The Great Pacific Garbage Patch — And the Truth About the Trash-Island Myth

A gyre is a large system of rotating ocean currents — a slow, ocean-wide whirlpool. There are five great subtropical gyres: the North and South Pacific, the North and South Atlantic, and the Indian Ocean. They are driven by steady winds and bent into a loop by the Earth's rotation (the Coriolis effect), so they turn clockwise in the Northern Hemisphere and counter-clockwise in the Southern. Anything floating that drifts into a gyre tends to be carried toward its calm centre and trapped there — which is exactly why our floating plastic ends up where it does (NOAA Marine Debris Program, 2024).

The most-cited estimate comes from a 2018 study led by Laurent Lebreton of The Ocean Cleanup, published in Scientific Reports. Using ship trawls and aircraft surveys, the team estimated the patch covers about 1.6 million square kilometres — roughly three times the size of France, or twice the size of Texas — and contains an estimated 1.8 trillion pieces of plastic weighing about 79,000 tonnes (Lebreton et al., 2018). It has no hard edge, though: it is a gradient of plastic concentration that simply fades out, so any single 'size' is a definition as much as a measurement.

No — and this is the single most important thing to understand about it. You cannot see the Great Pacific Garbage Patch from space, you cannot stand on it, and you could sail a boat straight through large parts of it and barely notice anything in the water. NOAA describes it as more like pepper flakes stirred through a soup than a floating landfill. Most of the pieces are microplastics smaller than half a centimetre, spread thinly through an enormous volume of water from the surface down into the deep. The 'island' image is a myth — a vivid but misleading one (NOAA Marine Debris Program).

By count, the overwhelming majority of pieces are microplastics — tiny fragments worn down from larger items. But by weight the picture flips: the 2018 survey estimated that nearly half the total mass is abandoned, lost or discarded fishing gear, especially nets, often called 'ghost nets' because they keep trapping marine life long after they are lost (Lebreton et al., 2018). So the patch is, at the same time, mostly tiny fragments and mostly fishing gear — depending on whether you count pieces or weight.

Yes. Every one of the five subtropical gyres collects plastic in its centre. The North Pacific patch is by far the most studied and the largest, but accumulation zones have been confirmed in the North Atlantic (Law et al., Science, 2010), the South Pacific (Eriksen et al., 2013) and, in global models, the South Atlantic and Indian Ocean as well. Across all five gyres, one widely cited study estimated at least 5.25 trillion pieces of plastic — about 269,000 tonnes — floating on the world ocean (Eriksen et al., PLOS ONE, 2014).

It is far harder than it sounds, precisely because it is so diffuse. The particles are tiny, scattered through a huge area and depth of water, and constantly moving — so scooping them out is slow, expensive and risks catching sea life along with the plastic. Most researchers argue that the higher-leverage fix is prevention: stopping plastic from reaching the ocean in the first place, especially from rivers and from fishing gear, since one bottle intercepted upstream prevents the thousands of microplastic fragments it would eventually break into. Cleanup and prevention both have roles, but prevention is where the maths favours us.

The patch markers sit at the real convergence centre of each gyre, and every figure attached to them is sourced and dated. But the gyre loops themselves are an authored schematic — a clean drawing placed over each gyre's true position to show how it turns and what it traps, not a measured streamline of the actual currents. The live, measured companions on the Ocean canvas are the surface-current particle layer and the Argo float profiles.