"Necessity is the mother of invention"--that old maxim proved correct in the case of a group of Kyushu-based researchers who made it their mission to come up with an effective countermeasure to oil slicks that ooze from grounded tankers. Researchers at the Oita Industrial Research Institute in Oita Prefecture have succeeded in developing an effective oil-absorbing mat and fence made from the bark of Japanese cedar. Recently, they demonstrated the effectiveness of their inventions at an experimental facility in Imari, Saga Prefecture, Japan. A thick layer of heavy oil covered the surface of the water in the facility's 30-meter-long experimental tank. A bag-like net, one meter wide by six meters long and filled with cedar bark bits, was then cast into the tank. As the net was pulled out, it trapped the oil between the cedar bits and on their surfaces, which were soon stained black.