Researchers from Williams College have found that the deadly tsunami in 2011 brought hundreds of aquatic Japanese species to the U.S. coastline, a new study published in the journal Science reports.
The foreign animals moved across the Pacific Ocean when a huge earthquake off the coast of north-eastern Japan caused a giant tsunami. That event displaced a wide number of species, including certain types of mussels and starfish. Scientists are surprised so many animals survived the long journey, and new species are still washing up this year.
“Many hundreds of thousands of individuals were transported and arrived in North America and the Hawaiian islands – most of those species were never before on our radar as being transported across the ocean on marine debris,” lead author James Carlton, a professor at Williams College, told BBC News.
So far, researchers have uncovered 289 foreign species. Mussels are the most common, but there are large numbers of crabs, clams, and sea anemones as well. In addition, the team believes there are many other animals that made the journey that have not been found yet. While none of the foreign animals have been established as invasive threats, scientists believe it is just a matter of time before that situation occurs.
Most tsunamis do not spur such large amounts of movement. However, the 2011 event is different because it washed away a large number of products that do not decompose, such as plastic and fiberglass. This gave many animals a way to stay afloat in the open water. In addition, as such objects tend to drift slowly, they also gave the species time to gradually adjust to their new environment.
This research is important because scientists are currently concerned with the amount of plastic in the oceans. As climate change continues to bring about extreme weather events, it is likely the number of invasive or foreign aquatic species will increase around the world.
“This is a really nice example of the very important role that long-distance dispersal in general, and rafting in particular, plays in structuring global patterns of biodiversity,” said Ceridwen Fraser, a marine biologist at Australian National University who was not involved with this research, according to The Washington Times.