On March 11, 2011, a deadly tsunami, triggered by a magnitude 9.0 earthquake, struck the north-eastern coast of Japan causing the Fukushima power station disaster along with other major damage. Since that date, almost 300 different species of marine life have made their way across the Pacific Ocean to the west coast of the U.S.A.

Longest ever maritime migration

Experts are now saying this is the longest ever maritime migration in recorded history as around 1 million Japanese marine creatures, including sea slugs, sea worms, and crustaceans, have traveled an amazing 4,800 miles clinging to, and hanging out on, a huge flotilla of debris from the tsunami.

In a study published in Science this week, John Chapman of Oregon State University said it had turned into one of the largest unplanned natural experiments in the field of marine biology, and probably in history itself.

According to experts, the tsunami generated some five million tons of debris from three Japanese prefectures affected by the incident – Fukushima, Miyagi, and Iwate. While around 70 percent sank to the ocean floor, some of the marine creatures traveled across the ocean as hitchhikers, on a series of docks, buoys, boats and other buoyant objects.

289 marine species arrive from Japan

According to the BBC, the study notes that between June 2012 and February 2017 at least 289 marine species from Japan, attached to some 600 pieces of buoyant debris, were washed up on the U.S.

coast, ending up on beaches in Alaska, California, Hawaii, Oregon, and Washington, along with British Columbia in Canada. Around two-thirds of the species had never before been seen on the U.S. west coast. On top of this, the experts reckon some of these species reproduced while they were drifting from Japan to the U.S.A.

According to a marine science professor, James Carlton of Williams College in Massachusetts, the diversity of the marine creatures was “jaw-dropping.” He said the wide variety of marine species included corals, mollusks, crabs, sea anemones, among other species, adding it was a “cross-section of Japanese fauna.” Carlton mentioned that last year a Japanese boat made its way to Oregon with 20 Japanese native fish inside, some of which can be viewed at a local aquarium.

Marine creatures hitchhiked on plastic and fiberglass objects

Most of the marine creatures were attached to, or riding in, boats, crates, buoys and other items made from fiberglass, plastic and similar materials that do not decompose. However, Greg Ruiz, a co-author of the study and a marine biologist with the Smithsonian Environmental Research Center, said he wouldn’t have thought most of these organisms could survive for long periods at sea.

He added the organisms hadn’t had the opportunity in the past, but these days plastic, combined with storm and tsunami effects, gave the creatures the opportunity on a really large scale.

According to a report by the New York Times, it now remains for experts to find out if the Japanese marine creatures have colonized on the west coast of the U.S.A. This is likely and which could pose a threat to the native life, but they say it will take several years to confirm this.