I work in one of these hippie health food stores stocking the freezer and I have to answer a lot of unbelievable questions. I could almost imagine customers being concerned about some kind of GMO fish pellet or lousy water in fish farms. ALMOST. But it turns out this is true.
But, you have to have the right kind of fish genetics to get then to finish on pond weeds...... http://m.huffpost.com/us/entry/827801
I recently had someone tell me they only bought "grass fed" turkey meat! I've worked with the turkey industry for 30 years and I didn't know there was such a thing!!