Fishkills are here again, this time in Taal Lake. The TV stations on May 30 showed several thousands of dead fish, mostly the milkfish or bangus, floating on the water in fish pens.
The announcements said the fish died due to lack of oxygen resulting from the crowded conditions in fish pens. Some TV commentators attributed the cause of death to chemicals in the water presumably produced by volcanic processes. Whatever the cause, it was clear that the fishery loss could run into several millions of pesos.
Concerns about what to do with the dead fish were heard. There were fears that the dead fish will be sold in markets for human consumption.
Definitely, the floating fish are not fit for human consumption. The reason why they floated is because of the accumulation of gases in their body cavities produced by bacterial action. Dead fish are, therefore, unfit for human consumption and are only fit for conversion into organic fertilizer. In fact, the TV showed that some fish were being buried.
Taal Lake should not only be used for aquaculture but should also be conserved for its biodiversity and historical values, being the only freshwater lake formed after its continuity with the sea was cut off. As a result, there are unique aquatic fish and reptile species found on in this lake.
In the Philippines, practically all inland lakes are utilized for fish culture. More often than not, these lakes are overused as aquaculture sites. They are stocked with many more fish individuals than can be supported by the lake environment.
In other words, the number and biomass of fish being cultured exceed the normal carrying capacity of lakes. There is no effective control being exercised by the Bureau of Fisheries & Aquatic Resources or the Department of Environment & Natural Resources.
I understand there are enough guidelines but they are not implemented. I talked to an official of DENR, and he told me that the guidelines are difficult to implement because many of the owners of fish pens are the rich and the influential, including retired government officials. There is practically little management effort of our freshwater habitats and biodiversity.
So no one should be surprised why fishkills occur in our freshwater lakes. Many people would like to coax the environment to produce more and more fish without realizing that times will come when the abused environment will take its revenge.
Greed was the cause for the collapse of prawn culture in the country. Those who were making so much money wanted to earn more, so they overstocked their ponds and used chemicals to produce more prawns. What ended the chain was the rise of bacterial populations that negatively affected the quality of the prawns produced, resulting in the rejection by the world market of prawns.
As several fishkills have been reported in lakes in the past, it is obvious that aquaculturists have not learned lessons from these events.
As long as they continue to ignore the lessons of the past, and as long as government fails to regulate aquaculture activities, there will always be fishkills.