The Great Pacific Garbage Patch (GPGP) is frequently envisioned as a vast, floating dump brimming with bottles and bags, situated between California and Hawaii. Nonetheless, the truth is considerably more intricate. As per a 2018 study published in *Scientific Reports* by Laurent Lebreton and his team at The Ocean Cleanup, the GPGP encompasses roughly 79,000 metric tons of floating plastic scattered across about 1.6 million square kilometers of ocean. This translates to an average of about 50 kilograms of plastic per square kilometer, although the concentration fluctuates remarkably, with denser areas towards the center.
In contrast to the typical portrayal of plastic pollution, a sizable share of the GPGP comprises larger items. The 2018 assessment indicated that more than three-quarters of the patch’s weight consisted of objects exceeding 5 centimeters, with at least 46% of this weight made up of fishing nets. A subsequent 2022 study determined that 75 to 86 percent of large floating plastic in the North Pacific gyre could be traced back to fishing pursuits, with predominant sources identified as Japan, China, South Korea, the United States, and Taiwan, which are key fishing nations in the North Pacific.
This undermines the notion that ocean plastic pollution is chiefly a consumer issue, like plastic bags and straws, and underscores the considerable influence of fishing operations. Nevertheless, it’s crucial to acknowledge that this data refers to one specific gyre. While the North Pacific accumulation zone exhibits a predominance of fishing-related debris, global ocean plastic pollution is primarily derived from land-based activities, with river discharges accounting for 1.15 to 2.41 million metric tons annually, based on The Ocean Cleanup’s findings.
Moreover, while most of the recoverable mass is attributed to fishing gear, the Great Pacific Garbage Patch is predominantly comprised of microplastics when evaluating the number of pieces. The 2018 study approximated that microplastics constituted 8% of the mass yet accounted for 94% of the estimated 1.8 trillion plastic pieces.
The insights from these studies are vital for developing targeted solutions, such as gear marking and compulsory reporting of fishing gear losses, which may prove to be more effective than consumer-oriented initiatives like straw bans. However, these observations pertain specifically to the North Pacific. The makeup of other ocean gyres, which have been less comprehensively studied, might differ, possibly shifting the overall comprehension of ocean plastic pollution.
Future investigations comparing plastic compositions across varying ocean gyres would be essential to determine if the findings from the North Pacific can be applied globally. Until additional studies are undertaken, the existing evidence suggests that most of the weighed debris in the most examined patch of floating plastic is derived from fishing activities.