The Department of Land and Natural Resources has confirmed that boat debris found at Kahana Bay a week after Thanksgiving came from the 2011 Japan tsunami.

The 20-foot boat was reportedly seen floating intact in the bay on Nov. 29. It apparently broke into pieces the following day on rocks on the bay’s outer edge.

Recovered pieces of the stern included Japanese registration numbers.

The Japanese government confirmed that the numbers match a boat swept to sea in the aftermath of the magnitude-9.0 quake off Japan in March 2011.

The debris has since been properly disposed of, department spokeswoman Deborah Ward said Tuesday.

The boat is the fourth confirmed piece of tsunami marine debris to have reached Hawaii shores.

Ward said the department is awaiting confirmation on whether a boat recovered at Punaluu also is debris from the tsunami. The boat, approximately 24 feet long, was discovered by a Puna­luu family and reported to the department on Dec. 23.

Experts found gooseneck barnacles and several types of crabs on the boat, similar to organisms found on other tsunami marine debris. Green mussels native to Japan were also found.

The boat is secured at the Keehi Small Boat Harbor, where it will remain until salvage claims are filed, Ward said.

The department recently recovered a 20-foot-long wooden object floating off of Ewa Beach Park. It was about 12 feet wide and 6 inches thick, contained metal reinforcing bars, and posed a hazard to navigation and also possibly to the environment, Ward said.

It is unknown whether it is tsunami debris, she said.