Table 2 Ratios of surface plastic load to local pollution sources in the Arctic and other ocean basins.

Land-based pollution sources (L) were estimated from a population in a 50-km coastal strip, and sea-based pollution sources (S) were estimated from at-sea vessel density. Surface plastic loads (P) were obtained from the present work and previous reports (2, 7). L and S are expressed in persons or vessels per square kilometer of ice-free waters, respectively. S:L ratios are expressed in vessels per person, P:L ratios are expressed in grams of plastic per person, and P:S ratios are expressed in grams of plastic per vessel. Global estimates do not include the Southern Ocean because of the lack of plastic pollution data for that basin.

LSS:LP:LP:S
Arctic1.5 × 10−11.7 × 10−21.1 × 10−13.4 × 1023.1 × 103
Mediterranean7.6 × 1013.1 × 10−14.1 × 10−35.5 × 1001.3 × 103
North Atlantic8.8 × 1006.7 × 10−27.6 × 10−36.9 × 1009.1 × 102
North Pacific9.6 × 1004.7 × 10−24.9 × 10−36.6 × 1001.3 × 103
Indian7.6 × 1003.2 × 10−24.2 × 10−34.0 × 1009.5 × 102
South Atlantic2.4 × 1001.8 × 10−27.4 × 10−32.6 × 1013.5 × 103
South Pacific9.4 × 10−17.1 × 10−37.5 × 10−32.7 × 1013.6 × 103
Global6.2 × 1003.4 × 10−25.5 × 10−37.8 × 1001.4 × 103