The government has intensified surveillance in the Izu and Ogasawara islands after more than 200 vessels believed to be Chinese boats were observed in areas around the islands. They are believed to have been poaching coral to make jewelry.
On Thursday afternoon, a Japan Coast Guard plane observed 48 boats around the Ogasawara Islands and 164 boats in the vicinity of the Izu Islands.
On Friday, a Yomiuri Shimbun plane spotted a group of vessels near the Izu Islands.
The Izu Islands are closer to Honshu than the Ogasawara Islands, and experts say the vessels seen there are seeking to strike it rich in an area where coral has never been harvested.
Boats were observed in two areas around the Izu Islands - Torishima island, about 400 kilometers north of the Ogasawara Islands, and Sumisujima island, about 500 kilometers north of the Ogasawara Islands.
The 3rd Regional Coast Guard Headquarters deployed more patrol boats to crack down on illegal harvesting of coral to prevent the practice from spreading, according to the headquarters.
Crew members in the boats observed by the Yomiuri Shimbun plane were seen in work gloves, busy handling nets.
Although many of the boats appeared old, with some covered with rust, their crews seemed to gathering coral on a large scale with large devices that seemed to be radars and wire containers on the decks of their boats.
The price of coral that can be used for jewelry has jumped more than 100 times compared to that of about 40 years ago.
"We have expressed our dissatisfication about this behaviour to the Chinese government and requested that it not be allowed to happen again," Chief Cabinet Secretary Yoshihide Suga said at a press conference Friday.
'Chinese poachers' seen near Izu Islands
About 80 suspicious fishing boats have been spotted in waters around Torishima island, one of the Izu Islands, as witnessed from a Yomiuri Shimbun airplane on Friday. These vessels are believed to be Chinese boats poaching valuable "jewelry coral."
A Chinese national flag was visible among the small boats.
Coral poaching by Chinese fishing boats has been rapidly increasing around the Ogasawara Islands, which are about 500 kilometers south of the Izu Islands.
On Thursday, the regional Japan Coast Guard headquarters confirmed about 160 vessels spotted in waters around the Izu Islands.