This time, it's NOT a result of the 2011 Japanese tsunami. A disintegrating dock that washed up on a tiny island near Kodiak is polluting the beach and nearby waters with chunks of Styrofoam. The Kodiak Daily Mirror reports  that the exact origins of the dock are unknown but that it could be up to 50 years old.
The Alaska Department of Environmental Conservation and [Island Trails Network] were initially worried that if the dock was Japanese tsunami debris it could bring new species to the region and cause a threat to the environment.
They were able to determine that it was not Japanese tsunami debris based on some of the items they found onboard, including a cargo net and a Dungeness crab pot. There was also grass growing in the cracks of the dock’s wood surface. The grass is a species found on Kodiak shores.
Cleanup of the quickly disintegrating foam would be difficult and therefore costly, officials told the Daily Mirror. The mystery dock is sitting on land owned by the Alaska Maritime National Wildlife Refuge. Cleanup volunteers are being sought.