Jelebu: Excessive algae growth amid prolonged hot weather and a lack of rainfall has caused the river water in Mukim Pertang, Jelebu, to turn green, according to the Negeri Sembilan Department of Fisheries (DOF).

According to BERNAMA News Agency, the director of the Negeri Sembilan DOF, Kasim Tawe, stated that investigations revealed the change in water color was not due to pollution, but rather the result of green algae growth in nearby fish ponds brought on by the persistent hot weather.

Kasim Tawe emphasized that the DOF has initiated monitoring efforts in the area, as algae growth in fish ponds can have varying effects on fish, depending on the algae's density and the species of fish present. Under controlled conditions, algae can be beneficial, providing dissolved oxygen, serving as a natural food source, and improving water quality.

Kasim also highlighted the positive role of algae as a natural shield against the sun's rays, which helps reduce stress on fish. However, he warned that if algae growth becomes uncontrolled, it could lead to a rapid decline in dissolved oxygen levels, especially at night, and cause sudden fluctuations in water pH. Such conditions could result in clogged gills in fish.

To manage algae growth, fish breeders are advised to employ measures such as using waterwheels at night, gradually changing the water, reducing feeding, installing shading nets, applying beneficial bacteria (probiotics), and reducing the fish population in ponds.

The Jelebu District Fisheries Office, along with the Pertang Police Station, will continue monitoring the river and fish ponds to maintain control over the situation. The former mining pond, used for breeding baung, red tilapia, and Lee Koh fish, spans approximately 29.54 hectares.

This development follows earlier concerns raised by a viral screenshot of a WhatsApp message, which speculated that the river's color change was caused by water discharge from nearby fish-breeding ponds.