Lessons Learned in Detecting Japan Tsunami Marine Debris at Sea

A new report issued in January by the NOAA Marine Debris Program says one of the biggest lessons learned from tracking marine debris from the Japanese tsunami is a better understanding of use of remote-sensing technology.

Researchers now have a better base of understanding to move forward with using remote-sensing technologies for at-sea detection of debris, but the report emphasizes that the human eye is critical to the effort, both in finding debris and in providing a “ground-truth” comparison to what can be detected from the air.

The complete report is online at http://marinedebris.noaa.gov/sites/default/files/JTMD_Detection_Report.pdf

Marine debris is very small compared to the North Pacific, so we need to try as many different methods as possible to locate it,” said Peter Murphy, regional coordinator for the NOAA Marine Debris Program. “If you shrank the North Pacific to the size of a football field, even a large object like the Misawa dock is still equivalent to the width of a human hair, and it would be a moving hair.

“We learned lessons about what works and what doesn’t work, so now we have a tool kit of knowledge on the mix of techniques and when to use them in future projects and responses,” he said.

Before the tsunami, some of the detection technologies, including several types of satellite sensors, had not been used before to find marine debris or were in early stages of testing. Because of the extensive efforts and renewed interest in at-sea detection during the Japan tsunami marine debris response, the marine debris community learned more about marine debris behavior and movement and has advanced the state of knowledge on detection of debris at sea, Murphy said.

Federal, state and local partners focused on finding marine debris from the Japan tsunami through several detection methods, including observations from aircraft, unmanned aircraft systems, vessels, shoreline observers, and satellites. NOAA paired detection with modeling in order to focus detection resources on areas where the debris was most likely to be located, given the large area of ocean where the debris dispersed.