The 2011 Japanese tsunami washed an estimated 5 million tons of debris into the ocean, and two years later, one small chunk of that is being dismantled in Washington state. Workers have begun taking apart a 185-ton, 65-foot-long dock that washed ashore in a hard-to-reach area of Olympic National Park, reports LiveScience. One reason they can't just leave it: The dock is encased in concrete but has a Styrofoam material inside, which could spill out and be ingested by fish and birds. The good news is that tests show the dock isn't radioactive. The worrisome news is that it might very well have provided transport across the ocean for some invasive species stuck to its side. Time will tell.