The Ocean Voyages Institute recently completed a trip off the North American coast as it sailed from San Francisco to British Columbia, where it is scheduled to attend a maritime festival in Richmond, south of Vancouver, this weekend.
The group's ship, a 46-metre, twin-masted sailing vessel named the Kaisei, encountered debris from the March 2011 earthquake and tsunami roughly 500 kilometres off the coast of Oregon and Washington state, said Mary Crowley, who founded the Ocean Voyages Institute.
Crowley, who wasn't on the ship for the most recent voyage, said the Kaisei found part of a dock and other smaller debris that experts on board believed were swept into the ocean by the tsunami.
She said the tsunami debris poses a significant risk to the Pacific Ocean and the animals that inhabit it, but she noted it pales in comparison to the vast amount of debris — much of it floating plastic garbage — already in the world's oceans.
"The tsunami debris adds this whole other element of knowing where it all went into the ocean and where it's going and how it's spreading, but in fact every day, all over the Pacific basin, debris is going into the ocean," Crowley told reporters Wednesday.
"So the tsunami debris shows us graphically what's happening."
Specifically, she pointed to a massive field of floating plastic often referred to as the "Great Pacific Garbage Patch," which is believed to make up an area roughly the size of Texas.
The "Great Pacific Garbage Patch" is located between Hawaii and California in the northern Pacific Ocean, where millions of small bits of plastic have gathered in a vortex of ocean currents known as a gyre. Some of the debris from the tsunami is expected to join the garbage patch.
Crowley said her group has visited the area, most recently in 2009 and 2010, when the Kaisei found that sea life including fish and jellyfish were eating the plastic debris.
She said governments around the world aren't doing enough to find ways to clean up that debris field, nor are they taking adequate steps to prevent plastic from entering the ocean in the first place.
"I think that all governments need to step up and try to keep debris out of the ocean, and contribute to clean up efforts," she said.
Crowley said the international community should set up a system for cleaning up debris immediately after a disaster such as a tsunami, rather than waiting until wreckage has moved out to sea and spread out over wide distances.
She also said governments should brainstorm for ways to clean up ocean debris, such as paying fishermen to collect it.
But equally important, said Crowley, is ensuring that plastic doesn't enter the ocean in the first place. The responsibility for that, she said, rests with members of the public, governments and corporations, such as through reducing their reliance on plastic and recycling what they use.
"Every individual, every community, every company can make a difference in helping the debris issue," she said.