From Stephanie Pappas, LiveScience Senior Writer:

Oyster buoys and refrigerator parts set adrift by the 2011 Japan tsunami are now rolling in with the tide on Hawaii's beaches, a new field survey reveals.

Black oyster buoys and refrigerator parts — and even a full refrigerator — that trace back to Japan have shown up on the islands of Oahu and Kauai, said Nicholas Mallos, a conservation biologist and ocean debris specialist at the nonprofit Ocean Conservancy. Also on Oahu, researchers found a large 4-foot by 4-foot (1.2 by 1.2 meters) chunk of housing insulation framed in wood, a piece almost certainly sent into the sea by the devastating tsunami.

"These items have never before been seen on these beaches," Mallos told LiveScience.

The Japanese government has estimated the tsunami, which was triggered by an underwater earthquake in March 2011, swept about 5 million tons of wreckage out to sea. While 70 percent appears to have sunk offshore, the rest is floating in the Pacific Ocean. The first bit to show up in Hawaii, in September, was a barnacle-covered seafood storage bin.

Paradise of plastic

Exposed to ocean currents on every side, the Hawaiian Islands are a hotspot for Pacific junk. Some of this ocean litter originates from the fishing industry; most of the rest is consumer garbage from soda bottles, toys and other plastic goods, much broken down by the waves beyond recognition. [In Photos: Tsunami Debris & Ocean Trash in Hawaii]

At Kimalo Point on Hawaii's Big Island, tiny fragments of plastic penetrate as much as 3 feet (0.9 meters) below the beach surface.

"Many places on the beach, it's hard to differentiate the sand from the plastics on the surface," Mallos said.

The tsunami debris is different. For one thing, it tends to be larger, having only been in the ocean since March 2011, Mallos said. The debris also comes ashore in surprisingly homogenous waves. This summer, it was oyster buoys, Mallos said. Now, it's refrigerator parts.

The reason? Wind acts on similar objects in similar ways, according to research by Nikolai Maximenko of the University of Hawaii at Manoa's International Pacific Research Center. All of the tsunami debris went into the ocean at the same time, but some objects drift across the Pacific faster than others. That results in clusters of similar objects showing up in Hawaii and along the North American West Coast at the same time. [Tracking Tsunami Debris (Infographic)]

japan tsunami debris hawaii

Small plastic fragments are a huge problem on Hawaii's beaches. At Kamilo Point on the Big Island of Hawaii, where this photo was taken, such fragments may penetrate three feet down in the sand.

Debris hunt

Mallos and colleagues from the Japan Environmental Action Network, the Oceanic Wildlife Survey and the Japan Ministry of the Environment just completed a beach survey in Hawaii in search of this tsunami debris. They found about six or seven items, including the rusted Japanese refrigerator and buoys, which very likely came from the tsunami, Mallos said.

"We're not seeing a massive wave of debris wash onto the shore at one time, but right now, what it's been is a slow accumulation of debris here and there," he said. 

The tsunami debris is a problem, but it's part of a much bigger issue, Mallos said. Hawaii is awash with plastic trash from all over the world; the islands also neighbor the Great Pacific Garbage Patch, an area of the North Pacific where currents push masses of plastics into a suspended gyre of trash. Long story short: The oceans are a mess.

The Hawaii survey turned up masses of this typical ocean garbage, including fishing nets and traps, Mallos said. One of the stranger items was an intact plastic trashcan from Los Angeles County with "Heal the Bay" stickers on it. Heal the Bay is a nonprofit group that works to clean up California's Santa Monica Bay. In an unfortunate irony, one of the group's trashcans got into the ocean and floated some 2,500 miles (4,023 kilometers) to end up on a beach in Hawaii.

"It really highlights the fact that trash travels very far," Mallos said.

The average person can do their part to reduce ocean trash, Mallos said. Because consumer plastics are a huge part of the problem, resolving to use reusable grocery bags, coffee mugs and water bottles can keep one-time use plastics out of the oceans. The Ocean Conservancy has developed a free app, called Rippl, designed to nudge users into a more ocean-friendly routine by reminding them to take those sorts of small actions.

The problem of typical ocean trash is inextricably linked to the issue of tsunami debris, Mallos said. Tsunamis aren't preventable, but regular ocean litter is, he said.

