BRIN assures that janitor fish burial method does not contaminate soil

Jakarta (ANTARA) - Triyanto, a researcher from the Centre for Limnology and Water Resources Research at the National Research and Innovation Agency (BRIN), stated that controlling janitor fish through capture and burial will not contaminate the soil as long as it is carried out according to procedure. “The metals are in the body, and once buried, as long as they are not exposed to oxidation processes again and do not leach out through water runoff, they will be collected in the surrounding area, because the burial is in a somewhat deep medium, 1-2 metres,” he said in Jakarta on Thursday. He explained that the heavy metals contained in the janitor fish’s body are obtained due to its natural omnivorous nature, which includes absorbing heavy metals. He revealed that these heavy metals do not exit through excretion in the form of faeces, but instead enter the liver through the digestive tract and then become part of the flesh because proteins bind to the heavy metals. “These heavy metals have bioaccumulative properties; they do not decrease. But since they have been moved to clean water, the content will not increase. So, as long as they are controlled in clean water, the absorbed heavy metals remain there,” he said. According to him, various other approaches to controlling the janitor fish population, such as introducing natural enemies like arapaima and piranha fish, could potentially cause new problems in the future. “Instead, what is important is how we improve water quality conditions, with no pollution, allowing local fish to grow and natural predation to occur. So, fish like baung and snakehead can thrive,” he said. He explained the importance of natural predators that the community must preserve. “In the Ciliwung River, there used to be large turtles, but now they are no longer found. If possible, we should reintroduce natural predators like monitor lizards and otters, so they are not caught by the community; they must remain to naturally control (the janitor fish population),” Triyanto concluded.