For the Ukai tradition, that has been practiced for many years, trained fisherman use cormorant birds to catch fresh ayu(or sweetfish). The fishers put a ring around the neck of the birds. These rings allow small fish to pass through so that the birds get to eat and are motivated to fish, but the big fish cannot pass through. They catch around four or five and then the fisherman pushes them out of their neck. This fishing practice is passed down on through families in Gifu, which means that the fishermen who perform this tradition in Gifu have a long family history based in this tradition. The master fisherman take care of the cormorant birds all-year round, even though Ukai is only carried out in the summer.
During this tradition, many people watch the fisherman from boats on the river. While watching, most people enjoy a bento box that has cooked ayu, which is a type of fish that you can't miss out on. The two most popular ways to eat the ayu is to either salt and grill it, or sweetened and boiled. (You can find restaurants that serve ayu in Gifu, even when it is not ukai season.) Many people enjoy the view of Gifu castle on the mountain top from the boats. The festival takes place in the evening so the fishermen use a fire at the front of their boats, which makes for a very beautiful sight with a relaxing atmosphere.
Gifu is very proud of this tradition, and it is the biggest event that they hold. Many of the souvenirs from Gifu are themed around the local, fresh caught ayu. In the markets, the ayu with a mark from the birds beak, which shows it was caught in this traditional way, fetch a high price. Gifu also has a museum dedicated to this tradition, and it is well worth the visit.