A purse seiner is a type of fishing vessel designed to catch fish using a large net called a purse seine. This net is deployed around a school of fish, and its bottom is drawn tight like a purse, trapping the fish inside. Purse seiners are commonly used to catch species such as tuna, sardines, and mackerel. These boats can vary in size, from small vessels to large commercial ships, and are often equipped with advanced technology like sonar to locate fish. Purse seining is an efficient fishing method, but it can also raise concerns about overfishing and bycatch, which refers to the unintended capture of non-target species.