Table 2.
Mean observed mass and numerical concentrations within the 1.6 million km2 GPGP for different size and type of ocean plastics.
| Size class | Type | Mean mass concentration (kg km−2) | Mean numerical concentration (# km−2) |
|---|---|---|---|
| Microplastic (0.05–0.5 cm) | H | 2.33 | 643,930 |
| N | 0.041 | 19,873 | |
| P | 0.13 | 14,362 | |
| F | 0.001 | 216 | |
| Mesoplastic (0.5–5 cm) | H | 3.68 | 20,993 |
| N | 0.23 | 803 | |
| P | 0.0003 | 3.6 | |
| F | 0.003 | 12 | |
| Macroplastic (5–50 cm) | H | 15.53 | 640 |
| N | 1.27 | 49 | |
| F | 0.021 | 0.7 | |
| Megaplastic (>50 cm) | H | 3.52 | 0.3 |
| N | 42.82 | 3.3 | |
| All | All | 69.58 | 700,886 |
Plastic type H include pieces of hard plastic, plastic sheet and film, type N encompasses plastic lines, ropes and fishing nets, type P are pre-production plastic pellets, and type F are pieces made of foamed material.