The “garbage patch,” as referred to in the media, is an area of marine debris concentration in the North Pacific Ocean. The name “garbage patch” has led many to believe that this area is a large and continuous patch of easily visible marine debris items such as bottles and other litter—akin to a literal blanket of trash that should be visible with satellite or aerial photographs. This is simply not true. While litter items can be found in this area, along with other debris such as derelict fishing nets, much of the debris mentioned in the media these days refers to small bits of floatable plastic debris. These plastic pieces are quite small and not immediately evident to the naked eye.

Where is the “garbage patch”?
It appears that the “garbage patch” referred to in the media is within the North Pacific Subtropical High, an area between Hawaii and California. Due to limited marine debris samples collected in the Pacific it is still difficult to predict its exact content, size, and location. However, marine debris has been quantified in higher concentrations in the calm center of this high-pressure zone compared to areas outside this zone. It should be noted that the North Pacific Subtropical High is not a stationary area, but one that moves and changes. This area is defined by the NOAA National Weather Service as "a semi-permanent, subtropical area of high pressure in the North Pacific Ocean. It is strongest in the Northern Hemispheric summer and is displaced towards the equator during the winter when the Aleutian Low becomes more dominant. Comparable systems are the Azores High and the Bermuda High."

Is the “garbage patch” the only area where marine debris concentrates?
NO. There are several features within our oceans that concentrate marine debris, including oceanic eddies and convergence zones. See below and our page on Marine Debris Movement for more information.

ONE EXAMPLE is the North Pacific Subtropical High or “garbage patch.”

ANOTHER EXAMPLE is an area known as the North Pacific Subtropical Convergence Zone (STCZ).

The STCZ is located along the southern edge of an area known as the North Pacific Transition Zone (click here for detailed information on the Transition Zone). NOAA has focused on the STCZ because it is an area of high productivity, pelagic species feeding and migration, and documented marine debris concentration – and one of the reasons for marine debris accumulation in Hawaii (see below) (Kubota, 1994; Pichel et al., 2007). This area does not have distinct boundaries and varies in location and intensity of convergence throughout the year. This zone moves seasonally between 30° and 42° N latitude (approximately 800 miles), extending farther south (28°N) during periods of El Niño (Donohue and Foley, 2007). It is less well defined and located more northerly during the summer months, when convergence tends to be weaker, and is sharper and located farther south during winter months, when convergence is stronger.
North Pacific Subtropical Convergence Zone as a mechanism for accumulation of marine debris in Hawaii:
The Hawaiian Archipelago, extending from the southernmost island of Hawaii 1,500 miles northwest to Kure Atoll, is among the longest and most remote island chains in the world. In Hawaii, marine debris continues to present a hazard to marine habitat, safe navigation, and wildlife, including the endangered Hawaiian monk seal (Monachus schauinslandi) and various species of sea turtles, seabirds, and whales. It is the location of this archipelago, between 18° and 28° N latitude, which makes it prone to the accumulation of marine debris. One of the reasons marine debris accumulates in these islands is the movement of debris within the North Pacific Subtropical Convergence Zone (STCZ). The STCZ concentrates debris and moves seasonally between 30° and 42° N latitude, dipping farther south (28°N) during periods of El Niño. This accumulation due to the STCZ is evidenced by an increase in the quantity of floating marine debris deposited on beaches during El Niño periods (Morishige et al., 2007). Additionally, a correlation has been noted between increased entanglements of endangered Hawaiian monk seals in marine debris and periods of El Niño (Donohue and Foley, 2007).

What is the difference between the "gyre" and the “garbage patch”? Or are they the same thing?
A gyre is a large-scale circular feature made up of ocean currents that spiral around a central point, clockwise in the Northern Hemisphere and counterclockwise in the Southern Hemisphere. Worldwide, there are five major subtropical oceanic gyres: the North and South Pacific Subtropical Gyres, the North and South Atlantic Subtropical Gyres, and the Indian Ocean Subtropical Gyre. The North Pacific Subtropical Gyre is the one most notable because of its tendency to collect debris. It is made up of four large, clockwise-rotating currents – North Pacific, California, North Equatorial, and Kuroshio. It is very difficult to measure the exact size of a gyre because it is a fluid system, but the North Pacific Subtropical Gyre is roughly estimated to be approximately 7 to 9 million square miles—not a small area! This, of course, is a ballpark estimate. This is equivalent to approximately three times the area of the continental United States (3 million square miles).

While a gyre may aggregate debris on a very large scale, debris patches, as seen by those sailing the North Pacific, are actually the result of various smaller-scale oceanographic features such as oceanic eddies and frontal meanders (think of meanders as the deviation from a straight line. As energy (wind/currents) hit the front there are undulations and "curvature" which are described as frontal meanders (movements to the north and south along the front)).

How big is the “garbage patch”?
There has been extensive media coverage about the “garbage patch” over the past couple years; however, its reported size and mass have differed from article to article. Due to the limited sample size, as well as a tendency for observing ships to explore only areas thought to concentrate debris, there is really no accurate estimate on the size or mass of the “garbage patch” or any other concentrations of marine debris in the open ocean. Additionally, many oceanographic features do not have distinct boundaries or a permanent extent, and thus the amount of marine debris (both number and weight) in this zone would be very difficult to measure accurately. The “patchiness” of debris in this expansive area would make a statistically sound survey quite labor-intensive and likely expensive.

Regardless of the exact size, mass, and location of the “garbage patch,” manmade debris does not belong in our oceans and waterways.
Can you see the “garbage patch” with satellite photos?
NO. Relative to the expanse of the North Pacific Ocean, sightings of large concentrations of debris, especially of large debris items are not very common. A majority of the debris observed in the “garbage patch” is small plastic pieces. Small debris pieces are difficult to see due to their size, and many of these pieces may be suspended below the surface of the water, which would make them even harder to see, even with the human eye. For these reasons, the debris, or “patch” of debris is not visible with existing satellite technology.