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.

	L	S	S:L	P:L	P:S
Arctic	1.5 × 10−1	1.7 × 10−2	1.1 × 10−1	3.4 × 102	3.1 × 103
Mediterranean	7.6 × 101	3.1 × 10−1	4.1 × 10−3	5.5 × 100	1.3 × 103
North Atlantic	8.8 × 100	6.7 × 10−2	7.6 × 10−3	6.9 × 100	9.1 × 102
North Pacific	9.6 × 100	4.7 × 10−2	4.9 × 10−3	6.6 × 100	1.3 × 103
Indian	7.6 × 100	3.2 × 10−2	4.2 × 10−3	4.0 × 100	9.5 × 102
South Atlantic	2.4 × 100	1.8 × 10−2	7.4 × 10−3	2.6 × 101	3.5 × 103
South Pacific	9.4 × 10−1	7.1 × 10−3	7.5 × 10−3	2.7 × 101	3.6 × 103
Global	6.2 × 100	3.4 × 10−2	5.5 × 10−3	7.8 × 100	1.4 × 103