NOAA's Response and Restoration Blog

An inside look at the science of cleaning up and fixing the mess of marine pollution


Leave a comment

Visualizing How Ocean Currents Help Create the Garbage Patches

Plastic water bottle floating in the ocean.

The “garbage patches” are not giant, floating islands of trash, but rather, ocean gathering places for what are mainly tiny bits of plastic dispersed throughout the water column, with some larger items as well. (NOAA)

The data whizzes at NASA recently decided to turn their attention from the sky to the ocean as they attempted to model how ocean currents help drive the formation of the “garbage patches.” From NASA:

“We start with data from floating, scientific buoys that NOAA has been distributing in the oceans for the last 35 years represented here as white dots … If we let all of the buoys go at the same time, we can observe buoy migration patterns … The buoys migrate to 5 known gyres also called ocean garbage patches.

We can also see this in a computational model of ocean currents called ECCO-2. We release particles evenly around the world and let the modeled currents carry the particles. The particles from the model also migrate to the garbage patches.”

Check out their data visualization here:

As you might gather from the visualization, the gyres, where “garbage patches” are located, represent massive, dynamic areas of the ocean that are constantly moving and changing—and as a result, are also bringing trash and other marine debris with them. Rather than giant, floating islands of trash that you can see from satellites (you can’t), “garbage patches” are ocean gathering places for what are mainly tiny bits of plastic dispersed throughout the water column.

Still fuzzy on what the garbage patches are and are not? Check out this video from the NOAA Marine Debris Program:

And tune in to this National Ocean Service podcast to learn what we know and don’t know about the garbage patches and what we can do about this ocean-sized problem:

You can also read about our own efforts to model where marine debris travels across the ocean.


2 Comments

Taking a Closer Look at Marine Debris in Your Backyard

Here's hoping your backyard doesn't look like this: debris scattered on the ocean floor near the Pacific Islands. (NOAA)

Here’s hoping your backyard doesn’t look like this: debris scattered on the ocean floor near the Pacific Islands. (NOAA)

Check out NOAA’s Marine Debris Blog for their ongoing series, Marine Debris in Your Backyard, which examines the unique challenges of marine debris and its impacts on various parts of the United States.

Join them as they “journey across the nation, looking at the nine different regions the NOAA Marine Debris Program spans and the most common types of debris found in them, and how it may have ended up there.”

So far, they have visited the following places:

  • Alaska, where remote beaches, rough seas, and limited fair weather mean volunteers have only a few months each year to remove anywhere from one to 25 tons of debris per mile of shoreline.
  • Great Lakes, where 21 percent of the world’s surface fresh water resides, discarded fishing lines often entangle wildlife, and rumors of a plastic-filled “garbage patch” are beginning to appear.
  • Pacific Islands, where Hawaii, Guam, American Samoa, the Commonwealth of the Northern Mariana Islands, and a whole lot of open ocean make up the largest region NOAA supports, but where there is so little space for landfills that NOAA helped establish a public-private partnership in Hawaii to turn abandoned fishing gear into a local electricity source.
  • California, where its 1,100 miles of shoreline vary from coastal mountains in the north to well-populated, sandy beaches in the south, and where the nation’s first “Trash Policy” will attempt to control the flow of garbage in California’s waterways.

Stay tuned as they continue working their way around the shores of the United States, and ask yourself, what does marine debris look like where you live? How do you help keep it out of the ocean?

And remember, even if you live hundreds of miles from a beach, a piece of litter such as a cigarette butt (which actually contains plastic) or a plastic bag can still make its way through storm drains and rivers to the ocean. This makes marine debris, no matter where you live, truly everyone’s problem.


5 Comments

Is There a Garbage Patch in the Great Lakes?

This is a post by Sarah Opfer, NOAA Marine Debris Program Great Lakes Regional Coordinator.

