Evidence that the Great Pacific Garbage Patch is rapidly accumulating plastic.

Area of Science:

• Marine pollution
• Oceanography
• Environmental science

Background:

• Ocean plastic pollution is a persistent global issue, with accumulation zones forming in remote oceanic regions.
• The Great Pacific Garbage Patch (GPGP) is a major accumulation zone located in subtropical waters between California and Hawaii.

Purpose of the Study:

• To characterize and quantify the extent of plastic pollution within the Great Pacific Garbage Patch.
• To compare current plastic mass estimates with previous reports and identify contributing factors to discrepancies.

Main Methods:

• Utilized data from multi-vessel and aircraft surveys to calibrate a predictive model.
• Employed robust methods for quantifying larger plastic debris to improve accuracy.
• Analyzed the characteristics of collected plastic debris to understand persistence and accumulation.

Main Results:

• The GPGP contains an estimated 79 thousand tonnes of plastic across 1.6 million km², significantly higher than prior estimates.
• Over 75% of the plastic mass consists of debris larger than 5 cm, with fishing nets accounting for at least 46%.
• Microplastics constitute 8% of the total mass but 94% of the estimated 1.8 trillion pieces of plastic.

Conclusions:

• The GPGP's plastic mass is substantially underestimated by previous studies, largely due to methodology for larger debris.
• Fishing gear represents a significant component of the GPGP's plastic mass.
• Ocean plastic pollution in the GPGP is increasing exponentially, at a faster rate than in surrounding waters.