, said Pondok Bambu subdistrict head Ateng Surahman on the sidelines of the cleanup.
“We are catching these fish again because their population is still dense in this area,” Ateng said. “They ruin the river embankment by aggressively digging holes.”
As of Thursday, joint authorities had caught around 10 tonnes of janitor fish across the city, according to the city’s Maritime, Fisheries and Food Security Agency.
