Where Are the Pacific Garbage Patches Located?

Microplastics, small plastics less than 5 millimeters long, are an increasingly common type of marine debris found in the water column (including the “garbage patches”) and on shorelines around the world. Based on research to date, most commonly used plastics do not fully degrade in the ocean and instead break down into smaller and smaller pieces. (NOAA Marine Debris Program)

The Pacific Ocean is massive. It’s the world’s largest and deepest ocean, and if you gathered up all of the Earth’s continents, these land masses would fit into the Pacific basin with a space the size of Africa to spare.

While the Pacific Ocean holds more than half of the planet’s free water, it also unfortunately holds a lot of the planet’s garbage (much of it plastic). But that trash isn’t spread evenly across the Pacific Ocean; a great deal of it ends up suspended in what are commonly referred to as “garbage patches.”

A combination of oceanic and atmospheric forces causes trash, free-floating sea life (for example, algae, plankton, and seaweed), and a variety of other things to collect in concentrations in certain parts of the ocean. In the Pacific Ocean, there are actually a few “Pacific garbage patches” of varying sizes as well as other locations where marine debris is known to accumulate.

The Eastern Pacific Garbage Patch (aka “Great Pacific Garbage Patch”)

In most cases when people talk about the “Great Pacific Garbage Patch,” they are referring to the Eastern Pacific garbage patch. This is located in a constantly moving and changing swirl of water roughly midway between Hawaii and California, in an atmospheric area known as the North Pacific Subtropical High.

NOAA National Weather Service meteorologist Ted Buehner describes the North Pacific High as involving “a broad area of sinking air resulting in higher atmospheric pressure, drier warmer temperatures and generally fair weather (as a result of the sinking air).”

This high pressure area remains in a semi-permanent state, affecting the movement of the ocean below. “Winds with high pressure tend to be light(er) and blow clockwise in the northern hemisphere out over the open ocean,” according to Buehner.

As a result, plastic and other debris floating at sea tend to get swept into the calm inner area of the North Pacific High, where the debris becomes trapped by oceanic and atmospheric forces and builds up at higher concentrations than surrounding waters. Over time, this has earned the area the nickname “garbage patch”—although the exact content, size, and location of the associated marine debris accumulations are still difficult to pin down.

This map is an oversimplification of ocean currents, features, and areas of marine debris accumulation (including “garbage patches”) in the Pacific Ocean. There are numerous factors that affect the location, size, and strength of all of these features throughout the year, including seasonality and El Nino/La Nina. (NOAA Marine Debris Program)

The Western Pacific Garbage Patch

On the opposite side of the Pacific Ocean, there is another so-called “garbage patch,” or area of marine debris buildup, off the southeast coast of Japan. This is the lesser known and studied, Western Pacific garbage patch. Southeast of the Kuroshio Extension (ocean current), researchers believe that this garbage patch is a small “recirculation gyre,” an area of clockwise-rotating water, much like an ocean eddy (Howell et al., 2012).

North Pacific Subtropical Convergence Zone

While not called a “garbage patch,” the North Pacific Subtropical Convergence Zone is another place in the Pacific Ocean where researchers have documented concentrations of marine debris. A combination of oceanic and atmospheric forces create this convergence zone, which is positioned north of the Hawaiian Islands but moves seasonally and dips even farther south toward Hawaii during El Niño years (Morishige et al., 2007, Pichel et al., 2007). The North Pacific Convergence Zone is an area where many open-water marine species live, feed, or migrate and where debris has been known to accumulate (Young et al. 2009). Hawaii’s islands and atolls end up catching a notable amount of marine debris as a result of this zone dipping southward closer to the archipelago (Donohue et al. 2001, Pichel et al., 2007).

But the Pacific Ocean isn’t the only ocean with marine debris troubles. Trash from humans is found in every ocean, from the Arctic (Bergmann and Klages, 2012) to the Antarctic (Eriksson et al., 2013), and similar oceanic processes form high-concentration areas where debris gathers in the Atlantic Ocean and elsewhere.

You can help keep trash from becoming marine debris by (of course) reducing, reusing, and recycling; by downloading the NOAA Marine Debris Tracker app for your smartphone; and by learning more at http://marinedebris.noaa.gov.