Plastic debris in the form of fragments, bottle caps, food packaging, and smoking products are commonly found on Great Lake beaches. Here, marine debris has washed up at Maumee Bay State Park on the shores of Lake Erie. (NOAA Marine Debris Program)

Plastic debris in the form of fragments, bottle caps, food packaging, and smoking products are commonly found on Great Lake beaches. Here, marine debris has washed up at Maumee Bay State Park on the shores of Lake Erie. (NOAA Marine Debris Program)

The “Great Pacific Garbage Patch“—a purported island of trash twice the size of Texas floating in the Pacific Ocean—receives a lot of media attention. Recent reports suggest that a similar garbage patch may be developing in the Great Lakes as well.

However, based on research we know that the name “garbage patch” is misleading and that there is no island of trash forming in the middle of the ocean. We also know that there is no blanket of marine trash that is visible using current satellite or aerial photography.

Plastic debris is found in Great Lake waters as well. This debris was pulled from a Lake Erie marina during a cleanup. (NOAA Marine Debris Program)

Plastic debris is found in Great Lake waters as well. This debris was pulled from a Lake Erie marina during a cleanup. (NOAA Marine Debris Program)

Yet, there are places in the ocean where currents bring together lots and lots of floatable materials, such as plastics and other trash. While the types of litter gathering in these areas can vary greatly, from derelict fishing nets to balloons, the kind that is capturing the most attention right now are microplastics. These are small bits of plastic often not immediately evident to the naked eye.

While we know about the so-called “garbage patches” in the Pacific Ocean, could there be a similar phenomenon in other parts of the world, including the Great Lakes? Recent research on the distribution of plastics in the Great Lakes has people now asking that very question.

The Great Lakes are no mere group of puddles. They contain nearly 20% of the world’s surface freshwater and have a coastline longer than the East Coast of the United States. Within the Great Lakes system, water flows from Lake Superior and Lake Michigan, the lakes furthest west and highest in elevation, east into Lake Huron. From there, it travels through Lake St. Clair and the Detroit River into Lake Erie. Then, some 6 million cubic feet of water pass over Niagara Falls each minute and into Lake Ontario before flowing through the St. Lawrence River and into the Atlantic Ocean.

Average summer water circulation patterns in the Great Lakes. Beletsky et al. 1999 (NOAA Great Lakes Environmental Research Laboratory)

Average summer water circulation patterns in the Great Lakes. Beletsky et al. 1999 (NOAA Great Lakes Environmental Research Laboratory)

This water flow influences circulation patterns within and between each of the lakes. Currents within the Great Lakes also are powered by wind, waves, energy from the sun, water density differences, the shape of the lakebed, and the shoreline. These circulation currents have the tendency to create aggregations of garbage and debris in certain areas, just like in the oceans. But, just as in the Pacific Ocean, this doesn’t mean the Great Lakes have floating trash islands either.

In an effort to better identify and understand how plastic debris is spread throughout the Great Lakes, researchers at the University of Waterloo in Canada have partnered with COM DEV on an exploratory research project. COM DEV is a designer and manufacturer of space and remote sensing technology. Researchers are working with this industry partner to develop and test the ability of different remote sensors to detect plastics in the Great Lakes.

If they find the task is feasible and the trial runs prove to be effective, this work could be applied beyond the Great Lakes and across the United States. The NOAA Marine Debris Program, part of the Office of Response and Restoration, is engaged with and following the project. We plan to participate in the next steps of this promising effort. You can learn more about the project and a related workshop on plastic pollution in the Great Lakes.

Sarah Opfer

Sarah Opfer

Sarah Opfer received her bachelor’s and master’s degrees in biology from Bowling Green State University and was a Knauss Sea Grant fellow with NOAA in 2009. She is based in Ohio and enjoys having Lake Erie in her back yard! While away from work she enjoys cooking, reading, kayaking, dreaming of places she wants to travel to, and spending time with her family.


10 Comments

Where Are the Pacific Garbage Patches Located?

Microplastics in sand.

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.

Map of ocean currents, features, and areas of marine debris accumulation (including

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:

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).