Japanese marine animals have hitched a ride all the way to the United States with unlikely help from plastic garbage. The March 2011 earthquake and tsunami dumped debris into the ocean, and now, several years later, scientists have recorded almost 300 marine animal species in Hawaii and North America that rode in on crates, buoys, vessels, and trash. Scientists didn’t think organisms passively drifted on debris across the ocean, according to marine scientist John Chapman of Oregon State University. He said, “This has turned out to be one of the biggest, unplanned, natural experiments in marine biology, perhaps in history.”
You knew plastic trash was polluting the oceans, but you probably didn’t know it was transporting non-native species across them. Neither did many scientists, who were surprised to discover Japanese species landing alive in North America and Hawaii. Researchers didn’t expect organisms to live through the trip across the North Pacific Ocean – and many species have lived four or more years longer than any previous records of organisms living on ocean rafts.
In the beginning, wood released in the natural disasters showed up in Oregon with shipworms inside, but after 2014, wood landings plummeted, and researchers realized non-biodegradable trash like plastic, styrofoam, and fiberglass was allowing non-native species to travel and survive for so long.
So far, scientists haven’t found any Japanese species established on the West Coast, but Chapman said that can take years to happen. He said, “One thing this event has taught us is that some of these organisms can be extraordinarily resilient…It would not surprise me if there were species from Japan that are out there living along the Oregon coast. In fact, it would surprise me if there weren’t.” Oregon State University marine scientist Jessica Miller said out of the species that arrived in 2017, almost 20 percent were capable of reproducing.
James Carlton of Williams College, who was the lead author on a study published today in Science, said, “These vast quantities of non-biodegradable debris, potentially acting as novel ocean transport vectors, are of increasing concern given the vast economic cost and environmental impacts documented from the proliferation of marine invasive species around the world.”
Chapman and Miller were co-authors of the study, along with six other scientists from institutions around the United States.