Fish do not actually produce omega 3. They feed on algae, which are the primary source of this nutrient in the oceans. Fish oil extraction has a major environmental impact, which leads to imbalances in the marine ecosystem. On the other hand, algae can easily be grown and produced as a concentrated oil in DHA (a type of omega 3), which in contrast to fish oil is much more sustainable alternative. In addition, because of the production in a controlled environment, seaweed oil is naturally free of toxic unlike contaminants found in fish such as heavy metals, PCBs and dioxins.