Fishkill in Pangasinan

22-25 June

Millions of bangus (milkfish) died in Caquiputan Channel in the towns of Anda and Bolinao in Pangasinan due to sudden change in temperature. News report says, according to the Bureau of Fisheries and Aquatic Resources (BFAR), that because of sudden change in temperature, the dissolved oxygen (DO) level dropped to 1.7 parts per million (ppm) at surface, and about 2 to 3 ppm at the middle depth.

According to Dr. Westly Rosario, interim executive director of BFAR’s National Integrated Fisheries Technology, as cited in news report, the normal level of DO for bangus growth is 5.0 ppm.

“Rosario said the long rains after hot days prior to the problem could have lowered water salinity and caused the death of micro algae” (Philippine Star). Micro algae helps in production of hydrogen and oxygen.

Aside from that, there also occurred a neap tide wherein no tidal action occurs, thus, according to Rosario, “there is no mechanical aeration of the water” aggravating the situation.

An estimated P50 million worth of bangus is lost in Bolinao town alone. The estimated losses in Anda and Dagupan, another town affected by fish kill, are not yet available.

Sources: bomboradyo.com, The Philippine Star, Philippine News Agency