"To the extent we can keep regular forms of ocean trash out of the ocean, in the face of disasters, the ocean becomes more resilient and better equipped to deal with the debris," he said.

The new survey was funded by the Environmental Restoration and Conservation Agency of Japan.

Follow Stephanie Pappas on Twitter @sipappas or LiveScience @livescience. We're also on Facebook & Google+.

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Earlier on HuffPost:

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  • This photo taken Sunday April 7, 2013 and provided by the Del Norte Triplicate shows a 20-foot fishing boat that washed up in Crescent City, Calif. (AP Photo/Del Norte Triplicate, Bryant Anderson)

  • A member of the Washington tsunami debris experts team stands on a dock Friday Dec. 21, 2012 that apparently floated from Japan after last year's tsunami and just washed ashore on a Washington beach near Forks Tuesday. (AP Photo/Washington Dept. of Fish & Wildlife)

  • Members of the Washington tsunami debris experts team inspect a dock Friday Dec. 21, 2012 that apparently floated from Japan after last year's tsunami and just washed ashore on a Washington beach near Forks Tuesday. (AP Photo/National Park Service)

  • In this file photo from Wednesday, June 6, 2012, a man looks at a 70-foot-long dock with Japanese lettering that washed ashore on Agate Beach in Newport, Ore. The West Coast is anticipating more debris from the 2011 Japanese tsunami to wash ashore this winter. Scientists expect the bulk of the tsunami debris to end up in the Pacific Northwest. (AP Photo/Rick Bowmer, File)

  • In this photo provided by the U.S. Coast Guard, Joshua Marvit, of the State of Hawaii Dept. of Health, tests a 16-foot skiff for radiation after the vessel was salvaged by the crew of the F/V Zephyr approximately 800 miles north of Honolulu, Friday, Oct. 5, 2012. The skiff was confirmed to have been debris from the 2011 Japan Tsunami by the Japanese Consulate, after they contacted the owner, through the Japanese Ministry of Foreign Affairs, and confirmed that they did not seek its return. (Petty Officer 2nd Class Eric J. Chandler, U.S. Coast Guard / AP)

  • In this photo provided by the U.S. Coast Guard, Joshua Marvit, of the State of Hawaii Dept. of Health, tests a 16-foot skiff for radiation after the vessel was salvaged by the crew of the F/V Zephyr approximately 800 miles north of Honolulu, Friday, Oct. 5, 2012. The skiff was confirmed to have been debris from the 2011 Japan Tsunami by the Japanese Consulate, after they contacted the owner, through the Japanese Ministry of Foreign Affairs, and confirmed that they did not seek its return. (Petty Officer 2nd Class Eric J. Chandler, U.S. Coast Guard / AP)

  • In this photo provided by the U.S. Coast Guard, Joshua Marvit, of the State of Hawaii Dept. of Health, tests a 16-foot skiff for radiation after the vessel was salvaged by the crew of the F/V Zephyr approximately 800 miles north of Honolulu, Friday, Oct. 5, 2012. The skiff was confirmed to have been debris from the 2011 Japan Tsunami by the Japanese Consulate, after they contacted the owner, through the Japanese Ministry of Foreign Affairs, and confirmed that they did not seek its return. (Petty Officer 2nd Class Eric J. Chandler, U.S. Coast Guard / AP)

  • In this photo taken June 20, 2012 and provided courtesy of the National Oceanic and Atmospheric Administration, University of Alaska student Derek Chamberlin stands atop a large ship's mooring buoy, found by NOAA marine debris scientists at Whale Bay, North Cape on Baranof Island during a recent survey of southeast Alaska beaches for marine debris. (AP Photo/NOAA, Jacek Maselko)

  • This image provided by National Oceanic and Atmospheric Administration shows a 20-foot, open boat found beached Friday June 15, 2012 on Washington's Benson Beach at Cape Disappointment State Park festooned with hundreds of what state Fish and Wildlife officials said are gooseneck barnacles. (AP Photo/NOAA)

  • A piece of debris is washed up on a beach in Ocean Shores, Wash., on Monday, June 18, 2012. While it is unknown if this particular item is from the tsunami, Washington Gov. Chris Gregoire announced Monday a state plan to address tsunami debris that reaches the state's coast from Japan but stressed that federal help is needed.. (AP Photo/Rachel La Corte)

