Overstocking blamed for fishkill

BOLINAO, Pangasinan, Philippines—In an aquarium no bigger than a foot-high box, five goldfish will survive without an aerator when their caretaker provides them a pinch of feed twice a day and a regular change of water.

But try putting 20 goldfish in that same aquarium, feed them a cup of feed daily, do not change its water for weeks and turn off its aerator. Then, pour in cold water. Chances are, the goldfish will die.

This was how Dr. Westly Rosario, chief of the National Integrated Fisheries Technology Development Center (NIFTDC) in Dagupan City, explained how “bangus” (milkfish) cultured in pens and cages in the Kakiputan Channel in Bolinao and Anda towns were decimated recently.

Dr. Edgardo Gomez, professor emeritus of the University of the Philippines Marine Science Institute, said: “[The fishkill was the result of] environmental degradation, with the [structures] exceeding the carrying capacity of the water due to heavy fish stocking and excess feeding.”

Rosario said fish cages and pens in the Kakiputan Channel were stocked beyond the carrying capacity of the water. He said a square meter of fish cage there contained 50 pieces of bangus, exceeding the recommended stocking capacity of 25 pieces.

Worse, the tidal flow in the 2.7-km channel had been obstructed by fish traps laid upstream of the Tambac Bay, as well as by fishery structures at the Catubig area leading to the Lingayen Gulf.

Scientists have been warning authorities that fishery structures, which mushroomed along the Kakiputan Channel in the last 10 years, would endanger the marine ecosystem there.

Nestor Domenden, Bureau of Fisheries and Aquatic Resources (BFAR) director in the Ilocos, has asked the public to expect a shortage of bangus in public markets in the next three weeks after the fishkill emptied cages and pens in Anda and Bolinao.

Domenden said the fishkill is expected to reduce by 1.06 percent Ilocos region’s projected bangus production of 141,000 metric tons (MT) this year.

“[This is] not so significant, but if you look at its immediate impact, like in three weeks’ time, there will be a shortage [of bangus] because of the smaller volume of bangus that is now reaching the markets,” Domenden said.

Pangasinan, which is the country’s top bangus producer, supplies 60 percent of milkfish sold in Metro Manila.

Anda and Bolinao lost a combined 563.26 MT of bangus, worth P44.17 million, reports from the provincial agriculture office showed.

Rosario said while bangus production in Bolinao and Anda stopped, supply can come from fish farms in the towns of Sual, Lingayen, Binmaley, Mangaldan and San Fabian, and Dagupan City.

“There was no fishkill in those areas and hopefully, the bangus supply to Metro Manila and other parts of Luzon will continue,” Rosario said.

But bangus growers in other areas in Pangasinan had postponed the harvest of their stocks because of the plummeting retail prices of bangus.

Julie Ann Perez, president of the Malimgas-Aliguas Dagupan Market Vendors’ Federation, said milkfish prices had dropped from P90 to P50 a kilogram, because consumers are afraid to buy bangus for fear that these are contaminated and came from fishkill-hit areas.

Anda Mayor Aldrin Cerdan said a state of calamity has been declared in the fishkill-hit villages of Awag, Siapar and Mal-ong.

“After cleaning our waters of dead fish, we hope we can extend help to the displaced caretakers. But we don’t have much,” Cerdan said.

He said about 400 families in the three villages depend on the fish pens and cages for their livelihood by working as caretakers.

Domenden said his office has linked up with the regional office of the Department of Labor and Employment to devise short-term livelihood projects that may be granted to displaced caretakers.

“We are looking at fish processing, marketing, backyard piggery and others,” Domenden said.

He said he will also conduct an inventory to find out the status of stocks that survived the fishkill.

Rosario said the oxygen level in the fishkill-hit area on Thursday improved to 4.8 parts per million (ppm), from less than 2 ppm several days ago.

“Based on this [figure], the water has recovered a little because the tide has returned to normal,” Rosario said.

He said in some parts of the channel, sludge is a meter deep, while in other sections, 10 inches deep.

Rosario said a sudden downpour would disturb the muck and bring to the surface the polluted water. He said this would again reduce dissolved oxygen level and endanger marine life.

To avoid this, Rosario said the Kakiputan Channel should be cleared of all structures to improve water flow.

In Anda and Bolinao, the disposal of rotting bangus has become a major headache for officials and residents.

Margaret Celeste, a Bolinao resident, said truckloads of bangus that were disallowed by the Dagupan City agriculture office to be sold in the city’s markets recently were dumped in her town.

“The rotting bangus were sent back to Bolinao and the local government had no choice but to dump at Bolinao sanitary landfill,” she said.

Brunner Caranza, the town’s municipal planning and development officer, said the sanitary landfill “is not ready to accept that big volume of dead fish.”

“We are bringing extra equipment to the sanitary landfill for the dumping of dead fish. This also means extra expenses for the local government,” he said.

Stench from the waters off Bolinao and Anda, coming from uncollected rotting fish, has become a source of discomfort for residents.

“I was informed [on Wednesday] that in two days, dead fish from Anda will [flow into] the waters of Bolinao. And this morning (Friday), our part of the channel was really stinking,” Celeste said.

Officials of Bolinao and Anda have appealed to residents to help in cleaning their waters by collecting dead fish and piling them on designated spots along shorelines so these could be collected by trucks.