Aquaculture, wild fisheries, and consumption of omega-3 fatty acids

Aquaculture (fish farming) -- now the source of nearly half of the world's edible fish -- can help narrow the gap between declining global fisheries and increasing consumer demand for seafood. Nevertheless, some types of aquaculture production actually increase demand for wild fish, rather than reduce it. Feed for carnivorous fish—those farmed fish highest in omega-3s—contains large quantities of fishmeal and fish oil. Salmon farming, for example, requires approximately three pounds of wild-caught fish to produce a single pound of salmon. Without new types of feed ingredients, fish farmers' demand for wild fish will grow if aquaculture production continues it's current rapid growth. Farming largely vegetarian fish such as tilapia, catfish, and carp uses little fish in feeds, but these fish also have low levels of the most heart-healthy omega-3s (DHA/EPA). Similarly, heavy substitution of plant-based proteins and oils for fishmeal and fish oil can result in fish with lower levels of DHA/EPA. Alternative algal and other microbial sources of DHA/EPA appropriate for incorporation into fish feed are in development, but not yet available commercially. As a result, conservation of wild fisheries remains essential to future seafood supplies, both from wild fisheries and aquaculture.