  • This photo taken June 18, 2012 and provided by the National Oceanic and Atmospheric Administration shows a black buoy at a beach on the south side of Noyes Island, east of Cape Addington where scientists have found it and others on a recent survey of southeast Alaska shorelines. (AP Photo/NOAA)

  • This photo taken Wednesday, June 6, 2012 and supplied by the Oregon Department of Parks and Recreation, shows a large dock that washed ashore early Tuesday on Agate Beach, a mile north of Newport, Ore. The nearly 70-foot-long dock was torn loose from a fishing port in northern Japan by last year's tsunami and drifted across thousands of miles of Pacific Ocean, a Japanese Consulate official said Wednesday. (AP Photo/Oregon Parks and Recreation)

  • In this photo taken by Canadian Peter Mark in the end of April, 2012, and released on Wednesday, May 2, a Harley-Davidson motorbike lies on a beach in Graham Island, western Canada. Japanese media say the motorcycle lost in last year's tsunami washed up on the island about 6,400 kilometers (4,000 miles) away. The rusted bike was originally found by Mark in a large white container where its owner, Ikuo Yokoyama, had kept it. The container was later washed away, leaving the motorbike half-buried in the sand. Yokoyama, who lost three members of his family in the March 11, 2011, tsunami, was located through the license plate number, Fuji TV reported Wednesday. (AP Photo/Kyodo News, Peter Mark)

  • In a photo provided by the U.S. Coast Guard the unmanned Japanese fishing vessel Ryou-un Maru dirfts northwest in the Gulf of Alaska approximately 164 miles southwest of Baranof Island Wednesday April 4, 2012. The vessel has been adrift since it was launched by the tsunami caused by the magnitude-9.0 earthquake that struck Japan last year. The Coast Guard is monitoring the vessel, which is currently considered a hazard to navigation. (AP Photo/Petty Officer 1st Class Sara Francis, U.S. Coast Guard)

  • In this April 21, 2012 photo released by The Baxters via Kyodo News, David and Yumi Baxter hold a soccer ball and a volleyball which David found, at their house in the suburbs of Anchorage, Alaska. Kyodo News agency says the teenage owner of the soccer ball that apparently floated across the Pacific Ocean after last year's tsunami is surprised and thankful the ball - which had his name written on it - was found in Alaska. (AP Photo/The Baxters via Kyodo News)

  • Japanese Float Tsunami Debris

    This May 28, 2012 photo provided by Chris Pallister shows a Japanese float is collected on the shore of Montague Island near Seward, Alaska. More than a year after a tsunami devastated Japan, killing thousands of people and washing millions of tons of debris into the Pacific Ocean, neither the U.S. government nor some West Coast states have a clear plan for how to clean up the rubble that floats to American shores. (AP Photo/Chris Pallister)

  • Peter Clarkson

    In this April, 17, 2012, photo, artist Peter Clarkson poses with a portion of a totem pole that he has been building in Tofino, British Columbia. Clarkson made the pole with what he believes are tsunami-related Japanese floats, barrels and Styrofoam. While yet to be raised, the totem links Japan, First Nations and non-First Nations cultures and raises awareness about the ongoing problem of ocean garbage, said Clarkson. (AP Photo/The Canadian Press, Jonathan Hayward)

  • In this Dec. 20, 2011 photo provided by Dave Kubiak, Alexus Kwachka holds a yellow float in Kodiak, Alaska. The float, along with 6 others, have been identified as coming from oyster farms in Japan after the tsunami. (AP Photo/ Dave Kubiak)

  • Japanese Float Tsunami Debris

    In this June 6, 2012 photo provided by Chris Pallister, debris is strewn across the shore of Montague Island near Seward, Alaska. More than a year after a tsunami devastated Japan, killing thousands of people and washing millions of tons of debris into the Pacific Ocean, neither the U.S. government nor some West Coast states have a clear plan for how to clean up the rubble that floats to American shores. (AP Photo/Chris Pallister)

  • Japanese Float Tsunami Debris

    In this June 6, 2012 photo provided by Ryan Pallister, Patrick Chandler removes tsunami debris on Montague Island near Seward, Alaska. More than a year after a tsunami devastated Japan, killing thousands of people and washing millions of tons of debris into the Pacific Ocean, neither the U.S. government nor some West Coast states have a clear plan for how to clean up the rubble that floats to American shores. (AP Photo/Gulf of Alaska Keeper, Ryan Pallister)

