In response to the large amount of pumice stones washed ashore along the coasts of Okinawa and Kagoshima prefectures, the Ministry of Land, Infrastructure, Transport and Tourism held a meeting with experts in marine civil engineering work to discuss effective recovery techniques.

The results of the study will be compiled during November, and a large amount of pumice stones shared with the coastal municipalities will be washed ashore.

In Okinawa and Kagoshima prefectures, a large amount of pumice stones have been washed ashore on the coast and harbor since mid-October, which has affected the fishing industry and the lives of residents, such as the inability of ships to navigate. Is going through trial and error.

On the 5th, the Ministry of Land, Infrastructure, Transport and Tourism, which has jurisdiction over the ports where cargo ships berth, except for fishing ports, held a meeting to examine techniques for collecting plight stones, and was in charge of associations and national research institutes made by marine civil engineering construction companies. Etc. attended.

At the beginning, Mr. Takamitsu Asawa, Director of the Port Bureau of the Ministry of Land, Infrastructure, Transport and Tourism, said, "There is a risk that pumice stones will be washed ashore in Honshu in the future, so it is necessary to prepare for a wide area response."

The meeting was held privately after this, and as an example of on-site work, with a pump that sucks suspended matter together with water, the amount of pumice contained in the collected water is only about 2% of the total, and the backhoe It was shown that using a net can collect a large amount in the same amount of time.

Participants commented that the more appropriate collection method may differ depending on where they are collected, such as from the quay or from the ship, and the process of trial and error in the field will be helpful, so please collect detailed examples. It means that the opinion came out.

The Ministry of Land, Infrastructure, Transport and Tourism will compile the results of the study later this month and share it with Okinawa and Kagoshima prefectures as well as coastal municipalities that may be washed ashore in the future.

Japan Coast Guard Confirmed drifting and drifting in 6 areas

The Japan Coast Guard confirms the condition of pumice stones during patrols by aircraft.

By the 5th, it can be roughly divided into

▽ offshore of Okinawa main island, ▽ around Okinawa main island, ▽ around



Kagoshima prefecture, ▽ around Amami Oshima,

▽ offshore in south of Kochi prefecture,

▽ erupted Fukutoku Okanoba It

means that drifting and drifting were confirmed in the


6 areas.

In addition, the extremely strong ocean current called "Kuroshio" that flows from west to east in the Pacific Ocean off the coast of Japan has a straight-ahead type that goes straight along the coast and a meandering type that makes a big turn, and according to the Japan Coast Guard, it has recently meandered. It is flowing in a mold, and it is expected that the same flow will continue in the future.

At high speeds, the flow is over 2 meters per second, and pumice stones may ride on the Kuroshio Current and drift off the coast of the Kanto region in the future. We are calling for confirmation and regular confirmation of the "seawater strainer" that removes impurities from the seawater pumped up to cool the engine.

Damage situation in each area

The damage caused by pumice stones up to the 4th, compiled by the Cabinet Secretariat based on information from each ministry and agency.

Confirmed drifting at 46 fishing ports

As for fishing ports, pumice stones have been washed ashore at 34 locations in Okinawa Prefecture and 12 locations in Kagoshima Prefecture, for a total of 46 locations.

Of these, 39 fishing ports have had a minor impact or have been washed ashore, but there are 7 locations in total, 6 in Okinawa Prefecture and 1 in Kagoshima Prefecture, which hinder the entry and exit of fishing boats, and pumice stone recovery work. Is underway.

42 fishing boats have engine trouble

As for fishing boats, a total of 42 boats have been damaged by pumice stones causing engine trouble, and 6 of them have become inoperable.

Confirmed drifting at 35 ports

At ports where cargo ships berth, excluding fishing ports, pumice stones have been washed ashore at 21 locations in Kagoshima Prefecture and 14 locations in Okinawa Prefecture, for a total of 35 locations.

Although the impact on the 12 ports is minor or the drifting has been resolved, pumice collection work is underway at 23 locations in total, including 12 in Okinawa Prefecture and 11 in Kagoshima Prefecture.

Of these, at Yoron Port on Yoron Island in Kagoshima Prefecture, a tanker carrying oil to the island tried to enter on October 25, but pumice stones were drifting on the quay, so the port was abandoned.

Since the island has oil reserves until early December, the Ministry of Land, Infrastructure, Transport and Tourism is urgently responding by sending a ship to clean the sea surface to the site.

Confirmed drifting at 173 locations on the coast

As for the coast, pumice stones have been washed ashore at 83 locations in 17 municipalities in Okinawa Prefecture and 90 locations in 12 municipalities in Kagoshima Prefecture, for a total of 173 locations.

According to estimates reported by each prefecture, the amount of drifting in Okinawa prefecture is about 150,000 cubic meters, and the amount of drifting in Kagoshima prefecture is about 5,000 tons. We have decided to apply the subsidy system to the collection of pumice stones.