Around half of the fish that the world eats for dinner comes from fish farms. Aquaculture is promoted as a sustainable way to meet rising consumer demand for seafood. But fish farming relies on small, wild fish to feed farmed fish, pollutes the waters around it with wastes and chemicals and threatens wild fish biodiversity through escapes and disease transmission.
The magnitude of these effects is poorly understood. The aquaculture industry has expanded rapidly in the last several decades, producing 59.9 million metric tons of fish in 2010. But few countries require mandatory reporting and public release of aquaculture statistics. For example, China was responsible for 61.4 percent of world aquaculture in 2010, and Asia as a whole produced 89 percent, but aside from production totals, very little information is available about the fish farming industry in these countries.
In this issue brief, we analyze available data on fish farm escapes and disease outbreaks to build a picture of the costs of aquaculture.