Carey Morishige, Pacific Islands regional coordinator for the NOAA Marine Debris Program, also contributed to this post.

Literature Cited

Bergmann, M. and M. Klages. 2012. Increase of litter at the Arctic deep-sea observatory HAUSGARTEN. Marine Pollution Bulletin, 64: 2734-2741.

Donohue, M.J., R.C. Boland, C.M. Sramek, and G.A Antonelis. 2001. Derelict fishing gear in the Northwestern Hawaiian Islands: diving surveys and debris removal in 1999 confirm threat to coral reef ecosystems. Marine Pollution Bulletin, 42 (12): 1301-1312.

Eriksson, C., H. Burton, S. Fitch, M. Schulz, and J. van den Hoff. 2013. Daily accumulation rates of marine debris on sub-Antarctic island beaches. Marine Pollution Bulletin, 66: 199-208.

Howell, E., S. Bograd, C. Morishige, M. Seki, and J. Polovina. 2012. On North Pacific circulation and associated marine debris concentration. Marine Pollution Bulletin, 65: 16-22.

Morishige, C., M. Donohue, E. Flint, C. Swenson, and C. Woolaway. 2007. Factors affecting marine debris deposition at French Frigate Shoals, Northwestern Hawaiian Islands Marine National Monument, 1990-2002. Marine Pollution Bulletin, 54: 1162-1169.

Pichel, W.G., J.H. Churnside, T.S. Veenstra, D.G. Foley, K.S. Friedman, R.E. Brainard, J.B. Nicoll, Q. Zheng and P. Clement-Colon. 2007. Marine debris collects within the North Pacific Subtropical Convergence Zone [PDF]. Marine Pollution Bulletin, 54: 1207-1211.

Young L. C., C. Vanderlip, D. C. Duffy, V. Afanasyev, and S. A. Shaffer. 2009. Bringing home the trash: do colony-based differences in foraging distribution lead to increased plastic ingestion in Laysan albatrosses? PLoS ONE 4 (10).

Japan Confirms Dock on Washington Coast Is Tsunami Marine Debris

January 3, 2013 — A worker uses a 30% bleach spray to decontaminate and reduce the spread of possible marine invasive species on the Japanese dock which made landfall on Washington’s Olympic Peninsula in December 2012. (Washington Department of Fish and Wildlife/Allen Pleus)

The Japanese Consulate has confirmed that a 65-foot, concrete-and-foam dock that washed ashore in Washington’s Olympic National Park in late December 2012 is in fact one of three* docks from the fishing port of Misawa, Japan. These docks were swept out to sea during the earthquake and tsunami off of Japan in March 2011, and this is the second dock to be located. The first dock appeared on Agate Beach near Newport, Ore., in June 2012.

Using our trajectory forecast model, NOAA’s Office of Response and Restoration helped predict the approximate location of the dock after an initial sighting reported it to be floating somewhere off of Washington’s Olympic Peninsula. When the dock finally came aground, it ended up both inside the bounds of NOAA’s Olympic Coast National Marine Sanctuary and a designated wilderness portion of Olympic National Park.

In order to minimize damage to the coastline and marine habitat, federal agencies are moving forward with plans to remove the dock. In addition to being located within a designated wilderness portion of Olympic National Park, the dock is also within NOAA’s Olympic Coast National Marine Sanctuary and adjacent to the Washington Islands National Wildlife Refuge Complex. (National Park Service)

According to the Washington State Department of Ecology, representatives from Olympic National Park, Washington State Department of Fish and Wildlife, and Washington Sea Grant Program have ventured out to the dock by land several times to examine, take samples, and clean the large structure.

Initial results from laboratory testing have identified 30-50 plant and animal species on the dock that are native to Japan but not the United States, including species of algae, seaweed, mussels, and barnacles.

In addition to scraping more than 400 pounds of organic material from the dock, the team washed its heavy side bumpers and the entire exterior structure with a diluted bleach solution to further decontaminate it, a method approved by the National Park Service and Olympic Coast National Marine Sanctuary.

Government representatives are examining possible options for removing the 185-ton dock from this remote and ecologically diverse coastal area.

Look for more information and updates on Japan tsunami marine debris at http://marinedebris.noaa.gov/tsunamidebris/.

