: Title: Jakarta Faces Environmental Crisis as Hundreds of Thousands of Invasive Sucker Fish Flood Waterways, Sparking Public Health and Economic Concerns

South Jakarta authorities have intensified efforts to remove invasive “janitor fish” from local waterways, targeting up to 10 tons of the suckermouth catfish to protect native species and address public health concerns.

The operation, led by South Jakarta Mayor Muhammad Anwar, involves Public Infrastructure and Facilities Handling (PPSU) workers conducting clean-up sweeps in areas such as Setu Babakan in Jagakarsa. On Friday, April 17, 2026, teams targeted around 5 tons of the fish, following a previous effort that removed approximately 5.3 tons, bringing the cumulative total close to the 10-ton goal.

All fish collected during the operation were confirmed to be already dead before burial, addressing concerns over proper handling and ethical treatment. The procedures follow recommendations from the Indonesian Ulema Council (MUI) to prevent public misunderstanding and ensure respectful disposal.

Mayor Anwar emphasized that the initiative is being carried out in accordance with MUI’s advice, stating, “To prevent any confusion going forward, we are carrying out this process in accordance with MUI’s advice. Today’s operation has gone well.”

The janitor fish, locally known as ikan sapu-sapu, are recognized as an invasive species originating from South America’s Amazon and Paraguay River basins. They were introduced to Indonesia through the ornamental aquarium trade and have since proliferated in Jakarta’s nutrient-rich rivers, canals, and reservoirs, where the lack of natural predators allows them to thrive.

Authorities warn that the fish pose a significant threat to native aquatic ecosystems by outcompeting local species for resources and altering environmental balance. The Jakarta Provincial Government has escalated its campaign in response to growing scientific consensus on the ecological and economic risks posed by the suckermouth catfish.

In addition to environmental concerns, the fish have entered local food supply chains through informal markets, where they are sometimes processed into products such as nuggets, otak-otak, cilok, crackers, and siomay—a practice described as medically contentious but widely acknowledged in certain communities.

Meanwhile, some residents, particularly along the Ciliwung River in Kalibata, rely on catching janitor fish as a source of livelihood. Fishermen like Ajum, 39, report earning between Rp15,000 to Rp18,000 per kilogram (approximately US$0.88 to US$1.06 at an exchange rate of US$1 = Rp17,000), though catches vary widely depending on water conditions and safety risks during floods.

The dual reality of the janitor fish—as both an ecological threat and a source of income for some—has created a complex dilemma for Jakarta officials, who must balance eradication efforts with the socioeconomic impacts on informal fishing communities.

As of April 21, 2026, the removal campaign remains ongoing, with joint teams continuing sweeps across affected waterways to meet the 10-ton target and restore ecological stability in Jakarta’s aquatic environments.