Unregulated Fish Pen and Cage Operations Mess Up Coastal Ecosystems
by ALECKS P. PABICO
BOLINAO, Pangasinan—The scene that greeted the residents of this northern Luzon seaside town one morning last February seemed straight out of the pages of the Bible's Old Testament. Overnight, the coastal waters had turned red and murky, resembling a vast pool of contaminated blood. Evoking images of the first of ten plagues that Moses had cast upon Egypt, tons of dead fish were soon floating on the red waters. In the next couple of days, the sea breeze would reek of nothing but the stench of decomposing fish as the tide swept them back to shore.
Another fish kill, smaller in scale, but still devastating for the town residents, would hit Bolinao two months later. This May, it was the turn of Dagupan City, Lingayen and Binmaley to suffer the "curse" of the dead fish.
The spreading curse, however, does not have biblical or divine origins. Indeed, the massive fish kills some coastal Pangasinan towns have been witnessing can be traced back to the irresponsible and unregulated practices in bangus (milkfish) culture that have been pursued relentlessly in the Lingayen Gulf since 1995.
What has often characterized the bulk of such activities are overcrowded fish pens and cages concentrated in the coastal and inland waters of Bolinao, Dagupan and Binmaley in Pangasinan, and in Aringay in La Union. Marine scientists and environmentalists now say that other waters cluttered with fish pens and cages, such as those in Capiz, Iloilo, Negros Oriental and Cebu in the Visayas, could well expect similar fish kills if they do not act soon.
The scientists and environmentalists add that such fish kills only further threaten the viability of fisheries in the Philippines, and especially so in the aquaculture sector that is seen to provide an alternative means to meet the protein demands of Filipinos. The tons of dead fish are also signs of deteriorating ecosystems in general and water quality conditions in particular. Yet even the government remains adamant in emphasizing aquaculture, or the growing of fish in fresh, brackish and marine areas using ponds, pens and cages, to the detriment of other fisheries sectors.
What is happening, say experts, is that the proliferation of fish pens and cages has led to depleted oxygen concentration and the rise in harmful algal bloom in the host waters.
"Sure, the argument is that we have had this thing (fish kill) in Bolinao and other places before," says Dr. Gil Jacinto, director of the Marine Science Institute of the University of the Philippines (UPMSI). "Yes, there's a natural process but what we've done is really affect the system, perturbed it too much."
Jacinto and other experts explain that the congestion of fish pens and cages—which is almost always way beyond the water's carrying capacity—has come with a host of attendant problems, including overstocking, excessive feeding and pollution. All these contribute to the high load of nutrients.
"If there is an excessive load, the feeds that don't get broken down or re-mobilized continue to be broken down by the microorganisms, the phytoplanktons and zooplanktons," says Jacinto, whose institute maintains a laboratory just a few meters from where fish pens and cages choke the coastal waters of the Caquiputan Channel here.
"And when they do that, they consume oxygen. So they cause the depletion of the oxygen level in the sediment-water column surface."
The experts say they had not been remiss in warning people, Bolinao residents included, of the dangers of having too many fish pens and cages. But few heeded their warnings, most probably because the fish pen owners were powerful individuals who were too busy reeling in the huge profits brought by their operations.
"(We) can only provide our advice," says Dr. Porfirio Aliño of the UPMSI, when asked if they had told Bolinao residents what could happen. "But those who should be implementing the ordinance are the fish pen owners, they know. And we've been giving them seminars, asked them to participate in the monitoring programs. And in fact, we told them since 1997, sobra na 'yung ginagawa ninyo (you've overshot the limit)."
Aquaculture through semi-intensive milkfish fishponds started in the Lingayen Gulf in the early 1970s, then peaked in the 1980s with the rampant conversion of mangrove areas into fishponds. With the ban in mangrove cutting enforced in 1995, bangus culture eventually expanded into the coastal waters and rivers.
Prior to the massive February fish kill, there were around 1,170 units of fish pens and cages in Bolinao alone. This was more than double the allowable limit of 544 units, which is the maximum carrying capacity of the channel as determined by its own municipal fisheries ordinance.
Strangely enough, Bolinao is unique among local government units within the Lingayen Gulf as the only municipality to have passed a fisheries ordinance and adopted a coastal development plan anchored on resource management. But even that did not seem to have provided enough guarantees for the regulation of fish pen and cage operations there.
"We could say that there is still a human error in the enforcement of their law, and this is acknowledged by the local chief executive," says Nestor Domenden, director of the Bureau of Fisheries and Aquatic Resources (BFAR) in Region I.
Domenden allows that such lapses can only be expected of trailblazing endeavors. "It's the first municipality in the country to pursue the commercial application of the technology. And I think it's just normal for the pioneer to at least experience the best and the worst before they can come up with the most ideal situation."
As it is, "human errors" have attended the proliferation of fish pens and cages. Many operators, says Arlene de la Vega, an aquaculture specialist based in Bolinao, have this notion that doubling the number of stocks means double production and higher profits without regard for the limited carrying capacity of the water.
Milkfish growers, de la Vega observes, also tend to be "price-conscious instead of quality-conscious" in their practice. Feeds commonly used were found to be of inferior quality and contain a high percentage of fines, or poorly processed particles that end up as wasted feeds.
