Ocean Sentry
(From visayandailystar.com)- Overcrowded operations of fish pens along the river of Brgys. Saraet and Aguisan in Himamaylan City affected its water quality and resulted in low dissolved oxygen levels, leading to a massive fishkill in the area, findings of the Bureau of Fisheries and Aquatic Resources 6 show. Regional Director Drusila Esther Bayate said yesterday the findings were based on the investigation of the BFAR 6 on October 13 and 14, after their office received reports of the series of fish kill incidents.
Bayate said there are about 150 operators of fish pens for milkfish and grouper, and fish traps along the six- to seven-kilometer stretch of the river.
At present, she said both banks are occupied by fish pens and traps, leaving only a 50-meter clearance in the 150-wide river.
“In theory, a certain body of water has only a 10 percent carrying capacity for mariculture,” Bayate said.
BFAR-Negros Occidental Director Carlito Delfin had earlier said that tests of the Analytical and Diagnostic Laboratory of the Negros Prawn Producers Marketing Cooperative Inc. showed that some portions of the river had zero oxygen level while in others, only 4.8 ppm (parts per million).
Delfin said that for fish to survive, the dissolved oxygen level should not have been less than 5 ppm. Below 5 ppm means there is very little aquatic life, and levels that remain below 1 to 2 ppm for a few hours can result in large fish kills.
Earlier reports said that 70 tons to 200 tons of dead milkfish have surfaced in the river.
(By NANETTE GUADALQUIVER)
