The International Pacific Research Centre at the University of Hawaii estimates up to 20 million tonnes of debris was washed away in the tsunami that followed Japan's 9.0 magnitude earthquake last March.
Seven months later, a TV set, a fridge, and buoys from fishing nets have been found floating in the Pacific more than 3,000km from the disaster zone.
A scientific programmer at the research centre, Jan Hafner, says the biggest find was a six-metre long fishing boat which was hoisted onboard a Russian training ship this week.
"We know that it is from Fukushima because of the markings on the boat. There is a registration number and the number says it is registered in Fukushima prefecture. We contacted our colleagues in Japan and we are working with the Japanese authorities and trying to track the owner of this particular fishing boat."
Mr Hafner says some of the debris is expected to litter Hawaiian beaches and the West Coast of the United States within the next three years.