A 25-foot-long chunk of fiberglass that likely belonged to a Japanese fishing boat was discovered thousands of miles away from its home on Thursday in the waters off the coast of Oregon.

Stowed away on board the flotsam were several live yellowtail jack fish, a species common to the ocean near Japan. Authorities suspect the boat was destroyed during the deadly earthquake and subsequent tsunami that ravaged eastern Japan four years ago.

The catastrophe killed more than 18,000 people and caused $300 billion worth of damage. It also unleashed an estimated five million tons of debris into the Pacific Ocean, the majority of which immediately sank to the bottom. The remainder still afloat is scattered throughout the Pacific, where it periodically washes up on U.S. beaches.

Oregon Parks and Recreation Department spokesperson Chris Havel said the state has seen plenty of refuse from the disaster over the past few years — including a 66-foot-long boat dock, a mannequin head and several other sea craft — but it's relatively rare to find animal life dwelling inside.

The debris was first spotted on Thursday evening a few miles from shore. A team of state agencies then intercepted it and dragged it into harbor after scientists determined that it was free of any invasive species.

The next step is to yank the wreckage out of the ocean, clean it off and try to discern some type of identifying marks, which will then be turned over to the Japanese consulate. Biologists have already transported the fish to an aquarium and collected algae samples in hopes of learning more about the boat's origins.

The wreckage is likely the remains of a 50-foot commercial fishing vessel called a trawler, which is designed to haul fish out of deeper waters, Havel said. Trawlers are one of the heavier models of commercial fishing boats, but Havel said the craft was not built to traverse distances anywhere close the 5,000-mile voyage that it inadvertently took.

"It's not like a big sturdy metal boat that was used to cross the ocean or anything," Havel told Mashable. "It was most likely used closer to the coast of Japan."

Havel speculated the shipwreck was likely swallowed up in a Pacific ocean current that spit it out off the coast of Oregon, but much of its story remains a mystery until experts are able to examine it.

"We really have no idea," Havel said. "We may never know what path it took to get here."