5 ocean garbage patches you've never heard of
The Great Pacific Garbage Patch is the famous one. It's also one of five — each in its own ocean gyre, each accumulating plastic.
Why there are five
The world's ocean has five major subtropical gyres — large, slow, circular current systems driven by global wind patterns and the Coriolis effect. Each gyre rotates around a relatively still center where floating debris naturally concentrates. All five are accumulating plastic. Only the North Pacific gyre's patch — the famous Great Pacific Garbage Patch — gets sustained media coverage. The other four are documented but less-discussed.
1. North Pacific Subtropical Gyre — Great Pacific Garbage Patch
The largest, most-studied, and most-famous. Estimated 1.6 million km², ~80,000 tons of plastic, ~1.8 trillion pieces. Located between Hawaii and California. Read the full deep dive.
2. North Atlantic Subtropical Gyre — North Atlantic Garbage Patch
Second-most studied. Located in the central North Atlantic, west of the Azores. Discovered through long-term sampling by the Sea Education Association from 1986 onward. The North Atlantic patch is smaller and less concentrated than the Pacific equivalent — partly because the surrounding land masses (and economies) generate less plastic input than the Pacific Rim.
Estimated mass: tens of thousands of tons across millions of square kilometers; concentration densities are similar to the GPGP but the total is smaller.
3. South Pacific Subtropical Gyre
The least-sampled of the five major patches. Located in the South Pacific between South America and Australia. The 5 Gyres Institute conducted sampling expeditions through this gyre in the 2010s and confirmed substantial plastic accumulation, though at lower density than the Pacific patches in the Northern Hemisphere.
Notable feature: the South Pacific gyre is one of the most remote ocean regions on earth. The fact that it's accumulating plastic is itself a marker of how globally distributed plastic pollution has become.
4. South Atlantic Subtropical Gyre
Located in the South Atlantic, between Brazil and southern Africa. Less-studied than the North Atlantic equivalent, but documented to contain meaningful plastic accumulation. Recent sampling expeditions by various ocean conservation groups have confirmed presence at concentrations comparable to or below the South Pacific gyre.
5. Indian Ocean Subtropical Gyre
The Indian Ocean gyre rotates in the southern Indian Ocean, off the east coast of Africa. Concentrations are growing rapidly — partly because the surrounding region has some of the world's fastest-growing populations and the largest river-borne plastic input pathways (the major rivers of South Asia and East Africa).
Beyond the five — accumulation zones not in gyres
Plastic also accumulates in other less-studied zones:
- Polar regions: the Arctic is increasingly accumulating plastic through trans-polar currents and shipping. Sampling in the Beaufort Sea has shown microplastic concentrations comparable to mid-ocean gyres.
- The Mediterranean: the world's most plastic-polluted enclosed sea by some metrics. Limited circulation means plastic doesn't disperse — it concentrates in coastal accumulation zones.
- Deep sea trenches: the Mariana Trench and other ultra-deep zones contain plastic — including, famously, a plastic bag found at 10,898 m depth in 2018. More on deep-sea plastic.
What this means for ocean cleanup
Cleaning one gyre is hard. Cleaning five is harder. Cleaning the polar regions, deep sea, and enclosed seas is essentially impossible at current technology. The strategic implication: source reduction is the only scalable solution. The plastic that's already in the ocean is essentially permanent on human timescales; the only variable we control is how much more we add.