Rey Padilla, a fish cage worker, sadly typifies the lack of training that ought to have gone into such ventures. He seems to think that feeding the fish is a mere matter of common sense. "We just feed them, plain and simple," he says. "With the small ones, you give fry mash, the bigger ones crumble, then starter, up to the grower."
What fish cage workers like Padilla do not know is that feeds that do not get eaten by the milkfish, and the fishes' own waste—fecal material, urine—add to the nutrient load into the water body and only contribute to a condition called eutrophication. A lot of nitrate and phosphate is produced when these materials are broken down.
While these nutrients provide more food for phytoplanktons (microscopic plants in the water) for the consumption of zooplanktons (microorganisms that are in turn eaten by the fish), their proliferation increases the use of dissolved oxygen in the water column. The fish that are enclosed in pens and cages have to contend with a depleting oxygen concentration. At some critical stage, there is simply not enough oxygen for all of the fish and they die. As Jacinto points out, the fish kills that have occurred since February in Pangasinan, were manifestations of systems gone eutrophic.
The other worrisome aspect of eutrophic water conditions is that it could also lead to a bloom of harmful algae. This was the case with this town's February fish kill, which was accompanied by a proliferation of harmful algae.
Identified as Prorocentrum minimum, its occurrence at such a massive scale is unprecedented in the country and, the UPMSI says, is not likely to be the only potentially harmful species now present in Bolinao's coastal waters.
Such a perturbed system may be compared to Manila Bay's, where a new, dominant plankton has multiplied so much as to give its waters a greenish to brownish color. In the past, there used to be only the harmful algal bloom associated with red tide incidents. In the case of Laguna de Bay, the presence of the predominant blue-green algae whose periodic blooms occur between July and September have also been associated with fish kill incidents in the lake.
Examples of the harm too many fish pens and cages bring to its host environment are documented by a recent study conducted by UPMSI and the Marine Environment Resource Foundation (MERF) as part of the resource and social assessment of Lingayen Gulf undertaken by BFAR's Fisheries Resource Management Project (FRMP). The study confirms the worsening water quality conditions in the Lingayen Gulf as a result of increased aquaculture activities in the last six years.
The change in water quality is exemplified by the case of Bolinao where the threefold-increase in fish pen and fish cage structures has resulted in a corresponding increase in nutrient levels of ammonia, which is mostly released from the nitrogen in feeds, as well as those of nitrite, nitrate and phosphate. The high nutrient levels explain the higher phytoplankton and zooplankton biomass especially in enclosed areas as the Caquiputan Channel.
The study also reveals that the recovery rate of the coral reefs in the Lingayen Gulf have been reduced by the presence of algal growth. Coral cover in the Gulf was found to have declined to only 30 percent over two decades, with the majority of live hard coral cover estimates being poor and fair.
Meanwhile, there have been reports of algal bloom and sediment accumulation in Siyt Bay in Negros Oriental where fish cage operations given to bangus culture began in 1997. Water quality tests conducted by the Silliman University Marine Laboratory showed high presence of nitrates and phosphates in Siyt Bay.
The Southeast Asian Fisheries Development Council (SEAFDEC) has also raised concerns over the potential contamination of the water because of aquaculture activities in Northern Iloilo, where fish pen and fish cage operations have also invaded the coastal waters of Tinagong Dagat, known to the locals as Plandico Bay.
"And we have not even factored in the issue of diseases yet," remarks Jacinto. "In areas where you have intensive culture, it is known, I think our experience with the prawn industry bears witness to this. You have in turn the prevalence of diseases, some of which are difficult to naturally counter."
In fact, last November, prawn farms in Tinagong Dagat Bay in Capiz, the country's acknowledged seafood capital, suffered deaths of cultured prawn, shrimp, crab and other crustaceans due to a mysterious disease. A SEAFDEC team that went to check on the situation there traced the prawn kill to chemical causes but could not determine the origins of these.
"But anyway, the primary reason we went actually to Capiz is to undertake field sampling of its estuaries because, of all the provinces in Panay, the situation there points to a runaway development of pens and cages," says Dr. Jurgenne Primavera of the SEAFDEC Aquaculture Department based in Iloilo.
In truth, fish pens now line up both sides of the Panay and Palina Rivers, and worse, serve as extensions of fishponds along the riverbanks long expropriated by private locators. These have displaced the lift nets and other artisanal fishing gears of municipal fishers and blocked their navigational routes.
It may take a massive fish kill to wake the people of these communities to realize what their waters are being subjected to. Lino Fernandez, whose pens suffered from the recent fish kills in Dagupan, for instance grumbles that he is now waiting for a longer period of time to harvest smaller-sized bangus. But he also acknowledges that pen owners like him contributed to the sorry situation.
"That was one of the causes, the rampant setting up of pens, it was just too much, with some even in the middle of the waters," says Fernandez. "That should be regulated so everything will be in order. When areas are regulated, maybe fish kills could be avoided."
Still, there are indications that some communities will not need dead fish as a wake-up call. News reports of what fish pens and cages have wrought here and elsewhere have apparently reached the subsistence fishers of Badian Bay in Cebu, who have expressed fears that the 40 fish cages set up recently in their traditional fishing grounds would only bring similar problems. Fishers of Calatagan in Batangas, where mangroves continue to be cut to give way to renewed interest in fishpond operations, echo their worries.
SEAFDEC's Primavera puts it this way: "Since water is the medium, it is shared whether you are in a pen or in a pond or in a cage, or out in the open waters. It's the same water. It's different with an aquatic medium."