The effects of the 2011 tsunami in Japan continue until this day. Almost 300 different species have traveled from the waters of Japan to the coasts of Hawaii and the North America since the devastating tsunami, but they did not do it on their own.
Resilient Non-Native Species
Marine scientists from Oregon State University reported their findings in their paper published this week in Science. What they found was that since the Japan earthquake and tsunami in 2011, almost 300 non-native sea creatures have traveled across the North Pacific Ocean and made their way to the coasts of the North America and Hawaii.
These 289 creatures are mostly invertebrates and include the Asian amur sea star and the Asian shore crab. Amazingly, some of these creatures endured years of floating on tsunami debris, so much so that new species are still being detected in U.S. coasts even in 2017. What's more, 20 percent of them were still capable of reproducing upon discovery.
"One thing this event has taught us is that some of these organisms can be extraordinarily resilient. We first saw species from Japan arriving in Oregon, we were shocked. We never thought they could live that long, under such harsh conditions," said John Chapman of Oregon State University.
After the 2011 tsunami, debris from the event littered the oceans. These materials include wood and man-made materials such as crates, buoys, Styrofoam, and fiberglass, and their presence in the ocean allowed the Japanese sea creatures to survive on these so-called ocean rafts.
Between 2012 and 2014, wood from the destroyed homes carried with them wood-burrowing shipworms to Oregon and other locations. However, these shipworms destroy wood, which is why such debris and creatures ceased to land after 2014.
After the wood landings declined, researchers observed that it was non-biodegradable ocean rafts that allowed the transport and survival of the creatures for such a long time.
Biogeography And The Plastic Problem
Apart from the plastic materials that made its way into the oceans after the 2011 tsunami, 10 million tons of plastic wastes make its way to the oceans from almost 200 countries each year. That's a staggering amount of ocean waste that makes for stable ocean rafts for various creatures.
This new study shows that the problem with plastic wastes in the ocean is more complex than water pollution, which in itself is already a serious threat to marine life. By giving different species transport vectors to move to new habitats, researchers believe we could experience serious economic and environmental impacts that could come about from the proliferation of marine invasive species.
Photo: Oregon State University | Flickr