Videos of dead fish

Dear Editor,

Some videos recently shown on social media have shown a lot of fish – particularly tilapia – floating in our canals around the city. One particular video showed what looked like hundreds of fishes floating at the mouth of a koker. Fishing in these canals is a favourite pastime of many citizens both young and old. My children actively participate in such activities on some weekends. The videos being circulated have obviously raised concern as to what is causing this mass death among the fishes? Is it something that the public should be warned about? After all, most of the fishes caught invariably end up as food. 

Could someone in authority please shed some light on this situation?

Yours faithfully,

M. Abraham