By Jojo Rinoza
Dagupan City, Pangasinan — An aquaculture specialist has warned “bangus” growers in the city to monitor the water in their fishponds, noting how some have already suffered “gataw” – an event when the milkfish surfaces to gasp for air – or, worse, a “fish kill.”
Dr. Wesley Rosario of the Bureau of Fisheries and Aquatic Resources-National Integrated Fisheries Development Center (BFAR-NIFDC) explained that “during the transition from the dry season to the rainy season, fishponds experience abnormalities and these usually lead to fish kill.”
Dagupan City has experienced rainfall almost daily in the afternoon the past week and this has caused changes in the salinity of the fishponds, said Rosario.
“Kapag immediately tumabang ang tubig, namamatay ang mga natural food ng isda,” he said. The abnormality happens when the salinity abruptly changes and the plankton, moss, algae and other water plants die. “These are the oxygen producers in the water,” Rosario said.
“Nawawalan ng oxygen ang isda na nagreresulta sa fish kill (Fish lose oxygen and this result in fish kill),” he added.
Locals call this event as “tangok,” or oxygen starvation leading to fish stress or kill.