Plastic waste serves as ‘ocean raft’

Scientists find 289 live species on debris swept into Pacific by Japanese tsunami and carried to US

PLASTIC debris in the oceans is transporting creatures across the globe, scientists have warned.

For the first time in recorded history, researchers have discovered that entire communities of coastal species have crossed thousands of miles of water floating on makeshift rafts.

Between 2012 and 2017, nearly 300 species of marine animals arrived alive in North America from Japan, having travelled on crates and other objects released into the Pacific after the Japanese earthquake and tsunami of 2011.

Although the natural disaster was an extreme case, scientists say it is likely that many non-native species are travelling across thousands of miles of water on “ocean rafts” of marine plastic, carried by storm surges. “I didn’t think that most of these coastal organisms could survive at sea for long periods of time,” said Greg Ruiz, a marine biologist at the Smithsonian Environmental Research Center. “But in many ways they just haven’t had much opportunity in the past. Now, plastic can combine with tsunami and storm events to create that opportunity on a large scale.” John Chapman, a marine Some of the creatures that have survived despite a hazardous, long trip scientist at Oregon State University, added: “This has turned out to be one of the biggest, unplanned natural experiments in marine biology, perhaps in history.”

The 2011 tsunami swept millions of objects out to sea, from small pieces of plastic to entire fishing boats and even docks. Scientists began finding tsunami debris washing up in Hawaii and western North America in 2012, with living organisms still attached.

They detected 289 live species on debris originating from Japan. Molluscs such as mussels appeared most often of all invertebrates. Worms, crustaceans and bryozoans, which form underwater colonies, were close behind. Nearly twothirds of the species had never been seen on the US west coast. Scientists think the slower speed of ocean rafts may have allowed species to adjust to their new environments.

More than 10million tons of plastic waste enters the oceans each year. The research was published in Science.