*[UPDATE 4/5/2013: This story originally stated that four docks were missing from Misawa, Japan and that "the first dock was recovered shortly afterward on a nearby Japanese island." We now know only three docks were swept from Misawa in the 2011 tsunami and none of them were found on a Japanese island.]

Small Japanese Boat Found near Vancouver Island, Canada, Even as Summer Currents Hold Marine Debris at Bay for now

The small boat which washed up on remote Spring Island, British Columbia, Canada, was positively identified as a vessel lost during the 2011 Japan tsunami. Credit: Kevin Head.

On remote Spring Island, northwest of Vancouver Island, Canada, a small boat inscribed with Japanese characters washed up with the tide this summer. A Canadian provincial official has confirmed this boat was lost during the 2011 Japan tsunami. Emergency Management British Columbia matched the serial number on the boat’s hull with one on the Japanese consulate’s list of vessels lost due to the tsunami. Eric Gorbman, who owns a nearby resort, and Kevin Head found and reported the boat on August 9, 2012.

A Summer Decrease in Debris

While this brings the total number of confirmed tsunami debris sightings to 11, summer weather patterns have created a lull in debris turning up on nearby Washington’s coast. This has the state Department of Ecology taking back some of the additional trash receptacles they provided near public access points earlier this summer. Recent decreases in reported marine debris in these areas, along with reports of someone using them to dump household waste, led to the removal.

“We want to ensure we are stretching our dollars as far as we can,” said Peter Lyon, a Washington Department of Ecology regional manager. “In June, when the boxes were placed along beaches, a southwest wind pattern directed more debris ashore in those areas than we are seeing now. When weather patterns shift again in the fall, we are likely to see higher amounts of debris again. So we want to conserve our resources in case that happens.”

The Washington Department of Ecology states that the trash bins can be easily and quickly redeployed within about 24 hours to accommodate possible increases in marine debris in the future. The funding to stock the bins and litter bags came from Department of Ecology’s litter account, setting aside $100,000 to deal with marine debris. These supplies help support community and volunteer efforts to collect and dispose of debris on Washington beaches.

Where Is the Debris Now?

NOAA’s Office of Response and Restoration has oceanographers Glen Watabayashi and Amy MacFadyen using our GNOME model to give us an understanding of where debris from the tsunami may be located today. GNOME is a software modeling tool used to predict the possible route pollutants might follow in a body of water, and we use it most frequently during an oil spill.

Our oceanographers are incorporating into this model how the winds and ocean currents since the tsunami may have moved items through the Pacific Ocean. However, rather than forecasting when debris will reach U.S. shores in the future, this model uses data from past winds and currents to show possible patterns of where debris may be concentrated right now.

“For me the story is not what’s been found but what hasn’t been found,” said NOAA oceanographer Glen Watabayashi. “With all the summer vessel traffic along the West Coast and out in the North Pacific, there have been no reports of any large concentrations of debris.”

Learn more at http://marinedebris.noaa.gov/tsunamidebris/.

NOAA Hauls 50 Metric Tons of Debris out of Hawaiian Waters

Scientists load onto a small boat marine debris collected at Midway Atoll in Papahānaumokuākea Marine National Monument. (NOAA)

With their eyes on the ocean, a team of 17 NOAA scientists recently removed nearly 50 metric tons of marine debris—mostly abandoned fishing nets and plastics—from the turquoise waters of Papahānaumokuākea Marine National Monument in the Northwestern Hawaiian Islands.

Part of an annual effort to restore the area’s coral ecosystems, this latest sweep of marine debris also scanned for items which might have been carried there from the 2011 Japan tsunami. However, nothing could be linked directly to the tragedy.

“While we did not find debris with an obvious connection to last year’s tsunami, this mission was a great opportunity to leverage activities that had already been planned and see what we might find,” said Carey Morishige, Pacific Islands regional coordinator for the NOAA Marine Debris Program, part of the Office of Response and Restoration. “It’s also an important reminder that marine debris is an everyday problem, especially here in the Pacific.”

