DAVAO RIVER FISHKILL CAUSED BY POISONS

Davao City, May 10, 2003 -- Scientists call it "the 15-minute killer," 
suffocating its victims by choking the flow of blood to the heart  just 
like what probably happened to the fishes at the Davao River. Laboratory 
results sent to Manila to determine the cause of what could have been 
Davao's worst river fishkill last month has yielded a high presence of 
cyanide, perhaps more than 700 times higher than the safety level.

But government agencies supposedly mandated to guard against these 
situations are still in a quandary as to what really caused the fishkill.

Ilominda Salting, regional director of the Fertilizer and Pesticides 
Authority, offered a number of possibilities, all of them ruling out the 
number of banana plantations operating near the area, most notably the one 
owned by the family of Agriculture Secretary Luis Lorenzo.

"We are not sure what killed the fishes," Salting said.

The results of laboratory tests conducted by the Pesticide Analytical 
Laboratory here in Davao City found no traces of Isazofos, the active 
ingredient for the pesticide Miral (already banned in the market), and 
Terbufos, the active ingredient for the fungicide Counter, she said.

The FPA had also requested for a multi-pesticide residue analysis for 
Terbufos, Deltamethrin, and chlorothalonil from JEFCOR laboratories in 
Manila, and the results were negative.

Deltamethrin and chlorothalonil are active ingredients of the fungicide 
Daconyl used by the nearby banana plantations. "Based on analysis, the 
presence of Terbufos, Deltamethrin, and chlorothalonil are not detected," 
Salting said.

Instead, the Manila firm has found a more lethal substance at dangerously 
high levels. "There is cyanide at 3.7 milligrams per kilogram of fish 
sample," Salting disclosed.

Ma. Loida Avorque, a chemist from the Bureau of Fisheries and Aquatic 
Resources in Southern Mindanao, said cyanide is a highly volatile 
substance, which means that "it may or may not" have killed the fishes.

Yet she also said banana plantations could not have used the dangerous 
substance for their crops.

"I've worked in banana plantations before but they are not using this 
chemical," Avorque said. "Unscrupulous people may have used this to catch 
fish."

Avorque said 3.7 mg/kg, which is also equal to 3.7 parts per million (ppm), 
would be enough to kill small fishes smaller than one kilogram. But she 
said the BFAR could not yet determine if it was enough to have killed big 
eels because of the volatile characteristic of the substance.

"Some will die while some don't," Avorque said.

She said "unscrupulous fishers" use cyanide because it doesn't kill large 
fishes outright at small doses but will only make them immobile and 
therefore easier to catch.

As far as she knows, Avorque claimed, cyanide is only used in industrial 
mining and in catching ornamental fishes.

Toxic

However, the strict enforcement of R.A. 6969 or the Act to Control Toxic 
Substances and Hazardous and Nuclear Wastes would make it hard for an 
ordinary fisher to get hold of cyanide.

Gregorio Estrada, regional director of the Environmental Management Bureau 
in Southern Mindanao, said enactment of the law and the drafting of the 
implementing rules and regulations have resulted to the strict monitoring 
of most dangerous and banned substances nationwide, including cyanide.

"Prior to the enactment of the law, cyanide can be bought over the 
counter," Estrada said, adding that the EMB only gave permits to four 
industries in the region, three in Tagum City and one in Compostela Valley.

With the new development, the EMB will conduct spot checking in nearby 
companies to ensure that nothing is lost in their inventory, Estrada said.

Elements of the Criminal Investigation and Detection Group were able to 
apprehend last February shipments of cyanide with 10 drums per shipment. 
They are now stocked at the EMB office.

Estrada however said the ENB is still not discounting the possibility of 
employees by mining industries stealing small volumes of cyanide and 
selling it on the black market.

Based on the EMB survey, there are at least three industries operating near 
the banks of the Davao River, and one already shut down a decade ago.

Superstar in Maa produces desiccated coconut while Premium AC along 
MacArthur Highway in Matina produces active carbons. The third one is MA 
Foundry.

Crown Factory already closed down 10 years ago.

What happened?

So what really caused the fishkill? Both the FPA and the EMB offer several 
theories. Estrada said low depletion of oxygen may have caused the 
fishkill, although cyanide could be a major culprit.

According to the Department of Environment and Natural Resources' standards 
of classification of surface waters, the Davao River has been categorized 
as Class B or suitable not only for fishing but also for the designated 
uses of drinking water supply after treatment, recreation both in and above 
the water, industrial processing and cooling of water supply, and even 
hydroelectric power generation.

"The allowable level of cyanide in DENR standards of Class B waters is .05 
mg. per liter," Estrada said, adding that the level at the Davao River last 
month was at around 740 times higher than the standard.

Another possible cause, Estrada said, would be the change in the 
temperature, Estrada said. Long droughts would result to "quite high" 
temperatures in the surface and bottom waters.

"A 3 oC rise in temperature will already affect the oxygen balance in the 
water," Estrada said.

For her part, Salting said the FPA asked barangay officials on the behavior 
of fishes immediately that day. "They described the fishes as gasping for 
breath and all were swimming at the surface," Salting said, adding that 
this could indicate oxygen depletion in the bottom of the water.

The manner in which the fishes died would also discount pesticide poisoning 
because their pectoral fins would have been rigid, contrary to the fish 
samples they got with fins hanging limp, Salting said.

Oxygen depletion almost always occur at night or the wee hours of the 
morning while "fish toxicity can occur day and night," Salting claimed.

"They told us that the lower portion of the river is really hot," Salting 
said, adding that the phenomenon is not really that rare considering that 
many rivers can become anoxic (depleted with oxygen in deeper areas), 
attributed to long dry spells in the weather conditions.

Citing another fishkill in 1997, Salting said laboratory findings also 
found high traces of cyanide in the fish samples. The culprits in that 
fishkill were never identified.

What now?

After the recent fishkill, the different agencies agreed to create a task 
force composed of the EMB, the FPA, the BFAR, and other government-line 
agencies for a massive information and education campaign for the people 
residing in the riverbanks to know the dangers of using banned chemical 
substances.

The task force, Estrada said, will also monitor industries operating along 
the river to ensure that they are not violating any environmental law.

Assistant BFAR regional director Fatma Chaneco said the City Fisheries and 
Aquatic Resources and Management Council should also be included in the 
task force because it is the proper body to keep illegal fishing activities 
in check.

Already, the EMB and the FPA are tasked to monitor those establishments and 
industries using pesticides and chemicals.

In fact, the EMB is conducting random spot checks, as some riverside firms 
are required to submit a report every three months about their operations. 
(By Joel B. Escovilla, Mindanao Times)

Reported by: Sol Jose Vanzi

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