Workers from the Jakarta Environmental Agency recently removed more than 200 suckermouth catfish from the Ciliwung River during a two-hour operation on Thursday (Apr 30) morning. The effort took place in milky-brown, neck-deep water along rubbish-strewn banks, drawing cheers from approximately two dozen local residents.
An Invasive Dominance
The fish, belonging to the Pterygoplichthys genus, are not native to the region; they originate from the tropical waters of South America. In Indonesia, they are known as sapu-sapu, which means broom, whereas they are referred to as janitor fish in other Southeast Asian countries.
These bottom feeders have become the dominant and in some cases the only, species inhabiting Jakarta’s polluted canals, reservoirs, lakes, and rivers.
Impact on Local Biodiversity
The proliferation of the suckermouth catfish has led to a sharp reduction in native fish populations. Species such as the striped snakehead, spotted barb, and Asian redtail catfish have seen their numbers dwindle as the invasive fish take over.
Local resident Baharuddin, 69, noted that it was once easy to find various types of fish in the area. He stated that while the presence of sapu-sapu was first noticed in the 1980s, this specific part of the river is now 100 per cent sapu-sapu.
Potential Future Scenarios
If the suckermouth catfish continue to dominate these waterways, native species like the spotted barb and Asian redtail catfish could face further population declines.
Depending on the frequency of removal efforts by the Jakarta Environmental Agency, the balance of species in the Ciliwung River may shift, though the high level of pollution could continue to favor the invasive Pterygoplichthys genus.
Frequently Asked Questions
What is the suckermouth catfish called in Indonesia?
In Indonesia, the fish is known as sapu-sapu, which translates to broom.
Where did the suckermouth catfish originate?
These fish are native to the tropical waters of South America.
Which native fish species have been affected by this invasion?
The populations of the striped snakehead, spotted barb, and Asian redtail catfish have been sharply reduced.
Do you believe urban river restoration can successfully bring back native wildlife once an invasive species has taken over?
