Aquaculture is the production of aquatic animals and plants under controlled conditions. Over the past two decades, the structure of the U.S. aquaculture industry has changed considerably, while U.S. demand for seafood has expanded. From 1998 to 2005, the number of U.S. aquaculture farms grew from 4,028 to 4,309, but sales of products from those farms, adjusted for inflation, decreased by 6.8 percent. From 2005 to 2013, the number of aquaculture farms fell to 3,096, but inflation-adjusted sales grew by 5 percent. The number of farms continued to decline, reaching 2,932 in 2018. However, sales by aquaculture farms from 2013 to 2018 grew almost 3 percent, reaching about $1.5 billion or about $1.8 billion in 2023 dollars.