  • This image provided by National Oceanic and Atmospheric Administration shows a 20-foot, open boat found beached Friday June 15, 2012 on Washington's Benson Beach at Cape Disappointment State Park festooned with hundreds of what state Fish and Wildlife officials said are gooseneck barnacles. Officials are warning the public to stay clear, just in case the boat might harbor any invasive plant or animal species. State fish and wildlife personnel will work on that assessment, the spokesman said. The National Oceanic and Atmospheric Administration has taken information written on the boat and is working with the Japanese consulate in Seattle to determine whether it came from Japan and, if so, whether it might have gone through the 2011 tsunami, Washington state Ecology Department spokesman Curt Hart said. (AP Photo/NOAA)

  • In this photo provided by the U.S. Coast Guard, the derelict Japanese fishing vessel RYOU-UN MARU drifts more than 125 miles from Forrester Island in southeast Alaska where it entered U.S. waters March 31, 2012. The vessel has been adrift since it was launched by a tsunami caused by the magnitude-9.0 earthquake that struck Japan last year. (AP Photo/U.S. Coast Guard)

  • In this photo provided by the U.S. Coast Guard, a plume of smoke rises from a derelict Japanese ship after it was hit by canon fire by a U.S. Coast Guard cutter on Thursday, April 5, 2012, in the Gulf of Alaska. The Coast Guard decided to sink the ship dislodged by last year's tsunami because it was a threat to maritime traffic and could have an environmental impact if it grounded. (AP Photo/U.S. Coast Guard, Petty Officer 2nd Class Charly Hengen)

  • In this photo provided by the U.S. Coast Guard, a plume of smoke rises from the derelict Japanese ship Ryou-Un Maru after it was hit by canon fire by a U.S. Coast Guard cutter on Thursday, April 5, 2012, in the Gulf of Alaska. The Coast Guard decided to sink the ship dislodged by last year's tsunami because it was a threat to maritime traffic and could have an environmental impact if it grounded. (AP Photo/U.S. Coast Guard)

  • A rust-encrusted Harley-Davidson motorcycle, shown in this undated handout photo by Peter Mark, made buoyant by the sea container in which it was stored, washed up on an island off the coast of British Columbia after it was lost in last year's tsunami in Japan, about 6,400 kilometres away. (AP Photo/CBC-Peter Mark, The Canadian Press)

  • Steve Drane, Ralph Tieleman

    Ralph Tieleman, second left, dealership owner Steve Drane, and onlookers look at Ikuo Yokoyama's 2004 Harley-Davidson Night Train that was swept to sea during the Japanese tsunami, in Langford, British Columbia, Sunday May 6, 2012. The motorcycle is nearing the final stretch in its journey home. (AP Photo/The Canadian Press, Chad Hipolito)

  • In this undated photo taken before March 11, 2011 by its owner Ikuo Yokoyama and distributed by Japan's Kyodo News, a Harley-Davidson sits in the garage in Kakuda, Niyagi Prefecture, northern Japan. Japanese media said Wednesday, May 2, 2012, the motorcycle lost in March 11, 2011 tsunami washed up on a Canadian island about 6,400 kilometers (4,000 miles) away. (AP Photo/Ikuo Yokoyama via Kyodo News)

  • Massive dock, potentially tsunami debris, hits Oregon Coast

    Scientists from OSU and BLM agents inspect a massive dock with Japanese lettering that washed ashore on Agate Beach on Wednesday, June 6, 2012 a mile north of Newport, Ore. Evidence is mounting that the nearly 70-foot floating dock that washed ashore came from an area of Japan devastated by last year's tsunami. (AP Photo/The Oregonian, Thomas Boyd)

  • This photo taken Wednesday, June 6, 2012 and supplied by the Oregon Department of Parks and Recreation, shows a large dock that washed ashore early Tuesday on Agate Beach, a mile north of Newport, Ore. The nearly 70-foot-long dock was torn loose from a fishing port in northern Japan by last year's tsunami and drifted across thousands of miles of Pacific Ocean, a Japanese Consulate official said Wednesday.(AP Photo/Oregon Parks and Recreation)

