FISH KILL
Fish kill is not isolated in the Philippines only. It happens in other countries as well. In my research, I learned that fish kill is commonly caused by lack of oxygen in the water brought about by rapid blooming of algae, drought, water temperature increase, and too much fish population in a contained area. Parasites and diseases are also causes of fish kill. Poisonous substance may also cause fish kill but it is rare.
In the Philippines, last month’s reported fish kill in Batangas, Taal, and Pangasinan were said to be caused by oxygen deprivation in fish farms or pens. Overpopulation is one of the factors involved in the oxygen deprivation of fishes.
Imagine continuously breeding hundreds of fishes in a contained and limited space Time will come when they can no longer move sufficiently as they are packed tightly. They bump and rub against one another, they might even accidentally rub their bodies at the edges or boundaries of their cages which can injure and harm their bodies. This makes them susceptible to infections and diseases, even communicable diseases.
According to one news agency, fish kill was caused by rising water temperature due to a restive Taal volcano. Their source was the Bureau of Fisheries and Aquatic Resources.
Personally, I think that yes, rising water temperature due to Taal volcano’s eruptive stage might be the culprit but in my lifetime alone, how many times has Taal erupted already? How many volcanoes are near bodies of water? If this is the case, then it follows that everytime Taal will erupt or will show signs of eruption, fish kills will be imminent. But what about Pangasinan? Pangasinan is on the other side of the compass point from Taal volcano. Surely fish kills in Pangasinan have no connection to the condition of Taal Volcano.
Another news agency quoted the Department of Environment and Natural Resources’ notation that an “abrupt drop in temperature caused lack of oxygen”.
What I cannot comprehend is the announcement made by an authority figure of Talisay that fishes in Taal Lake are still safe to eat because whatever killed the fishes are not due to poison. How did one know that it is not due to poison? Up till now, the real cause of the fish kill that occurred last month is still unknown. Yes, it might be due to lack of oxygen but what caused oxygen deprivation? As of this time, DENR is still doing an investigation on whether Taal Lake is safe and non-toxic.
I just wish that those who are in authority should look at and study the facts first before issuing a statement, especially a statement that might affect the life of innocent citizens.
The Department of Agriculture – Bureau of Fish and Aquatic Resources should regularly conduct checking and site inspection to all fish farms similar to the way an electrical engineer is commissioned by the city hall to conduct onsite checking on every building in its jurisdiction. They should give training or seminars to fish cage owners before issuing a license or a permit which can be revoked if, upon inspection, the fish farm is found not to be in accordance with the regulations of the DA-BFAR. They must also circulate advisories.
On the other side, fish farm owners should maintain the right volume of fish population based on the size of their cages or pens. If they see that there is already the danger of overpopulation, then they should harvest their fishes as soon as possible. They must also know how to properly feed and what to feed the fishes. Water quality must be checked regularly to see if pollution has set in. Pollution also causes depletion of oxygen.
Furthermore, owners must bear in mind that overpopulation will not give them additional profit. Rather, it will give them trouble and might even deplete their resources. It might even cause health deterioration if not checked early. Professional and humane treatments are called for here.
I believe fishes can also feel and I think it is so hard to die of asphyxiation.
