Found this:
Poisoned Waters
Do we know this is happening? Do we choose to ignore it? At one time, about 10 years ago, it is believed that because of public outcry, the harvesting of ornamental fish with cyanide pretty much stopped, but today it is widespread once again. Fisherman need to feed their families and collecting fish for food is made easier with poison, which unfortunately, is so readily available that in some locales it's often used for collecting ornamentals as well.

Aloha,
Mark