An enormous amount of debris has been found across a wide swath of waters off western Japan following recent torrential rains that devastated the region with landslides and flooding, land ministry officials said Thursday.

The amount of debris could be the largest on record originating from heavy rains in Japan and is starting to have a negative impact on the fisheries industry.

A total of 5,115 cubic meters of driftwood and marine debris have been retrieved by five regional bureaus of the ministry in the central, western and southwestern Japan from July 8 to Tuesday.

The amount collected so far by the bureaus is four times greater than the average for July over the last three years, according to the Ministry of Land, Infrastructure, Transport and Tourism.

The Chugoku regional bureau covering Hiroshima Prefecture, one of the hardest hit areas by this month's deluge, has already retrieved marine debris of 1,090 cubic meters, or about 70 percent of last year's total amount.

On Wednesday, the bureau recovered debris off the city of Kure, using a sea surface cleaning ship. A container with a capacity of about 8 tons was filled up in about an hour with items including Japanese tatami mats and refrigerators.

"I have no idea how great the overall amount will be," an official of the bureau said.

Some fishermen were unable to operate for a while as the garbage was entangled in fishing nets and they needed to remove driftwood and clean bay areas, according to the Fisheries Agency.

In the city of Kobe, a huge amount of debris was found washed ashore at all seven fishing ports, with an official in the local fishery industry saying that it will "definitely be affected by a fall in catches."

The government still only has a fragmented picture of the full damage as the downpours in early July left more than 200 dead and destroyed tens of thousands of homes, roads and other infrastructure.

Debris that has washed up on shore includes dangerous materials as the flooding also hit gas and chemical factories.

In one case, hundreds of gas cylinders and drums were washed away to the port of Mizushima in Okayama Prefecture. But most of them have been retrieved with the help of the Japan Coast Guard.