Channel catfish farmed in the U.S. in ponds is rated green. U.S. catfish farms are usually sited on old agricultural lands in shallow ponds, and they can have beneficial effects by functioning as artificial wetlands. On average, ponds are drained about every 11 years, and there are no cumulative environmental impacts when draining occurs. Chemical use is well-regulated and safe, and the incidence of disease has declined over the last two decades. In addition, no fishmeal and fish oil are used in the feed, which is made primarily from agricultural crop-derived ingredients. The industry is also managed well, and extensive data are available.