Table 3.1.

Estimates of the amounts of plastic debris floating at the ocean surface. Global estimates range from 0.09% to 12% of the 4.8–12.7 million metric tons of plastic waste estimated to enter the ocean in [24] Regarding debris size, most plastics collected in plankton nets are millimeters in size or smaller, although many studies do not report particle size distribution. Here, “nominal” refers to all plastic debris collected in plankton nets, the majority of which is likely to be microplastic (<5 mm in size).

ESTIMATED MASS	MEASUREMENT METHOD	DEBRIS SIZE	REGION(# MEASUREMENTS)	STUDY
1,100 tons	Plankton net(0.335 mm mesh)	Microplastic (nominal)	Western North Atlantic Ocean (6,136)	(Law et al., 2010) [600]
21,290 tons	Plankton net(0.335 mm mesh)	Microplastic (nominal)	Eastern North and South Pacific Ocean (2,529)	(Law et al., 2014) [607]
6,350–31,750 tons	Plankton nets(0.2 mm–1 mm mesh)	Microplastic (nominal)	Global (3,070)	(Cózar et al., 2014) [601]
66,140 tons	Plankton net(0.33 mm mesh)	0.33–200 mm	Global (680)	(Eriksen et al., 2014) [602]
202,800 tons	Visual survey transects	>200 mm	Global (891)	(Eriksen et al., 2014) [602]
93,000–236,000 tons	Plankton nets(0.15–3 mm mesh)	Microplastic (nominal)	Global (11,854)	(van Sebille et al., 2015) [1561]
82,000–578,000 tons	Plankton nets & filtered continuous seawater intake(0.1–0.3 mm mesh)	Microplastic (nominal)	Global (8,209)	(Isobe et al., 2021) [541]