NARRAGANSETT, R.I., Feb. 4, 2016 – It’s been nearly five years since an earthquake and tsunami ravaged Japan, killing nearly 16,000 residents. But what few people realize is that the catastrophe also swept tons of debris into the ocean.

Docks, baskets, buoys, and boats —mostly made of plastic, fiberglass and styrofoam—were ejected into the Pacific Ocean and turned into floating ecosystems with seaweeds, crabs, clams, worms, barnacles, fish and many other species.

Eventually, the debris landed on the coast of North America from Alaska to California, as well as in Hawaii, providing researchers with a unique opportunity to study how ocean rafting may transport invasive species.

One of those researchers is marine biologist James Carlton, who will present his discoveries during a talk Feb. 11 at the University of Rhode Island’s Coastal Institute. Free and open to the public, the talk will start at 4 p.m. in the Institute’s auditorium on the Graduate School of Oceanography’s Narragansett Bay campus, 215 South Ferry Road.

A world-renowned expert in aquatic invasive species, Carlton is a professor emeritus of marine science at Williams College and director emeritus of the Williams College Maritime Studies Program at Mystic Seaport. He has been studying the survival, dispersal and genetic makeup of the species that first arrived on American coasts in 2012. Since then, more than 400 objects have been studied with more than 330 living Japanese species aboard.

URI talked with Carlton recently about his work, climate change, New England marine bioinvasions and marine debris.

What kind of debris was swept into the ocean after the tsunami?

Virtually everything one might imagine from coastal towns and ports—what we call terrestrial-origin debris, including trees and wood from homes and businesses, as well as marine-origin debris, including thousands of small vessels, floats, crates and docks of all sizes.

What did beach walkers on an Oregon beach find?

Fourteen months after the tsunami, early morning strollers on a central Oregon beach found a huge dock washed ashore, which was then quickly traced to being lost March 11, 2011, from a Japanese port. State and other officials quickly moved to eradicate the more than 100 potentially invasive species on the dock. It cost more than $85,000 to remove the dock from the shore.

What kind of debris are you finding in New England and where is it coming from?

Our marine debris—consisting of every imaginable item made of plastics—comes largely from our own towns and cities and ocean-based activities, as did the debris on the West Coast before the tsunami. Locally generated debris can serve as a coastal dispersal mechanism for many non-native species. Ballast water is another mechanism that can disperse species along the coast and bring novel species from overseas. Ships take up ballast in a foreign port and discharge it in our ports. In recent years ships are required to release their foreign water on the high seas and refill with open ocean water, which contains species that do not survive in our coastal waters.

The Asian/Oriental shrimp and the British prawn are in New England waters. When did they get here and what’s their influence on the local environment?

Both shrimp species likely arrived in the 1990s and early 2000s, brought in with ballast water. We are studying what their impact may be on their prey and on our native shrimp.

Is climate change affecting our coastal ecosystem?

Yes, indeed. Warm-water southern species are steadily moving up our coasts into what were previously too-cold waters. Along our south Atlantic coastline this is known as Caribbean Creep—the novel and permanent presence of Caribbean species in Georgia, South Carolina, and elsewhere. Examples include large tropical barnacle Megabalanus coccopoma and the Caribbean crab Petrolisthes armatus.

For more information about the talk, please contact Meredith Haas at mmhaas@uri.edu or Rhode Island Sea Grant at 401-874-6805. The talk is sponsored by Rhode Island Sea Grant with support from the Coastal Institute, Graduate School of Oceanography and the College of the Environment and Life Sciences.

Pictured above: James Carlton, professor emeritus of marine sciences at Williams College and director emeritus of the Williams College Maritime Studies Program at Mystic Seaport. Photo by Anna Sawin.