Cormorant fishing is a traditional fishing technique in which fishermen use trained cormorants to catch fish in rivers. Historically, cormorant fishing has taken place in China and Japan, as well as Greece, North Macedonia, and briefly, England and France. Sometimes known simply as "Duck Fishing," it was attested as a method used by the ancient Japanese in the Book of Sui, the official history of the Sui Dynasty of China, completed in 636 CE. Though cormorant fishing once was a successful enterprise, its primary use today is to serve the tourism industry. This artisan fishing method is no longer used anywhere except southwestern China, where it is also under threat from competition from more modern methods.

The ayu sweetfish, ayu or sweetfish, is a species of fish. It is the only species in the genus Plecoglossus and family Plecoglossidae. It is a relative of the smelts and other fish in the order Osmeriformes.