Optimal Focus says it contains fish and shellfish, yet is suitable for vegetarians and vegans. How is that possible?

Optimal Focus does not contain any products derived from fish or shellfish. However, it does contain algae. Since this algae could have potentially come in contact with fish or shellfish, we cannot guarantee it is free of fish or shellfish allergens. We have labeled the product as containing fish and shellfish to play it safe for those with allergies to these foods. 

†These statements have not been evaluated by the Food and Drug Administration (FDA). This product is not intended to diagnose, treat, cure, or prevent any disease.