The Great Pacific Garbage Patch: Overview, Impacts, and Solutions

The Great Pacific Garbage Patch (GPGP) is one of a number of stretches of ocean littered with plastic trash. While larger items like fishing nets or plastic shopping bags are the most visible components of ocean debris, up to 51 trillion microplastic particles float in our oceans. Plastic pollution contaminates every ocean from surface to seafloor and from tropical waters to Arctic ice. It suffocates sea creatures large and small and enters all marine ecosystems and food webs, including the seafood that humans consume. If you are what you eat, then you are also what you throw away.

Every ocean has at least one garbage patch. Garbage patches also accumulate in coastal ecosystems where rivers meet the sea or where tidal flows trap buoyant plastic—important habitats for many marine species. The Great Pacific Garbage Patch is only the best known and largest deposit of ocean trash, and its cleanup has become a focal point of efforts to address the global problem of ocean plastic pollution.

How the Garbage Patch Formed

Ocean plastic debris was first identified in 1972 in the Sargasso Sea, part of the western Atlantic. What is now known as the Great Pacific Garbage Patch was discovered in 1997 and came to prominence in a series of articles by Los Angeles Times writer Ken Weiss in 2006.

Debris patches have formed in all oceanic gyres, huge spirals of seawater formed by colliding currents. The upper part of the North Pacific Subtropical Gyre, a few hundred miles north of Hawaii, is where warm water from the South Pacific crashes into cooler water from the north. Known as the North Pacific Subtropical Convergence Zone, this is where the GPGP has formed.

By mass, nearly half of the plastic debris in the Great Pacific Garbage Patch is from fishing nets—known as ghost nets—the result of increasingly intensive fishing in the Asia Pacific region. But microplastics make up 94% of the estimated 1.8 trillion plastic pieces of the GPGP. Those microplastics come from synthetic fishing nets, as well as a wide variety of land-based sources: plastic bags, bottles, and various other consumer products. A stunning 90% of all plastic items are used once and discarded. Only 9% of all plastic by mass gets recycled.

Eventually, an estimated 11% of all plastic waste ends up in aquatic ecosystems. Rivers are a significant source, as some 80% of ocean plastic comes from just 1,000 rivers worldwide, but so too are stormwater runoff, wind-blown litter from landfills or garbage bins, and sewage overflows. According to one study, about 8 million metric tons of plastic now enter the ocean during a typical year, mostly coming from people who live within 50 kilometers (30 miles) of a coastline, but also from even farther inland.

It can be a six- or seven-year journey before it arrives in the garbage patch. On the other hand, larger materials such as fishing nets and shipping containers often fall off ships directly into the ocean. One of the most famous of such debris spills came in 1992, when 28,000 rubber ducks fell overboard in the Pacific. Another is the soccer ball swept into the Pacific during the Fukushima earthquake and tsunami which washed up on the shore of a remote Alaskan island.

Environmental Impacts, Big and Small

The environmental impact of plastic pollution in the GPGP depends on the size of the debris. While larger debris floats on or near the surface and affects larger marine life, smaller plastic particles floating make their way down the water column toward the seafloor, then make their way up the food chain from the smallest creatures to the largest, including us.

Surface Plastics

Megaplastics like fishing nets entangle oxygen-breathing marine life, such as dolphins, seals, sea turtles, and other animals, often drowning them. Sea turtles frequently swallow plastic bags, mistaking them for jellyfish, their main prey. The plastic fills their stomachs, causing them to die of starvation. Smaller surface items like plastic resin pellets (aka nurdles) are another common component of marine debris.

The tiny, toxic granules are shipped in bulk around the world, melted down at manufacturing sites, and remolded into commercial plastics. Floating on the sea surface, they wreak havoc with sea birds like the short-tailed albatross, which mistakes them for fish eggs that they harvest and feed to their young, who eventually die of starvation or ruptured organs.

Microplastics

The United Nations Environment Programme (UNEP) considers microplastics and the even smaller nanoplastics among the world's top environmental challenges. The main problems are their permanence and their toxicity. Fossil fuel-based plastic is primarily non-biodegradable, though sunlight does eventually "photodegrade" the bonds in plastic polymers, reducing them to smaller and smaller pieces.