NOAA divers cut a Hawaiian green sea turtle free from a derelict fishing net during a recent mission to collect marine debris in the Northwestern Hawaiian Islands. (NOAA)

Through NOAA’s Damage Assessment, Restoration, and Remediation Program, the Office of Response and Restoration is helping restore coral reefs here after the M/V Casitas grounded on Pearl and Hermes Atoll in the Northwestern Hawaiian Islands in July 2005. Part of the funding for the marine debris removal survey comes from the legal settlement for the Casitas ship grounding, as well as from the NOAA Marine Debris Program and Papahānaumokuākea Marine National Monument.

This recurring issue of marine debris threatens Hawaiian monk seals, sea turtles and other marine life in the coral reef ecosystems of the Northwestern Hawaiian Islands.  The scientists on this mission loaded the massive amounts of collected debris on to the 224-ft. NOAA Ship Oscar Elton Sette.

NOAA collected nearly 50 metric tons of marine debris, shown here with researchers sitting on top of the piles of nets aboard the ship Oscar Elton Sette during a July 2012 survey in the Northwestern Hawaiian Islands. (NOAA)

“What surprises us is that after many years of marine debris removal in Papahānaumokuākea and more than 700 metric tons of debris later, we are still collecting a significant amount of derelict fishing gear from the shallow coral reefs and shorelines,” said Kyle Koyanagi, marine debris operations manager at NOAA Fisheries’ Pacific Islands Fisheries Science Center and chief scientist for the mission. “The ship was at maximum capacity and we did not have any space for more debris.”

This year, marine debris was collected from waters and shorelines around the islands and atolls of the Northwestern Hawaiian Islands: Kure Atoll, Midway Atoll, Pearl and Hermes Atoll, Lisianski Island and Laysan Island.

Marine debris removed during this project will be used to create electricity through Hawaii’s Nets to Energy Program, a public-private partnership. Since 2002, it has collected and converted more than 730 metric tons of abandoned fishing gear into electricity—enough to power nearly 350 Hawaii homes for a year.

How Much Would it Cost to Clean up the Pacific Garbage Patches?

This is a post by Carey Morishige, Pacific Islands Regional Coordinator for the NOAA Marine Debris Program.

Over the last several years, the infamous “Great Pacific Garbage Patch” has gained popularity. Whether described as an island of trash or a soup of plastic, it has haunted the dreams of ocean conservationists. As I described in my last post, there are a lot of misconceptions about the so-called garbage patch, among them the size and amount of marine debris entrained in this area.

To understand the many unknowns about the “garbage patch,” you must first understand what the area really is. In a nutshell, it is a large area of marine debris concentration caused by the clockwise movement of the surface of the ocean. Sailors and fishermen have known of this area for decades—to them it is the North Pacific Subtropical High, a high pressure zone typically avoided by sailors.

One of the common questions we receive is: Why can’t we go out and clean this area up? Sounds easy and simple—if only it was! There are many factors that must be taken into account, such as the fact that these areas of concentrated marine debris move and change throughout the year and many of these areas also have abundant sea life, much of which is microscopic.

Let’s crunch some quick and dirty numbers on the cost of a cleanup:

Suppose we were to attempt to clean up less than 1% of the North Pacific Ocean (a 3-degree swath between 30° and 35°N and 150° to 180°W), which would be approximately 1,000,000 km². Assume we hired a boat with an 18 ft (5.5 m) beam and surveyed the area within 100 m off of each side of the ship.  If the ship traveled at 11 knots (20 km/hour), and surveyed during daylight hours (approximately 10 hours a day), it would take 67 ships one year to cover that area! At a cost of $5,000-20,000/day, it would cost between $122M and $489M for the year.  That’s a lot of money—and that’s only for boat time. It doesn’t include equipment or labor costs (keep in mind that not all debris items can be scooped up with a net).

Derelict fishing nets are frequently encountered marine debris items and cannot easily be scooped up with net. Credit: NOAA Fisheries Observer Program

The ultimate solution to the global problem of marine debris is not in clean up and removal (we can do that every day for the rest of our lives). The solution lies in prevention—stopping marine debris at the source; preventing trash from getting into our oceans and waterways in the first place!

For more information on the garbage patch and ways that you can help prevent marine debris, check out the NOAA Marine Debris Program website.

This originally was posted on the NOAA Marine Debris Blog.