There was a huge fishkill in Taal Lake in Batangas Province, Philippines last January 22, 2014. It came out in the newspaper that there was about 120 metric tons of dead fish found in the fishcages in that lake. The fish species is bangus or milkfish, which is one of the favorite food of Filipinos.
Usually a fishkill happens when there is a low level of dissolved oxygen in the lake water. This has happened several times in our seven crater lakes in San Pablo City where I live. Other possible reasons for a fishkill are algal bloom, too much fish in the fishcages, sudden change in temperatures and sometimes fish disease. In the case of the Taal Lake fishkill last week, the government said it is possibly due to high levels of sulfur in the water from the active lake.
About a week ago, we had lots of huge fishes that turned up close to the shoreline of Sampaloc Lake just outside our home. The fisherfolk said that it was because the temperatures were so low that there was a turnover or inversion of the water and the fishes got confused. They swam upwards where it ended up that the dissolved oxygen level was much lower than they needed. That's the picture of the fishes below.
Right now we are experiencing unusually cold weather. The past few nights we had 16 ? which is much lower than the usual temperature we have. So I will not be surprised if we have a fishkill too one of these days in our crater lakes.
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