This just makes matters worse: When plastics floating on or near the ocean surface are exposed to sunlight, they release methane and ethylene, two potent greenhouse gases that contribute to global warming. Photodegradation also releases colorants and chemicals like bisphenol-A, which studies have linked to various environmental and health problems. One-quarter of all carnivorous fish in China's Xiangxi River were found to have microplastics in their digestive tracts. Ingesting microplastics affects animal growth rates and constitutes a health risk to humans as well.

What Is Being Done?

The effort to abate plastic pollution in marine environments is three-pronged: removing pollutants already in the environment; recycling or repurposing plastics before they reach waterways; and limiting the production of plastic in the first place (as well as striving to curb demand).

Cleanup Efforts

Stirred into action by increasing media focus on marine plastic pollution, cleanup efforts such as those that are part of World Environment Day act to remove pollution from the rivers and beaches before the trash heads out to sea. The Clean Seas campaign, led by the United Nations Environment Programme, is another global effort to remove and reduce marine litter. Perhaps the most well-known effort is Ocean Cleanup, launched in 2018 by Boyan Slat, a Dutch inventor who came up with the idea as a teenager. Ocean Cleanup is also the creator of Interceptors, solar-powered boats that remove trash from rivers before it reaches the ocean.

Recycling

Stopping plastics from entering the waste stream in the first place is preferable to cleaning up the mess afterward. This involves reducing or eliminating the 90% of plastics that are used once and increasing the number of plastics that get recycled from its current rate of 9%. (Only 14% is collected to begin with.) Since 1991, nations, states, and municipalities have adopted policies to reduce or eliminate single-use plastic bags.

After introducing a fee on single-use plastic bags, for example, the United Kingdom witnessed a sharp decline in offshore debris. Making producers pay for plastic pollution can also increase recycling efforts. Norway's innovative program of taxing bottling companies if plastic bottle recycling rates drop below 95% has led to a world-leading 97% of Norway's bottles being recycled. (It's important to remember, though, that plastic only ever gets downcycled into a lesser version of itself, so it can never be reincarnated in the same form that it started.)

Carrots as well as sticks also increase recycling. Creating a larger market for recycled plastics—and a higher reward for recycling them—also prevents them from entering waterways. In Rome, people can purchase metro tickets with plastic bottles. Amsterdam's Plastic Whale organization can provide low-cost tours of the city's many canals because their passengers collect profitable plastic waste from the waterways.

Raising the value of recycled plastics also increases the percentage recycled, especially in developing countries. In India informal sector recyclers (small-scale, independent workers who scavenge scrap yards and other urban waste sites) are the reason for the country's relatively high plastic recycling rate of 48%.

Make recycling profitable and its rates increase. This is easier said than done. As reported on Treehugger regarding California's recycling center closures, "Recycling doesn't work if the stuff has no value. Recycled PET is worthless now because natural gas is so cheap that virgin PET is cheaper than cleaning and processing recycled."

Limiting Production

While cleanup can mitigate plastic pollution and recycling can reduce the amount of plastic trash, neither of these efforts can keep pace with the rate of plastic production, which has boomed from roughly 1.5 million tons in 1950 to 348 million tons in 2017. As with the climate crisis, the source of the product is the source of the problem.

Indeed, the two crises are related, since like oil and gas, most non-biodegradable plastics are fossil-fuel based. As declining demand for fossil fuels and government policies to reduce carbon emissions cut into the fossil fuel industry's profits, oil companies have turned to plastics to make up for their lost revenues.

The production problem is one of price: Just as a drop in gas prices leads to larger vehicles and more emissions, low prices make plastic cheaper than the alternatives. For example, the lower cost of plastic nets compared to traditional ones made from natural fibers has led to their widespread adoption and increased abandonment at sea.

Similar to a carbon tax, a plastic tax can both increase recycling and reduce consumption. In 2021, Maine became the first state in the U.S. to require companies that use single-use packaging to pay for the cost of recycling. Those costs will be passed on to the consumers, of course, with the intended goal that the use of plastic declines. Legislation to promote reusables in place of single-use disposable packaging is important, too.