Vehicle parts and other debris washed away by the tsunami in March 2011 have created a breeding reef of sorts for a variety of seabed creatures.
The Japan Agency for Marine-Earth Science and Technology in late February used an unmanned vehicle to survey the seafloor off the Sanriku coast of northeastern Japan. Images obtained showed populations of brittle stars, feather stars and other organisms crowding around car bumpers and fishing nets at a depth of 540 meters.
Katsunori Fujikura, a JAMSTEC principal scientist of deep-sea biology, said much of the tsunami rubble has accumulated on valley-shaped terrain.
Polychaetes and other creatures that like sticking to hard objects were found swarming around the debris for the first time in February and March 2012. Their numbers increased in each of the subsequent surveys taken about once a year, Fujikura said.
Those creatures in turn feed other organisms, such as the broadfin thornyhead, a high-grade fish.