"Their feed is not natural — in the wild, tilapia would eat algae and lake plants, but the farms fatten up the fish on GMO corn and soy pellets. The amount of healthful fish oils in these creatures is almost non-existent, negating the main reason why fish is so good for us.
Why Farm-Raised Tilapia is So Bad for You
2. Cancer Causing Pollutants
3. Pesticides and Antibiotics
4. Poor Omega-3 to Omega-6 Ratios
5. High Dioxin Levels
See explanations @ Eat Local Grown