August 8, 2011
A fish (kill) tale
An eFeedLink Exclusive

In the Philippines, fish kills are not a rare phenomenon; though devastating, their occurrence happens sporadically and does not necessarily come as a surprise to Filipinos.

However, late May's fish die-offs roused the attention of not only the fishing industry but of the whole country, as they simultaneously occurred in two major aquaculture producing provinces: Batangas and Pangasinan. Aside from hitting the two biggest producing areas at the same time, this die off is the worst in ten years as more than 100,000 tonnes of fish were killed, with losses reaching reach PHP200 million (US$4.64 million).

Authorities say the numbers may still climb as fish fatalities from some towns are yet to be reported. Observers say the disaster was a lethal combination of climate change and arrant neglectful practices on the part of fish farms. Whichever way, experts conclude that the industry is about to face its toughest challenge yet.

Man-made or natural?

According to the Philippine Bureau of Fisheries and Aquatic Resources (BFAR), fish kill results from natural or man-made causes. Factors leading to fish kills include reduced oxygen in the water which may be due to conditions such as drought, algal blooms (caused by phosphate), overpopulation or a sustained increase in water temperature or pollution caused by man. In lakes, a natural phenomenon known as water overturn or upwelling occurs as a result of changes in weather or climate changes-from long dry spells to sudden strong rains, among others.

The country has had a string of notable fish kills over the years. In 2002, fish kill hit Bolinao in province of Pangasinan, destroying about PHP400 million (US$9.35 million) worth of milkfish cultured in fish cages. In 2007, another fish kill hit the Kakiputan Channel between Bolinao and Anda also in Pangasinan, killing at least PHP100 million (US$2.33 million) worth of milkfish. In 2009, a series of fish kills occurred in 1,528 hectares of fishponds in Pampanga, Bulacan and Bataan provinces. Last year, severe water pollution caused massive fish deaths in Lake Buhi in the province of Camarines Sur.

The towns of Anda and Bolinao were again the victims of fish kill and along with them, the towns near the Taal Lake in Batangas, namely Talisay, Laurel, Agoncillo, San Nicolas, Alitagtag, Cuenca and Santa Teresita. According to fish operators, they were surprised to see fishes floating one morning with nary a hint a day before that a fish kill would occur. "It was just an ordinary day. Our fishes were all moving; the waters were calm. We were just shocked to see them dead the following day," recounts one fisherman.

The brunt of the fish kill was so severe that fishermen have to sell their fish for as low as PHP2/kg (US$0.05/kg) from the usual PHP60/kg (US$1.39/kg) to PHP90/kg (US$2.09/kg), as people were afraid to buy fish for fear of contamination. Some fish operators were grieving at the huge financial loss, mulling whether they would be able to live another day. "I don't know where I will get our next meal or our allowance for the next day because nobody buys our fishes anymore," said one fish operator. "Much as I want to feed them with our own fish since I don't have enough money to buy other food, I'm afraid that it's not safe and it might do more harm to my family than good."

Dubbed as the worst fish kill in recent years, aquaculturists say the disaster was a combination of environmental factors and manmade miscalculation. Fish-pen overcrowding, an overcrowding-linked sudden drop in water oxygen levels and pollution have all contributed to the fish kill amid warnings from scientists in recent years of possible destruction of our marine ecosystem due to erroneous fish farming structures.

According to BFAR, the fish kill in Taal Lake was due to lack of dissolved oxygen (DO) caused by the natural upwelling of lakes. Fish are unable to breathe under a low DO. But what really caused the fish kill according to BFAR is the violation of the agency's prescribed Code of Practice for Aquaculture and local government ordinances on proper fish cage management. During its investigations, BFAR discovered that some fish cages had been overstocked and the depths of fish cages were increased from the prescribed five metres to 15 metres.

On the other hand, the fish deaths in the coastal waters of Bolinao and Anda were due to improper fish cage management and overcrowding of fish in the cages. For closed water systems such as lakes, BFAR's prescribed stocking density is 20 fish/cubic metre. For open waters, stocking density could go up to 30 fish /cubic metre or more, depending on water circulation efficiency.

