Is the Pleco Fish Truly to Blame for Damaging Jakarta's River Ecosystems?

JAKARTA, KOMPAS.com - Pleco fish community activist Anton states that pleco fish are not the main cause of damage to river ecosystems in Jakarta. According to him, the damage is primarily triggered by water pollution and human activities. Pleco fish are not the primary culprit in the reduction of other fish populations. “If it’s said that plecos damage the ecosystem by preying on other fish or their eggs, that’s not entirely accurate. The main factor is actually environmental pollution,” Anton said when contacted by Kompas.com via WhatsApp on Monday (13/4/2026). In addition, species such as catfish, tilapia, and gourami are heavily caught for consumption, leading to declining populations. “Other fish are weaker. Moreover, they are heavily exploited because they can be consumed or sold. Over time, they dwindle, while plecos survive because they are hardier,” he said. According to Anton, pleco fish have a high ability to adapt to polluted environments. This allows their populations to persist or even increase in urban rivers like those in Jakarta. “Pleco fish certainly impact our aquatic environments because they dig holes for reproduction, which can cause riverbank erosion,” he said. However, he refutes the notion that plecos are destroyers of other fish ecosystems. Anton explains that plecos are not predators of fish eggs as circulating information suggests. Instead, what is damaging the ecosystems in Jakarta’s rivers is the severe pollution that has occurred. “It’s not accurate to say that plecos are the main factor. The primary factor in the damage to canals and rivers is environmental pollution,” Anton stated.