Floating tsunami trash to be a decades-long headache

FRANCE : The tsunami that ravaged northeast Japan in March 2011 created the biggest single dumping of rubbish, sweeping some five million tonnes of shattered buildings, cars, household goods and other rubble into the sea.

About three-and-a-half million tonnes, according to official Japanese estimates, sank immediately, leaving some 1.5 million tonnes of plastic, timber, fishing nets, shipping containers, industrial scrap and innumerable other objects to float deeper into the ocean.

Marine experts poring over the disaster say the floating trash adds significantly to the Pacific's already worrying pollution problem.

For many years, and possibly decades, items will be a hazard for shipping, a risk for sea mammals, turtles and birds, a hitchhiking invitation for invasive species and a poorly understood threat to wildlife through plastic micro-particles. “In a single stroke, the tsunami dumped 3,200 times the amount of rubbish that Japan discharges annually into the Pacific,” said Robin des Bois, a French environmental group that is studying the problem.

“In plastic alone, the volume is the equivalent to several decades of accumulated waste in the Atlantic and Pacific.” Early last year, the first debris started to wash up on shores of Oregon, Washington and southern Alaska and the Canadian province of British Columbia.

They were foam and buoys that have “high windage”, meaning objects that sit proud of the waves and are easily pushed by the wind.

They were followed by other items that sometimes spoke poignantly of the disaster on the other side of the ocean.

They included a Harley-Davidson motorbike in a container, a football with the owner's name on it, a crewless ship and two massive concrete docks on styrofoam floats. The docks came from the fishing port of Misawa in Aomori prefecture, yet washed up in Oregon and Washington eight months apart.

One dock was rinsed down with bleach as a bio-precaution after it was found to be studded with dozens of foreign species of algae and barnacles.

AFP