The Japan coast guard identified the trawler and its owner after Canadian officials provided the identification number on the hull of the ship.

CNN: U.S. Coast Guard sinks Japanese boat washed away by tsunami

The Japan Coast Guard identified the owner of the vessel after being contacted by Canadian officials, who were provided the identification number on the hull.

CNN: U.S Coast Guard sinks Japanese fishing trawler near Alaska

While the Japan Coast Guard is responsible for protecting Japan's coastlines, the defense minister can order the Self Defense Forces to be deployed for maritime security operations if the situation is considered beyond the coast guard's capabilities.

WSJ: Japan on Alert Over Submarines Near Its Territorial Waters

Ironically, the accident happened only one day before a ship carrying nuclear fuel made up of mixed uranium and plutonium docked in Japan, surrounded by coast guard vessels and greeted by demonstrators.

CNN: 'We're Scared for Our Baby'

Coast Guard official Yasuhiko Oku said the captain had admitted being inside Japan's exclusive economic zone when he was stopped on Saturday, the Associated Press reports.

BBC: Japan frees crew of 'illegal' Chinese fishing boat