Invasive Species Are Still Hitching Rides on Tsunami Debris

Six years after the devastating earthquake and tsunami in Japan, debris is still working its way across the Pacific, and it’s carrying an unwelcome payload: invasive species that could run rampant if they get a foothold on foreign shores.

A new paper in ”Science explores research on 289 organisms that reached the U.S. via marine debris from the tsunami, in what the authors call “tsunami-driven rafting.”

Marine debris has been circulating the world’s oceans for millions of years, and taking organisms with it — so what’s the big deal here?

Researchers found that many organisms were arriving on non-biodegradable materials like plastic, making it easier to travel long distances. Making it across the Pacific used to require an extraordinary combination of circumstances — now all that’s needed is time and a milk jug.

Scientists point out another issue: “expanding shoreline infrastructure.”

Humans have always settled on the shore to have easy access to shipping lanes and plentiful food, but human civilizations are getting denser — and they’re exerting more pressure on the surrounding environment. Instead of fishing villages filled with wooden boats and glass fishing floats, humans are building massive cities, which come with plastic, styrofoam and a host of other items that don’t break down readily.

That’s bad enough, but students of climate change already know there’s another issue: Thanks to storms of increasing severity and creeping sea levels, that same infrastructure is also under threat.

This problem is magnifying the issue, and researchers say it could lead to an uptick of invasive species traveling the seven seas. Invasive organisms may flourish thanks to lack of predators, and that absence of natural checks can allow them to choke out endemic species, particularly if they’re vulnerable.

Even with much in their favor, an organism’s ability to survive a journey of several years is pretty impressive. Some fish were trapped inside entire boats that floated away, along with mollusks and crustaceans.

Over time, a changing climate and a growing amount of trash entering the ocean could result in less diversity in marine ecosystems all over the world. Understanding how and where organisms travel can help researchers working to preserve biodiversity, and it might just encourage a few consumers to think about incorporating more reusable items into their lives.

Scientists count on reports about marine debris from citizens. The National Oceanic and Atmospheric Administration maintains a page with information about what you should do if you identify debris from the tsunami — and no, it’s not “take it home for a cool story to tell the grandkids.”

Instead, you need to report the item so it can be added to the growing database of material that helps researchers understand ocean currents and the lingering aftereffects of the tsunami. This also allows scientists to determine whether any unwelcome guests have hitched a ride, so they can be removed and destroyed, keeping them out of vulnerable ecosystems.

I’ll leave you with a little oceanography trivia. Marine debris is material that washes into the ocean — like pieces of homes destroyed by the tsunami. Flotsam refers to wreckage from sunken ships. And jetsam describes material thrown overboard, usually to reduce the weight of a vessel. Historically and now, these aren’t just semantic distinctions, because they can affect the legal status of material that washes ashore.

Photo credit: Oregon Department of Fish and Wildlife


Marie W
Marie W11 months ago

Thank you

heather g
heather gabout a year ago

It's difficult to understand why people don't report all such incidents to authorities - unfortunately, many people have no concept of the impact of their actions.

Carl R
Carl Rabout a year ago


Aaron F
Past Member about a year ago

As they have throughout the millenia......

Georgina M
Georgina Elizab Mabout a year ago


Winn A
Winn Adamsabout a year ago


Winn A
Winn Adamsabout a year ago

Petition Signed

Leo C
Leo Custerabout a year ago

Thank you for sharing!

Debbi W
Debbi Wabout a year ago

Jenn C., there are native species, which are natural to an area. Invasive species are species out of their native area and can cause a lot of damage because in a foreign area they have no natural enemies to balance them in nature.

There is an invasive variety of ivy in western Oregon. Most poisonous chemicals have no effect on it. You have to dig it out by the root and be careful not to leave as much as a leaf, which could root. One patch doesn't sound that bad does it? Imagine a whole yard or imagine it taking over forested land. It's a real nightmare.

David C
David Cabout a year ago