Why are you afraid of genetically modified foods? What specific harm are you worried about?
Wild salmon is not healthier than farm raised salmon either. They have the same ratios of pollutants (some farmed salmon actually have a lower ratio). The fact that farmed salmon have a higher fat content and thus a higher total content of pollutants made the news several years ago. It alarmed a lot of the people. But that's why we eat salmon, for the fat (Omega 3 fatty acids).