However, fish pens were discovered to contain 30 to 50 fishes per cubic metre, making them more vulnerable to weather changes.  It is like putting 20 gold fish in a foot-high box with daily feedings but without changing its water, its aerator turned off and the box filled with cold water (the cold water coming from seasonal heavy rains), explains Dr Westly Rosario, chief of the National Integrated Fisheries Technology Development.

Rosario said fish cages in the Kakiputan Channel were stocked beyond the carrying capacity of the water as a square metre of fish cage there contained 50 pieces of milkfish, exceeding the recommended stocking capacity of 25 pieces. The overfeeding thus required to maintain such a high fish density then created thick residues of wastes that severely polluted the water with ammonia and oxygen-destroying compounds. This resulted in "choking" the fish, said Dr Edgardo Gomez, professor emeritus from the University of the Philippines Marine Science Institute.

Rosario expressed concern that the situation may worsen due to rains wherein a 10-inch to a metre-deep sludge within the Kakiputan Channel has been found. He said that a sudden downpour would disturb the muck and bring the polluted water to the surface, which would again reduce the DO and may jeopardize the province's marine life.

The disposal of rotting milkfish has also been difficult as the Bolinao sanitary landfill is not enough to accept such a huge volume of dead fish. The stench from the lakes has also been very discomforting to residents as some dead fish were yet to be cleaned from the lake.

Of late, Taal Lake's dissolved oxygen level was still 3.71 ppm, far below from the acceptable minimum of 6 ppm. Experts say that this was due to "overturn" or the combination of cold and hot waters in the lake, causing sediments at the bottom to rise. Accumulated wastes from years of bad practices came up with the disturbed sediments and absorbed dissolved oxygen, causing the fish to asphyxiate. The Department of Agriculture is using 50 pumps to aerate the lake and raise oxygen levels to the point where fish can breathe in it again. However, it will take one or two months for the lake's water oxygen levels to rise and stabilise.

Although Batangas officials deny that there was overcrowding in Taal Lake, reports show that fish pens are beyond capacity to sustain their host fish. This was proven by the recent dismantling of about 1,300 illegal fishpens by the Department of Environment and Natural Resources.

In a report by the Philippine Daily Inquirer, the Taal Lake's protected area management board recommended that its 14,000 fish cages be reduced to 6,000. Unfortunately, numerous fishpens and cages were still being constructed. That is because local authorities are unmindful of its devastating effects to the lake and fish because of sheer greed and politics.

In fact, a disturbing report surfaced recently that thousands of illegitimate fishpens were owned by retired generals and politicians who are the biggest operators of giant fishpens at the Laguna de Bay. Moreover, an elite group of fish farm operators, mostly composed of rich business scions, are said to own 10 of the largest fishpens that add up to 4,000 hectares (the law says that no person or corporation can own more than 50 hectares of fish pen franchises) of the lake area. Their political weight may explain why the Laguna Lake Development Authority (LLDA) was unable to dismantle large fishpens which were said to be the root of a big fecal waste sludge deposit on the lake bottom which was caused by overstocking, overfeeding and failure to properly clean out waste. For fear of retribution from these "powerful" people, LLDA and other related agencies would just readily approve fish pens/cages, with or without bribery, even if it meant environmental destruction and eventually, economic ruin.

A slow recovery

The Philippine Star reported that the waters in Taal Lake and in two towns of Pangasinan hit by fish kill may need at least two years to recover. Citing the study of Rudy Castro Flores, director of the Bataan Peninsula State University-Orani Campus, the decomposition of excess fish feeds in the fish kill areas has only just started and needs years to complete its decomposition process.

Flores said excess feeds triggered algal blooms and development of other organisms which use up dissolved oxygen and caused a very thick build-up of fecal-waste-based pollution, which will not be easy to remove. Should the unregulated practice continue, the recovery may take longer, he said.

A militant fisheries group has urged the immediate release of PHP90 million (US$2.08 million) calamity fund for immediate economic relief for small-scale fish farmers affected by the fish kill. As they will be unable to make a living off fish farming for several years, the groups also demanded an alternative livelihood, cash assistance and a sack of rice to every family while still recovering from the tragedy.

While still scouring for solutions, the fish kill is indeed a powerful reminder that people should not abuse nature or nature would strike back.  A strong political will may very well be the very first stage to preserving our aquatic environment and protecting millions of fish farmers who depend on aquaculture for their livelihood.

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