  • A man looks at the massive dock with Japanese lettering that washed ashore on Agate Beach Wednesday, June 6, 2012, in Newport, Ore. A nearly 70-foot-long dock that floated ashore on an Oregon beach was torn loose from a fishing port in northern Japan by last year's tsunami and drifted across thousands of miles of Pacific Ocean, a Japanese Consulate official said Wednesday. (AP Photo/Rick Bowmer)

  • This photo, taken by the Oregon Park and Recreations Department Thursday, June 7, 2012, shows an exotic pink Japanese acorn barnacle attached to a dock float that washed up on Agate Beach Tuesday near Newport, Ore. State authorities are considering how to dispose of the millions of marine creatures that hitchhiked across the Pacific Ocean aboard the dock float torn loose from a Japanese fishing port by the 2011 tsunami so they will not compound the problem of invasive species.(AP Photo/Oregon Parks and Recreation Department, ho)

  • This photo, taken by the Oregon Park and Recreations Department Thursday, June 7, 2012, shows exotic mussels attached to a dock float that washed up on Agate Beach Tuesday near Newport, Ore. State authorities are considering how to dispose of the millions of marine creatures that hitchhiked across the Pacific Ocean aboard the dock float torn loose from a Japanese fishing port by the 2011 tsunami so they will not compound the problem of invasive species.(AP Photo/Oregon Parks and Recreation Department, ho)

  • This photo, taken by the Oregon Park and Recreations Department Thursday, June 7, 2012, shows an invasive specie commonly known as "wakame" attached to a dock float that washed up on Agate Beach Tuesday near Newport, Ore. State authorities are considering how to dispose of the millions of marine creatures that hitchhiked across the Pacific Ocean aboard the dock float torn loose from a Japanese fishing port by the 2011 tsunami so they will not compound the problem of invasive species.(AP Photo/Oregon Parks and Recreation Department, ho)

  • This photo, taken by the Oregon Park and Recreations Department Thursday, June 7, 2012, shows an exotic mussel attached to a dock float that washed up on Agate Beach Tuesday near Newport, Ore. State authorities are considering how to dispose of the millions of marine creatures that hitchhiked across the Pacific Ocean aboard the dock float torn loose from a Japanese fishing port by the 2011 tsunami so they will not compound the problem of invasive species.(AP Photo/Oregon Parks and Recreation Department, ho)

  • This photo taken Wednesday, June 6, 2012 and supplied by the Oregon Department of Parks and Recreation, shows the metal plaque from a large dock that washed ashore early Tuesday on Agate Beach, a mile north of Newport, Ore. The nearly 70-foot-long dock was torn loose from a fishing port in northern Japan by last year's tsunami and drifted across thousands of miles of Pacific Ocean, a Japanese Consulate official said Wednesday.(AP Photo/Oregon Parks and Recreation)

  • In this Thursday, June 7, 2012 photo proivded by the Oregon Park and Recreations Department, unidentified workers shovel debris from the top of a dock float torn loose from a Japanese fishing port by the 2011 tsunami that washed up Tuesday on Agate Beach near Newport, Ore. Workers with shovels, rakes and other tools first scraped the structure clean, then briefly used low-pressure torches to sterilize the dock that was. (AP Photo/Oregon Parks and Recreation Department)

  • The surf pounds against the massive dock that washed ashore on Agate Beach Wednesday, June 6, 2012, in Newport, Ore. A nearly 70-foot-long dock that floated ashore on an Oregon beach was torn loose from a fishing port in northern Japan by last year's tsunami and drifted across thousands of miles of Pacific Ocean, a Japanese Consulate official said Wednesday. (AP Photo/Rick Bowmer)

  • In this Thursday, June 7, 2012 photo proivded by the Oregon Park and Recreations Department, an unidentified worker burns off debris from of a dock float torn loose from a Japanese fishing port by the 2011 tsunami that washed up Tuesday on Agate Beach near Newport, Ore. Workers with shovels, rakes and other tools first scraped the structure clean, then briefly used low-pressure torches to sterilize the dock. (AP Photo/Oregon Parks and Recreation Department)

  • Raw Video: Coast Guard Sinks Ghost Ship

    The U.S. Coast Guard used cannon fire to sink an empty Japanese ship in the Gulf of Alaska. The "ghost ship" drifted across the Pacific after last year's tsunami. (April 6)