The Yomiuri Shimbun –
TOKYO — The Japanese and U.S. governments are concerned about a large amount of Pacific Ocean debris, set afloat by last year’s tsunami caused by the Great East Japan Earthquake, that is expected to reach the U.S. West Coast starting in autumn.
The trouble stems from the lack of an international agreement on who is responsible for disposing of debris released into the sea. Experts have also said harmful substances mixed with debris will likely damage the marine environment.
According to Japan’s Environment Ministry, the total amount of debris resulting from the March 11, 2011, disaster in the three stricken prefectures of Iwate, Miyagi and Fukushima is estimated at 18.11 million tons. About 4.8 million tons of additional debris is further believed to have been washed out to sea.
About 70 percent of drifting debris consists of such things as cars and cargo containers. Most debris is believed to have sunk off the coast of the Tohoku region. However, the remaining 30 percent, or about 1.54 million tons, became floating debris, including collapsed houses and wood from disaster-prevention forests. These articles have been drifting in the Pacific Ocean since the disaster.
A large amount of debris is expected to wash ashore on the U.S. West Coast in October or later, according to the Environment Ministry’s calculation based on data collected from satellite images and ocean currents.
Drifting debris such as a fishing boat and motorcycle have already landed on the U.S. coast. It became a local news phenomenon when a large floating pier from Aomori Prefecture washed ashore in Oregon.
Members of nongovernmental organizations both in Japan and the United States held a meeting in Oregon early this month and started studying measures to deal with the floating debris.
Azusa Kojima, secretary general of the Japan Environmental Action Network, an environmental nongovernmental organization, said after returning to Japan, “What the U.S. side wanted most was concrete information about the debris — how much and what kind will be washed ashore and which areas or coastlines in Oregon it is projected to land on.”
To deal with drifting debris, an official at the Cabinet Office’s Secretariat of the Headquarters for Ocean Policy said: “No international rules (about drifting debris) exist and it’s become the custom that a country in which debris drifts ashore bears the costs of clearing it. However, it’s difficult to deal with the situation this time as there’s no precedent for such a large amount of drifting objects being washed ashore.”
The Oregon state government paid the demolition cost of the floating pier in Oregon, which was about $84,000.
The headquarters official said, “We can’t let the U.S. side solely dispose of debris, as we received a lot of assistance from them during Operation Tomodachi after the disaster.”
The headquarters is studying what Japan can do to resolve the issue.
Debris washed away by tsunami is believed to have little possibility of radioactive contamination, as most was already far into the ocean by the time of the outbreak of the crisis at the Fukushima No. 1 nuclear power plant occurred.
However, Tokai University Professor Masahisa Kubota, an expert on marine physics, expressed concern, saying, “Plastic rubbish contained in debris will seriously damage the environment.”
According to Kubota, plastic materials made from petroleum are prone to absorbing toxic chemicals in seawater. If birds and fish eat plastic broken into small pieces by waves, they will eventually carry the potentially contaminated substances into the bodies of other creatures throughout the food chain.
“The only way to prevent this is to collect as much debris as possible,” he said.